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  • 1.
    Aalto, Anne
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Sjoewall, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk immunologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Davidsson, Leif
    Linköpings universitet, Institutionen för medicin och vård, Radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Forsberg, Pia
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Infektionsmedicin. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Smedby, Örjan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Brain magnetic resonance imaging does not contribute to the diagnosis of chronic neuroborreliosis2007Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 7, s. 755-762Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Borrelia infections, especially chronic neuroborreliosis ( NB), may cause considerable diagnostic problems. This diagnosis is based on symptoms and findings in the cerebrospinal fluid but is not always conclusive. Purpose: To evaluate brain magnetic resonance imaging ( MRI) in chronic NB, to compare the findings with healthy controls, and to correlate MRI findings with disease duration. Material and Methods: Sixteen well- characterized patients with chronic NB and 16 matched controls were examined in a 1.5T scanner with a standard head coil. T1- ( with and without gadolinium), T2-, and diffusion- weighted imaging plus fluid- attenuated inversion recovery ( FLAIR) imaging were used. Results: White matter lesions and lesions in the basal ganglia were seen in 12 patients and 10 controls ( no significant difference). Subependymal lesions were detected in patients down to the age of 25 and in the controls down to the age of 43. The number of lesions was correlated to age both in patients ( rho=0.83, P < 0.01) and in controls ( rho=0.61, P < 0.05), but not to the duration of disease. Most lesions were detected with FLAIR, but many also with T2- weighted imaging. Conclusion: A number of MRI findings were detected in patients with chronic NB, although the findings were unspecific when compared with matched controls and did not correlate with disease duration. However, subependymal lesions may constitute a potential finding in chronic NB.

  • 2.
    Abdul Qadhr, Göran
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Molin, Daniel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Suurküla, Madis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Hagberg, Hans
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Whole-body diffusion-weighted imaging compared with FDG-PET/CT in staging of lymphoma patients2011Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, nr 2, s. 173-180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background:

    Diffusion-weighted imaging (DWI) has become increasingly valuable in lymph node imaging, yet the clinical utility of this technique in the staging of lymphoma has not been established.

    Purpose:

    To compare whole-body DWI with FDG-PET/CT in the staging of lymphoma patients.

    Material and Methods:

    Thirty-one patients, eight with Hodgkin lymphoma (HL) and 23 with non-Hodgkin's lymphoma (18 aggressive and five indolent) underwent both whole-body DWI, whole-body MRI (T1W and T2W-STIR) and FDG-PET/CT. Lesions on whole-body DWI were only considered positive if they correlated with lesions on T1W and T2W-STIR images. The staging given by each technique was compared, according to the Ann Arbor staging system. Differences in staging were solved using biopsy results, and clinical and CT follow-ups as standard of reference.

    Results:

    The staging was the same for DWI and FDG-PET/CT in 28 (90.3%) patients and different in three (9.7%). Of the 28 patients with the same staging, 11 had stage IV in both techniques and 17 had stages 0-III. No HL or aggressive non-Hodgkin's lymphoma patients had different staging. Three indolent small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) lymphoma had higher staging with DWI when compared with FDG-PET/CT. One small subcutaneous breast lymphoma was not seen but all other extranodal sites were detected by both techniques.

    Conclusion:

    Whole-body DWI is a promising technique for staging of both (aggressive and indolent) non-Hodgkin's lymphoma and HL.

  • 3.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Båtelsson, Sarah
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Onkamo, Elina
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Wernroth, Lisa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär epidemiologi.
    Nilsson, Thomas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Lönnemark, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Dahlman, Pär
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Split renal function after treatment of small renal masses: comparison between radiofrequency ablation and laparoscopic partial nephrectomy.2021Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 62, nr 9, s. 1248-1256, artikkel-id 284185120956281Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) and laparoscopic partial nephrectomy (LPN) are used to treat small renal masses (SRM; ≤4 cm), although there are conflicting results in the changes in creatinine and estimated glomerular filtration rate (eGFR) after treatment. On contrast-enhanced computed tomography (CE-CT) images, the quantity and quality of renal function can be evaluated by calculating the split renal function (SRF).

    PURPOSE: To compare renal function after RFA or LPN treatment of SRMs through evaluation of the SRF in the affected kidney.

    MATERIAL AND METHODS: Single T1a renal tumors successfully treated with RFA (n = 60) or LPN (n = 31) were retrospectively compared. The SRF was calculated on pre-treatment CE-CT images and the first follow-up exam after completed treatment. Serum creatinine and eGFR values were collected simultaneously. To compare renal function outcomes, Student's t-test and multivariable linear regression models (adjusted to RFA/LPN treatment, pre-treatment SRF/eGFR, BMI, age, tumor characteristics, and Charlson Comorbidity Index) were used.

    RESULTS: SRF was reduced in both groups, although reduction was greater in the LPN group (LPN -5.7%) than in the RFA group (RFA -3.5%; P = 0.013). After adjusted analysis, the LPN group still had greater SRF reduction (difference 3.2%, 95% confidence interval 1.3-1.5; P = 0.001). There was no difference between groups in the change of creatinine/eGFR after treatment.

    CONCLUSION: Both RFA and LPN are nephron-sparing when treating SRMs. However, in this series, reduction of SRF in the affected kidney was smaller after RFA, having a more favorable preservation of renal function than LPN.

    Fulltekst (pdf)
    fulltext
  • 4.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Dahlman, Pär
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Brekkan, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Lönnemark, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Microwave ablation of 105 T1 renal tumors: technique efficacy with a mean follow-up of two years2024Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 65, nr 3, s. 294-301Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Thermal ablation (TA) with radiofrequency (RFA) or cryoablation (CA) are established treatments for small renal masses (≤4 cm). Microwave ablation (MWA) has several potential benefits (decreased ablation time, less susceptibility to heat-sink, higher lesion temperatures than RFA) but is still considered experimental considering the available small-sample studies with short follow-up.

    Purpose

    To evaluate technique efficacy and complications of our initial experience of renal tumors treated using percutaneous MWA with a curative intent.

    Material and Methods

    A total of 105 renal tumors (in 93 patients) were treated between April 2014 and August 2017. MWA was performed percutaneously with computed tomography (CT) guidance under conscious sedation (n=82) or full anesthesia. Patients were followed with contrast-enhanced CT scans at six months and yearly thereafter for a minimum of five years. The mean follow-up time was 2.1 years. The percentage of tumors completely ablated in a single session (primary efficacy rate) and those successfully treated after repeat ablation (secondary efficacy rate) were recorded. Patient and tumor characteristics as well as complications were collected retrospectively.

    Results

    The median patient age was 70 years and median tumor size was 25 mm. Primary efficacy rate was 96.2% (101/105 tumors). After including two residual tumors for a second ablation session, secondary efficacy was 97.1% (102/105). Periprocedural complications were found in 5.2% (5/95) sessions: four Clavien-Dindo I and one Clavien-Dindo IIIa. One postprocedural Clavien-Dindo II complication was found.

    Conclusion

    MWA has high efficacy rates and few complications compared to other TA methods at a mean follow-up of two years.

    Fulltekst (pdf)
    fulltext
  • 5.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Ladjevardi, Sam
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Brekkan, Einar
    Uppsala University Hospital, Urology, Uppsala, Sweden.
    Häggman, Michael
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Lönnemark, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Wernroth, Lisa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär epidemiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors: A modified R.E.N.A.L nephrometry score adjusted comparison2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, nr 2, s. 260-268Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Comparable oncological outcomes have been seen after surgical nephrectomy and thermal ablation of renal tumors recently. However, periprocedural outcome needs to be assessed for aiding treatment decision.

    Purpose: To compare efficacy rates and periprocedural outcome (technical success, session time, hospitalization time, and complications) after renal tumor treatment with laparoscopic partial nephrectomy (LPN) or radiofrequency ablation (RFA).

    Material and Methods: The initial experience with 49 (treated with LPN) and 84 (treated with RFA) consecutive patients for a single renal tumor (diameter ≤ 5 cm, limited to the kidney) during 2007-2014 was evaluated. Patient and tumor characteristics, efficacy rates, and periprocedural outcome were collected retrospectively. The stratified Mantel Haenzel and Van Elteren tests, adjusted for tumor complexity (with the modified R.E.N.A.L nephrometry score [m-RNS]), were used to assess differences in treatment outcomes.

    Results: Primary efficacy rate was 98% for LPN and 85.7% for RFA; secondary efficacy rate was 93.9% for LPN and 95.2% for RFA; and technical success rate was 87.8% for LPN and 100% for RFA. Median session (m-RNS adjusted P < 0.001; LPN 215 min, RFA 137 min) and median hospitalization time were longer after LPN (m-RNS adjusted P < 0.001; LPN 5 days, RFA 2 days). Side effects were uncommon (LPN 2%, RFA 4.8%). Complications were more frequent after LPN (m-RNS adjusted P < 0.001; LPN 42.9%, RFA 10.7%).

    Conclusion: Both methods achieved equivalent secondary efficacy rates. RFA included several treatment sessions, but session and hospitalization times were shorter, and complications were less frequent than for LPN. The differences remained after adjustment for renal tumor complexity.

  • 6.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Lönnemark, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Brekkan, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Dahlman, Pär
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Wernroth, Lisa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Uppsala kliniska forskningscentrum (UCR). Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär epidemiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Predictive factors for complete renal tumor ablation using RFA2016Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, nr 7, s. 886-893Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

    PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

    MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

    RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

    CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

  • 7.
    Ahlqvist, Jan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Isberg, A M
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Bone demarcation of the temporomandibular joint. Validity of clinical assessment of bone thickness by means of CT.1998Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, nr 6, s. 649-55Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To study the CT depiction of bone demarcations in the temporomandibular joint, using conventional window level and window width; and to evaluate observer performance in estimating bone thickness in these images.

    MATERIAL AND METHODS: Seven joint specimens were imaged by CT and then cryosectioned. The measurements of bone wall thickness in the images were compared to the true bone thickness at each cutting level. In addition, 4 experienced radiologists estimated the thickness of the bone walls in the images.

    RESULTS: The relative difference between the CT reproduction and the true bone thickness was small for bone walls thicker than 2 mm. This difference increased with the decrease in bone thickness and the increase in the inclination of the bone wall from the perpendicular to the image plane. Bone walls thinner than 1 mm were reproduced as considerably thicker than their true thickness. This resulted in a clinical overestimation of bone thickness.

    CONCLUSION: Both the CT representation and the interpretation of bone demarcation in the temporomandibular joint may constitute a problem. Partial volume averaging effects can result in an overestimation of bone dimensions amounting to 200% for thin bones. The central white zone in images of thin bone walls obtained with the parameters described here could serve as an indicator that could help to reduce the risk of overestimating bone thickness.

  • 8.
    Ahlström, Håkan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Gehl, H B
    Overview of MnDPDP as a pancreas-specific contrast agent for MR imaging1997Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 4 Pt 2, s. 660-664Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE:

    To describe and discuss previous and ongoing clinical and experimental studies with MnDPDP (Teslascan) as a pancreas-specific contrast agent for MR imaging.

    MATERIAL AND METHODS:

    All results, both experimental and clinical, applying MnDPDP as a pancreas-specific contrast agent for MR imaging, were collected.

    RESULTS:

    An increase of up to 100% in signal intensity was seen in normal pancreatic parenchyma, reaching its maximum approximately 25 min after the beginning of MnDPDP administration. Maximal enhancement was sustained for 4 h. Enhancement was only seen in the T1-weighted images. No enhancement was observed in tumours and an increase in contrast-to-noise of about 200% was obtained. The uptake of MnDPDP in pancreatitis compared with normal pancreatic parenchyma was decreased in an animal model.

    CONCLUSION:

    Improved depiction and demarcation of pancreatic tumours with MR imaging were obtained after administration of MnDPDP. MR imaging with and without MnDPDP might be valuable for staging of pancreatitis.

  • 9.
    Ahlström, Håkan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Grama, D
    Eriksson, Barbro
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Öberg, Kjell
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Lörelius, L-E
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Preoperative localization of endocrine pancreatic tumours by intra-arterial dynamic computed tomography1990Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 31, nr 2, s. 171-175Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Eleven patients with biochemically confirmed endocrine pancreatic tumours were examined with intra-arterial (i.a.) dynamic computed tomography (CT) and angiography preoperatively. Seven of the patients suffered from the multiple endocrine neoplasia type 1 (MEN-1) syndrome. All patients were operated upon and surgical palpation and ultrasound were the peroperative localization methods. Of the 33 tumours which were found at histopathologic analysis of the resected specimens in the 11 patients, 7 tumours in 7 patients were correctly localized by both i.a. dynamic CT and angiography. Six patients with MEN-1 syndrome had multiple tumours and this group of patients together had 28 tumours, of which 5 (18%) were localized preoperatively by both CT and angiography. I.a. dynamic CT, with the technique used by us, does not seem to improve the localization of endocrine pancreatic tumours, especially in the rare group of MEN-1 patients, as compared with angiography.

  • 10.
    Ahlström, Håkan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Malmström, Per-Uno
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Letocha, H
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Andersson, J
    Institutionen för läkemedelskemi; Plattformen för preklinisk PET, Uppsala university, Uppsala.
    Långström, Bengt
    Institutionen för läkemedelskemi; Plattformen för preklinisk PET, Uppsala university, Uppsala.
    Nilsson, S
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Positron emission tomography in the diagnosis and staging of urinary bladder cancer1996Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 37, nr 2, s. 180-185Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE:

    Evaluation of positron emission tomography (PET) using (18)fl 18F-2-fluoro-2-deoxy-D-glucose (18FDG) and L-methyl-11C-methionine in the diagnosis and staging of urinary bladder carcinoma.

    MATERIAL AND METHODS:

    Twenty-three patients with biopsy-proven urinary bladder carcinoma were examined with PET after intravenous injection of 11C-methionine; 2 were also examined with 18FDG. The results from the PET investigations were compared with CT or MR findings and TNM classification before and after treatment.

    RESULTS:

    The urinary excretion of 18FDG prevented distinction of the primary tumour from the surrounding tracer. With 11C-methionine it was possible to detect 18/23 primary tumours. A trend was seen, suggesting that the higher the uptake values of 11C-methionine in the tumour, the greater the tumour stage.

    CONCLUSION:

    It is possible to visualize urinary bladder tumours larger than 1 cm in diameter with PET using (11)C-methionine, but the value of the method in the staging of the lesions is not superior to conventional methods.

  • 11.
    Ahnfelt, Anders
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Dahlman, Pär
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Segelsjö, Monica
    Magnusson, Mats O
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Accuracy of iodine quantification using dual-energy computed tomography with focus on low concentrations.2022Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 63, nr 5, s. 623-631, artikkel-id 2841851211009462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Iodine quantification using dual-energy computed tomography (DECT) is helpful in characterizing, and follow-up after treatment of tumors. Some malignant masses, for instance papillary renal cell carcinomas (p-RCC), are hard to differentiate from benign lesions because of very low contrast enhancement. In these cases, iodine concentrations might be very low, and it is therefore important that iodine quantification is reliable even at low concentrations if this technique is used.

    PURPOSE: To examine the accuracy of iodine quantification and to determine whether it is also accurate for low iodine concentrations.

    MATERIAL AND METHODS: Twenty-six syringes with different iodine concentrations (0-30 mg I/mL) were scanned in a phantom model using a DECT scanner with two different kilovoltage and image reconstruction settings. Iodine concentrations were measured and compared to known concentration. Absolute and relative errors were calculated.

    RESULTS: For concentrations of 1 mg I/mL or higher, there was an excellent correlation between true and measured iodine concentrations for all settings (R = 0.999-1.000; P < 0.001). For concentrations <1.0 mg I/mL, the relative error was greater. Absolute and relative errors were smaller using tube voltages of 80/Sn140 kV than 100/Sn140 kV (P < 0.01). Reconstructions using a 3.0-mm slice thickness had less variance between repeated acquisitions versus 0.6 mm (P < 0.001).

    CONCLUSION: Iodine quantification using DECT was in general very accurate, but for concentrations < 1.0 mg I/mL the technique was less reliable. Using a tube voltage with larger spectral separation was more accurate and the result was more reproducible using thicker image reconstructions.

  • 12.
    Alagic, Zlatan
    et al.
    Karolinska Univ Hosp, Funct Unit Musculoskeletal Radiol Funct Imaging &, S-17176 Stockholm, Sweden.;Karolinska Inst, Clin Sci Intervent & Technol CLINTEC, Stockholm, Sweden..
    Alagic, Haris
    Karolinska Inst, Inst Mol Med & Surg MMK, Diagnost Radiol, Stockholm, Sweden..
    Bujila, Robert
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Medicinsk bildfysik.
    Srivastava, Subhash
    Karolinska Univ Hosp, Funct Unit Musculoskeletal Radiol Funct Imaging &, S-17176 Stockholm, Sweden..
    Jasim, Saif
    Karolinska Univ Hosp, Funct Unit Musculoskeletal Radiol Funct Imaging &, S-17176 Stockholm, Sweden..
    Lindqvist, Maria
    Karolinska Univ Hosp, Funct Unit Musculoskeletal Radiol Funct Imaging &, S-17176 Stockholm, Sweden..
    Wick, Marius C.
    Karolinska Univ Hosp, Funct Unit Musculoskeletal Radiol Funct Imaging &, S-17176 Stockholm, Sweden.;Karolinska Inst, Inst Mol Med & Surg MMK, Diagnost Radiol, Stockholm, Sweden..
    First experiences of a low-dose protocol for CT-guided musculoskeletal biopsies combining different radiation dose reduction techniques2020Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 61, nr 1, s. 28-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results In group A, the mean total dose-length product (DLP) was 41.2 +/- 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 +/- 22.0 mGy*cm), corresponding to a mean dose reduction of 84% (P<0.001). The mean CTDIvol for the control scans were 1.88 +/- 0.09 mGy and 13.16 +/- 0.40 mGy for groups A and B, respectively (P < 0.001). The success rate in group A was 91.2% and 87.9% in group B (P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.

  • 13.
    Al-Amiry, Bariq
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap. Karolinska Univ Hosp, Dept Radiol, Stockholm, Sweden.
    Mahmood, Sarwar
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Krupic, Ferid
    Sayed-Noor, Arkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Leg lengthening and femoral-offset reduction after total hip arthroplasty: where is the problem - stem or cup positioning?2017Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 9, s. 1125-1131, artikkel-id 0284185116684676Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Restoration of femoral offset (FO) and leg length is an important goal in total hip arthroplasty (THA) as it improves functional outcome. Purpose: To analyze whether the problem of postoperative leg lengthening and FO reduction is related to the femoral stem or acetabular cup positioning or both. Material and Methods: Between September 2010 and April 2013, 172 patients with unilateral primary osteoarthritis treated with THA were included. Postoperative leg-length discrepancy (LLD) and global FO (summation of cup and FO) were measured by two observers using a standardized protocol for evaluation of antero-posterior plain hip radiographs. Patients with postoperative leg lengthening >= 10mm (n = 41) or with reduced global FO >5mm (n = 58) were further studied by comparing the stem and cup length of the operated side with the contralateral side in the lengthening group, and by comparing the stem and cup offset of the operated side with the contralateral side in the FO reduction group. We evaluated also the inter-observer and intra-observer reliability of the radiological measurements. Results: Both observers found that leg lengthening was related to the stem positioning while FO reduction was related to the positioning of both the femoral stem and acetabular cup. Both inter-observer reliability and intra-observer reproducibility were moderate to excellent (intra-class correlation co-efficient, ICC >= 0.69). Conclusion: Post THA leg lengthening was mainly caused by improper femoral stem positioning while global FO reduction resulted from improper positioning of both the femoral stem and the acetabular cup.

  • 14.
    Alemany Ripoll, Montserrat
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Gustafsson, O.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Siösteen, B.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Olsson, Y.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    MR follow-up of small experimental intracranial haemorrhages from hyperacute to subacute phase2002Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, nr 1, s. 2-9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To compare pulse sequences in revealing intracranial bleeding from the hyperacute to subacute phase. MATERIAL AND METHODS: We injected 0.3-1 ml of autologous blood into the brain of 8 rabbits. MR imaging was performed immediately after haematoma creation and then at determined intervals up to 9-12 days. All images were analysed by two observers. After the last MR investigation, the brain was fixed in formalin. The last MR images were compared to the fixed brain sections and to the histologic findings. RESULTS: T2*-weighted GE sequences, both conventional spoiled and echoplanar sequences, revealed the intraparenchymal haematomas as hypointensities in all but 1 case, which was negative from the second day onward (a rabbit with 0.3 ml blood injected). The signal patterns remained unchanged during the follow-up. The haematoma sizes and shapes corresponded well to gross pathology. Blood in the cerebrospinal fluid (CSF) space was detected with T2*-weighted GE sequences in a great majority of the examinations during the first 2 days. The cases with the smallest injected volume of blood were negative. SE sequences were rather insensitive. The FLAIR sequence often revealed blood in CSF spaces but not in the brain. CONCLUSION: T2*-weighted GE sequences are capable of revealing very small intraparenchymal haemorrhages from the hyperacute to the subacute phase, and blood in CSF spaces during at least the first 2 days.

  • 15.
    Alemany Ripoll, Montserrat
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Experimental intracerebral and subarachnoid/intraventricular haemorrhages2002Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, nr 5, s. 464-73Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. MATERIAL AND METHODS: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. RESULTS: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90-95% at 0.5 T. Blood in the CSF spaces was significantly (p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. CONCLUSION: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.

  • 16.
    Alshamari, Muhammed
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden; Lund University, Lund, Sweden.
    Norrman, Eva
    Region Örebro län.
    Geijer, Håkan
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Low-dose computed tomography of the lumbar spine: a phantom study on imaging parameters and image quality2014Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, nr 7, s. 824-832Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Lumbar spine radiography has limited diagnostic value but low radiation dose compared with computed tomography (CT). The average effective radiation dose from lumbar spine radiography is about 1.1 mSv. Low-dose lumbar spine CT may be an alternative to increase the diagnostic value at low radiation dose, around 1 mSv.

    Purpose: To determine the optimal settings for low-dose lumbar spine CT simultaneously aiming for the highest diagnostic image quality possible.

    Material and Methods: An ovine lower thoracic and lumbar spine phantom, with all soft tissues around the vertebrae preserved except the skin, was placed in a 20 L plastic container filled with water. The phantom was scanned repeatedly with various technical settings; different tube potential, reference mAs, and with different convolution filters. Five radiologists evaluated the image quality according to a modification of the European guidelines for multislice computed tomography (MSCT) quality criteria for lumbar spine CT 2004. In a visual comparison the different scans were also ranked subjectively according to perceived image quality. Image noise and contrast were measured.

    Results: A tube potential of 120 kV with reference mAs 30 and medium or medium smooth convolution filter gave the best image quality at a sub-millisievert dose level, i.e. with an effective dose comparable to that from lumbar spine radiography.

    Conclusion: Low-dose lumbar spine CT thus opens a possibility to substitute lumbar spine radiography with CT without obvious increase in radiation dose.

  • 17.
    Alshamari, Muhammed
    et al.
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden; Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Norrman, Eva
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Lidén, Mats
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Krauss, Wolfgang
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Jendeberg, Johan
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Magnuson, Anders
    Region Örebro län.
    Geijer, Håkan
    Örebro universitet, Institutionen för medicinska vetenskaper. Region Örebro län. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine2017Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 6, s. 702-709Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality.

    Purpose: To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose.

    Material and Methods: Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed.

    Results: There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR.

    Conclusion: Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.

  • 18.
    Alshamari, Muhammed
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Geijer, Mats
    Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Norrman, Eva
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Medical Physics,, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Lidén, Mats
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Krauss, Wolfgang
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Wilamowski, Franciszek
    Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Håkan
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Low dose CT of the lumbar spine compared with radiography: a study on image quality with implications for clinical practice2016Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, nr 5, s. 602-611Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Lumbar spine radiography is often performed instead of CT for radiation dose concerns.

    Purpose: To compare image quality and diagnostic information from low dose lumbar spine CT at an effective dose of about 1 mSv with lumbar spine radiography.

    Material and Methods: Fifty-one patients were examined by both methods. Five reviewers scored all examinations on eight image quality criteria using a five-graded scale and also assessed three common pathologic changes.

    Results: Low dose CT scored better than radiography on the following: sharp reproduction of disc profile and vertebral end-plates (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.5), intervertebral foramina and pedicles (OR, 4.3; 95% CI, 3.1-5.9), intervertebral joints (OR, 139; 95% CI, 59-326), spinous and transverse processes (OR, 7.0; 95% CI, 4.3-11.2), sacro-iliac joints (OR, 4.2; 95% CI, 3.2-5.7), reproduction of the adjacent soft tissues (OR, 2.9; 95% CI, 2.1-4.0), and absence of any obscuring superimposed gastrointestinal gas and contents (OR, 188; 95% CI, 66-539). Radiography scored better on sharp reproduction of cortical and trabecular bone (OR, 0.3; 95% CI, 0.2-0.4). The reviewers visualized disk degeneration, spondylosis/diffuse idiopathic skeletal hyperostosis (DISH) and intervertebral joint osteoarthritis more clearly and were more certain with low dose CT. Mean time to review low dose CT was 204 s (95% CI, 194-214 s.), radiography 152 s (95% CI, 146-158 s.). The effective dose for low dose CT was 1.0-1.1 mSv, for radiography 0.7 mSv.

    Conclusion: Low dose lumbar spine CT at about 1 mSv has superior image quality to lumbar spine radiography with more anatomical and diagnostic information.

  • 19.
    Arteaga-Marrero, Natalia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Department of Physics and Technology, University of Bergen, Bergen, Norway.
    Mainou-Gomez, Jose F.
    Rygh, Cecilie Brekke
    Lutay, Nataliya
    Roehrich, Dieter
    Reed, Rolf K.
    Olsen, Dag R.
    Radiation treatment monitoring with DCE-US in CWR22 prostate tumor xenografts2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, nr 6, s. 788-797Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Longitudinal monitoring of potential radiotherapy treatment effects can be determined by dynamic contrast-enhanced ultrasound (DCE-US).

    Purpose: To assess functional parameters by means of DCE-US in a murine subcutaneous model of human prostate cancer, and their relationship to dose deposition and time-frame after treatment. A special focus has been placed to evaluate the vascular heterogeneity of the tumor and on the most suitable data analysis approach that reflects this heterogeneity.

    Material and Methods: In vivo DCE-US was acquired 24 h and 48 h after radiation treatment with a single dose of 7.5 Gy and 10 Gy, respectively. Tumor vasculature was characterized pixelwise using the Brix pharmacokinetic analysis of the time-intensity curves.

    Results: Longitudinal changes were detected (P < 0.001) at 24 h and 48 h after treatment. At 48 h, the eliminating rate constant of the contrast agent from the plasma, kel, was correlated (P ≤ 0.05) positively with microvessel density (MVD; rτ = 0.7) and negatively with necrosis (rτ = –0.6) for the treated group. Furthermore, Akep, a parameter related to transcapillary transport properties, was also correlated to MVD (rτ = 0.6, P ≤ 0.05).

    Conclusion: DCE-US has been shown to detect vascular changes at a very early stage after radiotherapy, which is a great advantage since DCE-US is non-invasive, available at most hospitals, and is low in cost compared to other techniques used in clinical practice.

  • 20.
    Berg, K
    et al.
    Norwegian University of Science and Technology.
    Skarra, S
    Norwegian University of Science and Technology.
    Bruvold, M
    Norwegian University of Science and Technology.
    Brurok, H
    Norwegian University of Science and Technology.
    Karlsson, JOG
    Norwegian University of Science and Technology.
    Jynge, Per
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet.
    Iodinated radiographic contrast media possess antioxidant properties in vitro2005Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, nr 8, s. 815-822Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To study potential properties of iodinated radiographic contrast media (IRCM) for intravascular use in in vitro free radical generating reactions. Material and Methods: Superoxide (center dot O-2(-)) and hydroxyl ((OH)-O-center dot) radicals were generated in xanthine oxidase and Fenton reactions. center dot O-2(-) was assayed by the nitroblue tetrazolium (NBT) method, whereas (OH)-O-center dot was assayed by an aromatic hydroxylation (2-hydroxybenzoic acid) method. Total antioxidant status (TAS) of test substances was determined by a colorimetric assay. Finally, acetyl-cholinesterase (AChE) activity was measured in the absence and presence of IRCM. Results: High concentrations (greater than50 mM) of IRCM inhibited center dot O-2(-) production, ionic more than non-ionic IRCM. Medium concentrations (25-50 mM) of IRCM reduced (OH)-O-center dot production, and both types of IRCM were equally potent. Low concentrations (less than25 mM) of non-ionic IRCM displayed higher antioxidant capacity than their ionic counterparts when tested in the TAS assay. Visipaque 320 (iodixanol) was found to have the highest TAS value, followed by Omnipaque 350(R) (iohexol), Hexabrix 320(R) (ioxaglate), and Urografin 370(R) (diatrizoate). Conclusion: IRCM have in vitro antioxidant properties in concentrations relevant for their clinical application. These properties may therefore be of potential importance when evaluating IRCM effects in vivo, particularly those concerning cardiovascular and renal function.

  • 21.
    Berstad, Audun E.
    et al.
    Oslo Univ Hosp, Dept Radiol, Oslo, Norway.
    Brabrand, Knut
    Oslo Univ Hosp, Dept Radiol, Oslo, Norway.
    Horneland, Rune
    Oslo Univ Hosp, Surg Dept, Sect Transplant Surg, Oslo, Norway.
    Syversveen, Trygve
    Oslo Univ Hosp, Dept Radiol, Oslo, Norway.
    Haugaa, Hakon
    Oslo Univ Hosp, Dept Anesthesiol, Oslo, Norway;Lovisenberg Diaconal Univ Coll, Oslo, Norway.
    Enssen, Trond G.
    Oslo Univ Hosp, Dept Transplantat Med, Sect Nephrol, Oslo, Norway;Arctic Univ Norway, Metab & Renal Res Grp, Tromso, Norway;Univ Oslo, Med Fac, Oslo, Norway.
    Foss, Aksel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Transplantationskirurgi. Oslo Univ Hosp, Dept Transplantat Med.
    Microbubble contrast-enhanced ultrasound in the vascular evaluation after pancreas transplantation: a single-center experience2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, nr 10, s. 1224-1231Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Arterial and venous thrombosis are feared complications of pancreas transplantation (PTx). Microbubble contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technique that can augment diagnostic capabilities of transplant organ perfusion. Purpose To document the state to which CEUS can improve the vascular evaluation of PTx compared to conventional Doppler ultrasound (US) directly after surgery. Material and Methods A total of 129 consecutive PTx in 128 adult patients were eligible for inclusion. The duodenal segment of the graft was anastomosed to the native duodenum. Within 12 h postoperatively, graft circulation was monitored by Doppler US in 116 PTx performed in 116 patients (69 men, 47 women; mean age =41 years). CEUS was performed with a sulfur hexafluoride-containing contrast agent (SonoVue) intravenously if the examiner was not able to confirm normal graft circulation. Image quality was documented by two independent observers on a 4-point scale: 1 = excellent; 2 = minor diagnostic limitations; 3 = major diagnostic limitations; and 4 = non-diagnostic. Results In the early postoperative phase, 79 (68%) of 116 PTx were examined with Doppler US only. Of these, 52 were of excellent quality (grade 1), 22 of good quality (grade 2), and five were of grade 3 or 4 quality. Thirty-seven (32%) examinations were supplemented by CEUS. CEUS significantly improved examination quality compared to Doppler US alone (median visualization score 1.5 vs. 2.5, respectively; P < 0.0001). Conclusion CEUS can significantly improve vascular evaluation of PTx compared to Doppler US alone in the early postoperative phase.

  • 22.
    Bjerner, Tomas
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Haglund, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Gastrointestinalkirurgi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    3D surface rendering of images from multiple MR pulse sequences in the pre-operative evaluation of hepatic lesions1998Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, nr 6, s. 698-700Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Segmentation and reconstruction took 1-2 h. To be able to combine the volumes from the different data sets, certain criteria had to be fulfilled: a) the field of view had to be constant; b) the same volume had to be scanned every time which meant that the slice thickness and the number of slices could be adjusted as long as the volume covered was the same; and c) the positioning of each volume had to be identical between every scan. The resulting 3D reconstruction gave the surgeon a clear appreciation of the different lesions and their relation to the different liver segments in the pre-operative planning of hepatic resections.

  • 23.
    Björkman, Ann-Sofi
    et al.
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Koskinen, Seppo K.
    Karolinska Inst, Sweden.
    Lindblom, Maria
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Persson, Anders
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Karolinska Inst, Sweden.
    Diagnostic accuracy of dual-energy CT for detection of bone marrow lesions in the subacutely injured knee with MRI as reference method2020Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 61, nr 6, s. 749-759Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Dual-energy computer tomography (DECT) can detect post-traumatic bone marrow lesions. Prospective studies of the knee with large numbers of participants and intra-observer agreement assessment are limited. Purpose To investigate the diagnostic accuracy of DECT in detecting bone marrow lesions as well as estimating the bone marrow lesion volume in patients with suspected anterior cruciate ligament trauma with magnetic resonance imaging (MRI) as reference standard. Material and Methods Forty-eight consecutive patients with suspected anterior cruciate ligament injury were imaged bilaterally with DECT within a mean of 25 days (range 4-55 days) following injury and MRI within seven days of DECT. Two readers analyzed DECT virtual non-calcium-blinded images. Consensus MRI was reference standard. Intra- and inter-observer agreement were determined using weighted kappa statistics. Sensitivity, specificity, and negative and positive predictive values were calculated. Bone marrow lesion volumes were measured; for comparison, intra-class correlation coefficient was used. Results The 48 patients (26 men, 22 women; mean age 23 years, age range 15-37 years) were imaged bilaterally yielding 52 knees with bone marrow lesions, of which 44 were in the femur and 41 were in the tibia. Intra- and inter-observer agreement to detect bone marrow lesions was moderate and fair to moderate (kappa 0.54-0.66, 95% confidence interval [CI] 0.39-0.80 and 0.37-0.41, 95% CI 0.20-0.57) and overall sensitivity and specificity were 70.1% and 69.1%, respectively. Positive and negative predictive values were 72.9% and 66.1%, respectively. Bone marrow lesion volumes showed excellent intra- and inter-observer agreement (0.83-0.91, 95% CI 0.74-0.94 and 0.76-0.78, 95% CI 0.57-0.87). Conclusion The diagnostic performance of DECT to detect bone marrow lesions in the subacutely injured knee was moderate with intra- and inter-observer agreement ranging from moderate to substantial and fair to moderate. Bone marrow lesion volume correlation was excellent.

  • 24.
    Björkman, Berit
    et al.
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för naturvetenskap och biomedicin. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD.
    Bendroth, R.
    Lund University, Lund, Sweden.
    Andersson, B. T.
    Dep Health Sciences, Lund, Sweden.
    Swedish radiographer’s experiences of their work-performance when possessing increased knowledge in reporting2017Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 1 Suppl., s. 24-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Introduction: Radiographers are today facing various challenges as the technical equipment is getting more advanced and the examinations encounter patients with complex medical records. Furthermore, in the Swedish context, radiology departments are struggling with shortage of both radiologists and radiographers. Following, this has led to a work-situation where radiologists are not always in place during emergency duty, and radiographers’are taking on additional responsibility. Hence, there is a need for further and deeper knowledge within areas that previously was undertaken solely by radiologists. One such area is reporting; and a 7.5 ECTS course was designed and offered to registered radiographers. The aim was to investigate radiographer’s experience of their work-performance and contribution to the clinic after attending this particular course in reporting.

    Methods: The study had a qualitative design based on individual and semi-structured interviews with 34 radiographers who attended the course in reporting the fall of 2013, 2014 and 2015. The interviews were transcribed verbatim and analysed using qualitative content analysis.

    Results: The analysis resulted in a comprehensive theme: Width and depth in the professional practice. This theme embraced three categories: Increased knowledge, Professional recognition, Work satisfaction.

    Conclusions: Increased knowledge in reporting is necessary to meet the demands from the diagnostic departments. A course in reporting on advanced level is a tool for deeper understanding of the medical image. However, there will still be challenges and constraints during the path to be a fully specialized radiographer in reporting. There is a need for more courses in this area on the second and third level.

  • 25.
    Björkman, Berit
    et al.
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för naturvetenskap och biomedicin. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD.
    Gimbler Berglund, Ingalill
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för omvårdnad. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD.
    Faresjö, Maria
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för naturvetenskap och biomedicin. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD. Högskolan i Jönköping, Hälsohögskolan, HHJ. Biomedicinsk plattform.
    Enskär, Karin
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för omvårdnad. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD.
    Huus, Karina
    Högskolan i Jönköping, Hälsohögskolan, HHJ, Avd. för omvårdnad. Högskolan i Jönköping, Hälsohögskolan, HHJ. CHILD.
    Are radiographers prepared to meet children with special needs, when seen for an examination?2017Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 1 Suppl., s. 16-16Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Introduction: Anxiety is often experienced by children undergoing health care procedures, and children with autism spectrum disorders (ADS) experience more anxiety than typically developed children. A prerequisite for obtaining an optimum procedure is firstly based on the health care provider’s knowledge about children with ASD, but may also depend on the use of guidelines. Two previous national surveys showed, that none radiology or paediatric departments and a minority of anaesthesiology departments throughout Sweden use specific guidelines when seeing children with ASD. Following, the purpose was to develop guidelines to use when caring for and preparing children with ASD in those settings.

    Methods: A modified Delphi method was used, including19 experts identified from the two afore mentioned surveys. The questions considered in the process, proceeded from previous research and the results from the surveys. The experts’ responses regarding the importance of each item, were analysed and scrutinized between each round.

    Results: The Delphi process resulted in guidelines consisting of 15 items and a checklist with 16 aspects. The items cover the areas: planning and involving parents, features in the environment, use of time, communication, thehealth care professionals. The checklist covers the child’spattern of communication, anxiety, sensory stimuli, special interests and likes/dislikes.

    Conclusions: To obtain an optimum caring encounter when a child with ASD is seen in the preoperative and radiology setting, a meticulous planning is important and the environment should be adjusted for the needs of the child. To accomplish this, guidelines need to be in place and be followed.

  • 26.
    Björkman, Henrik
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Eklöf, Hampus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Wadström, Jonas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Andersson, L-G.
    Nyman, Rickard
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Split renal function in patients with suspected renal artery stenosis: a comparison between gamma camera renography and two methods of measurements with computed tomography2006Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, nr 1, s. 107-113Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To validate a method for calculating split renal function from computed tomography (CT) compared with gamma camera renography, and to test a new method for the measurement based on a volume-rendering technique. MATERIAL AND METHODS: Thirty-eight patients, aged 65.7 +/- 11.6 (range 37.8-82.1) years, who had undergone both CT angiography and gamma camera renography for a suspected renal artery stenosis were included in this study. Split renal function was calculated from the CT examinations by measuring area and mean attenuation in the image slices of the kidneys, and also by measuring volume and mean attenuation from a 3D reconstruction of the kidneys. Gamma camera renography with 99mTc-MAG3 with or without captopril enhancement was used as a reference. RESULTS: The 2D CT method had good correlation with renography (r=0.93). Mean difference was 4.7 +/- 3.6 (0-12) percentage points per kidney. There was also excellent correlation between the two CT methods (r=1.00). CONCLUSION: CT is equivalent to renography in determining split renal function, and the measurement from the CT examination can be made more quickly and equally accurately with a 3D technique.

  • 27. Blystad, I
    et al.
    Warntjes, Jbm
    Smedby, Örjan
    Landtblom, A-M
    Lundberg, P
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Synthetic MRI of the brain in a clinical setting2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 10, s. 1158-1163Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Conventional magnetic resonance imaging (MRI) has relatively long scan times for routine examinations, and the signal intensity of the images is related to the specific MR scanner settings. Due to scanner imperfections and automatic optimizations, it is impossible to compare images in terms of absolute image intensity. Synthetic MRI, a method to generate conventional images based on MR quantification, potentially both decreases examination time and enables quantitative measurements.

    Purpose

    To evaluate synthetic MRI of the brain in a clinical setting by assessment of the contrast, the contrast-to-noise ratio (CNR), and the diagnostic quality compared with conventional MR images.

    Material and Methods

    Twenty-two patients had synthetic imaging added to their clinical MR examination. In each patient, 12 regions of interest were placed in the brain images to measure contrast and CNR. Furthermore, general image quality, probable diagnosis, and lesion conspicuity were investigated.

    Results

    Synthetic T1-weighted turbo spin echo and T2-weighted turbo spin echo images had higher contrast but also a higher level of noise, resulting in a similar CNR compared with conventional images. Synthetic T2-weighted FLAIR images had lower contrast and a higher level of noise, which led to a lower CNR. Synthetic images were generally assessed to be of inferior image quality, but agreed with the clinical diagnosis to the same extent as the conventional images. Lesion conspicuity was higher in the synthetic T1-weighted images, which also had a better agreement with the clinical diagnoses than the conventional T1-weighted images.

    Conclusion

    Synthetic MR can potentially shorten the MR examination time. Even though the image quality is perceived to be inferior, synthetic images agreed with the clinical diagnosis to the same extent as the conventional images in this study.

  • 28.
    Blystad, Ida
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Warntjes, Jan Bertus Marcel
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Landtblom, Anne-Marie
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Neurologiska kliniken.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Larsson, Elna-Marie
    Uppsala University, Sweden .
    Synthetic MRI of the brain in a clinical setting2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 10, s. 1158-1163Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND:

    Conventional magnetic resonance imaging (MRI) has relatively long scan times for routine examinations, and the signal intensity of the images is related to the specific MR scanner settings. Due to scanner imperfections and automatic optimizations, it is impossible to compare images in terms of absolute image intensity. Synthetic MRI, a method to generate conventional images based on MR quantification, potentially both decreases examination time and enables quantitative measurements.

    PURPOSE:

    To evaluate synthetic MRI of the brain in a clinical setting by assessment of the contrast, the contrast-to-noise ratio (CNR), and the diagnostic quality compared with conventional MR images.

    MATERIAL AND METHODS:

    Twenty-two patients had synthetic imaging added to their clinical MR examination. In each patient, 12 regions of interest were placed in the brain images to measure contrast and CNR. Furthermore, general image quality, probable diagnosis, and lesion conspicuity were investigated.

    RESULTS:

    Synthetic T1-weighted turbo spin echo and T2-weighted turbo spin echo images had higher contrast but also a higher level of noise, resulting in a similar CNR compared with conventional images. Synthetic T2-weighted FLAIR images had lower contrast and a higher level of noise, which led to a lower CNR. Synthetic images were generally assessed to be of inferior image quality, but agreed with the clinical diagnosis to the same extent as the conventional images. Lesion conspicuity was higher in the synthetic T1-weighted images, which also had a better agreement with the clinical diagnoses than the conventional T1-weighted images.

    CONCLUSION:

    Synthetic MR can potentially shorten the MR examination time. Even though the image quality is perceived to be inferior, synthetic images agreed with the clinical diagnosis to the same extent as the conventional images in this study.

    Fulltekst (pdf)
    Synthetic MRI of the brain in a clinical setting
  • 29.
    Borgen, Lars
    et al.
    Drammen and Buskerud University of College.
    Kalra, Mannudeep K
    Harvard University.
    Laerum, Frode
    Akershus University Hospital.
    Hachette, Isabelle W
    ContextVision AB.
    Fredriksson, Carina H
    ContextVision AB, Linkoping, Sweden .
    Sandborg, Michael
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Application of adaptive non-linear 2D and 3D postprocessing filters for reduced dose abdominal CT2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 3, s. 335-342Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Abdominal computed tomography (an is a frequently performed imaging procedure, resulting in considerable radiation doses to the patient population. Postprocessing filters are one of several dose reduction measures that might help to reduce radiation doses without loss of image quality. less thanbrgreater than less thanbrgreater thanPurpose: To assess and compare the effect of two- and three-dimensional (2D, 3D) non-linear adaptive filters on reduced dose abdominal CT images. less thanbrgreater than less thanbrgreater thanMaterial and Methods: Two baseline abdominal CT image series with a volume computer tomography dose index (CTDI (vol)) of 12 mGy and 6 mGy were acquired for 12 patients. Reduced dose images were postprocessed with 2D and 3D filters. Six radiologists performed blinded randomized, side-by-side image quality assessments. Objective noise was measured. Data were analyzed using visual grading regression and mixed linear models. less thanbrgreater than less thanbrgreater thanResults: All image quality criteria were rated as superior for 3D filtered images compared to reduced dose baseline and 2D filtered images (P andlt; 0.01). Standard dose images had better image quality than reduced dose 3D filtered images (P andlt; 0.01), but similar image noise. For patients with body mass index (BMI) andlt; 30 kg/m(2) however, 3D filtered images were rated significantly better than normal dose images for two image criteria (P andlt; 0.05), while no significant difference was found for the remaining three image criteria (P andgt; 0.05). There were no significant variations of objective noise between standard dose and 2D or 3D filtered images. less thanbrgreater than less thanbrgreater thanConclusion: The quality of 3D filtered reduced dose abdominal CT images is superior compared to reduced dose unfiltered and 2D filtered images. For patients with BMI andlt; 30 kg/m(2), 3D filtered images are comparable to standard dose images.

    Fulltekst (pdf)
    fulltext
  • 30.
    Borota, Ljubisa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Jangland, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Åslund, Per-Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Ronne-Engström, Elisabeth
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurokirurgi.
    Nyberg, Christoffer
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurokirurgi.
    Mahmoud, Ehab
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Sakaguchi, Takuya
    Patz, Andreas
    Spot fluoroscopy: a novel innovative approach to reduce radiation dose in neurointerventional procedures2017Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 5, s. 600-608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Increased interest in radiation dose reduction in neurointerventional procedures has led to the development of a method called "spot fluoroscopy" (SF), which enables the operator to collimate a rectangular or square region of interest anywhere within the general field of view. This has potential advantages over conventional collimation, which is limited to symmetric collimation centered over the field of view.

    PURPOSE: To evaluate the effect of SF on the radiation dose.

    MATERIAL AND METHODS: Thirty-five patients with intracranial aneurysms were treated with endovascular coiling. SF was used in 16 patients and conventional fluoroscopy in 19. The following parameters were analyzed: the total fluoroscopic time, the total air kerma, the total fluoroscopic dose-area product, and the fluoroscopic dose-area product rate. Statistical differences were determined using the Welch's t-test.

    RESULTS: The use of SF led to a reduction of 50% of the total fluoroscopic dose-area product (CF = 106.21 Gycm(2), SD = 99.06 Gycm(2) versus SF = 51.80 Gycm(2), SD = 21.03 Gycm(2), p = 0.003884) and significant reduction of the total fluoroscopic dose-area product rate (CF = 1.42 Gycm(2)/min, SD = 0.57 Gycm(2)/s versus SF = 0.83 Gycm(2)/min, SD = 0.37 Gycm(2)/min, p = 0.00106). The use of SF did not lead to an increase in fluoroscopy time or an increase in total fluoroscopic cumulative air kerma, regardless of collimation.

    CONCLUSION: The SF function is a new and promising tool for reduction of the radiation dose during neurointerventional procedures.

  • 31.
    Boström Ardin, Annika
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Löfberg, A-M.
    Hellberg, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Andrén, Bertil
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Ljungman, Christer
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Logason, K.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Karacagil, Sadettin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty with duplex scanning2002Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, nr 4, s. 391-395Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: To evaluate the role of duplex scanning in the selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty (PTA).

    MATERIAL AND METHODS: From January 1995 through May 2000, 702 patients (952 limbs), with chronic lower extremity ischemia due to infrainguinal atherosclerotic disease diagnosed by duplex scanning, were retrospectively studied. Diagnostic angiography (130 limbs) or infrainguinal PTA (108 limbs) was performed in 238 limbs. Two investigators retrospectively analyzed the duplex examinations and angiographies in a blinded manner and used similar criteria for the interpretation of lesions suitable or not suitable for PTA.

    RESULTS: The superficial femoral, popliteal and crural artery lesions were correctly selected for PTA in 85%, 66% and 32%, respectively. The accuracy, sensitivity, specificity, negative predictive value and positive predictive value of duplex scanning to appropriately categorize femoropopliteal lesions as suitable or unsuitable for PTA were 89%, 83%, 92%, 94% and 78%, respectively. The accuracy of duplex scanning for predicting the performance of infrainguinal PTA was 83%.

    CONCLUSION: Duplex scanning has an important impact on the selection of treatment modalities in limbs with infrainguinal arterial occlusive disease. Femoropopliteal lesions can be reliably selected to PTA according to duplex scan findings.

  • 32.
    Brismar, Torkel
    et al.
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Dahlström, Nils
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Edsborg, Nick
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Persson, Anders
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Albiin, Nils
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Liver Vessel Enhancement by Gd-BOPTA and Gc-EOB-DTPA – a Comparison in Healthy Volunteers.2009Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 7, s. 709-715Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: A thorough understanding of magnetic resonance (MR) contrast media dynamics makes it possible to choose the optimal contrast media for each investigation. Differences in visualizing hepatobiliary function between Gd-BOPTA and Gd-EOB-DTPA have previously been demonstrated, but less has been published regarding differences in liver vessel visualization.Purpose: To compare the liver vessel and liver parenchymal enhancement dynamics of Gd-BOPTA (MultiHance®) and Gd-EOB-DTPA (Primovist®). Material and Methods: The signal intensity of the liver parenchyma, the common hepatic artery, the middle hepatic vein, and a segmental branch of the right portal vein, was obtained in 10 healthy volunteers before contrast media administration, during arterial and portal venous phases, and 10, 20, 30, 40 and 130 minutes after intravenous contrast medium injection, but due to scanner limitations not during the hepatic venous phase. Results: Maximum enhancement of liver parenchyma was observed from the portal venous phase until 130 minutes after Gd-BOPTA administration and from 10 minutes to 40 minutes after Gd-EOB-DTPA. There was no difference in maximum enhancement of liver parenchyma between the two contrast media. When using Gd-BOPTA, the vascular contrast enhancement was still apparent 40 minutes after injection, but had vanished 10 minutes after Gd-EOB-DTPA injection. The maximum difference in signal intensity between the vessels and the liver parenchyma was significantly greater with Gd-BOPTA than with Gd-EOB-DTPA (p<0.0001). Conclusion: At the dosage used in this study Gd-BOPTA yields higher maximum enhancement of the hepatic artery, portal vein and middle hepatic vein during the arterial and the portal venous phase and during the delayed phases than Gd-EOB-DTPA does, whereas there is no difference in liver parenchymal enhancement between the two contrast agents.

  • 33.
    Brodén, Cyrus
    et al.
    Department of Surgery and Cancer, Imperial College London, St Mary’s Hospital, London, UK2Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Division of Orthopaedics, Stockholm, Sweden.
    Giles, Joshua W.
    Department of Mechanical Engineering, University of Victoria, Victoria, BC, Canada4Mechatronics in Medicine Laboratory, Mechanical Engineering, Imperial College London, London, UK.
    Popat, Ravi
    Department of Bioengineering, Imperial College London, London, UK.
    Fetherston, Shirley
    Department of Radiology, St Mary’s Hospital, Imperial College Healthcare NHS Trust, London, UK.
    Olivecrona, Henrik
    Karolinska Institutet, Sweden.
    Sandberg, Olof
    Sectra, Linköping, Sweden.
    Maguire Jr., Gerald Q.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Kommunikationssystem, CoS.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Sködenberg, Olof
    Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Division of Orthopaedics, Stockholm, Sweden.
    Emery, Roger
    Department of Surgery and Cancer, Imperial College London, St Mary’s Hospital, London, UK.
    Accuracy and precision of a CT method for assessing migration in shoulder arthroplasty: an experimental study2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Radiostereometric analysis (RSA) is the gold standard to measure early implant migration which is a predictive factor for implant survival. Purpose: To validate an alternative computed tomography (CT) technique to measure implant migration in shoulder arthroplasty. Material and Methods: A cadaver proximal humerus and a scapula, which had tantalum beads incorporated within them, were prepared to accept a short-stemmed humeral component and a two-pegged glenoid component of a commercial total shoulder arthroplasty (TSA) system. A five degree of freedom micrometer and goniometer equipped rig was used to translate and rotate the implant components relative to the respective bone to predetermined positions. Double CT examinations were performed for each position and CT motion analysis software (CTMA) was used to assess these movements. The accuracy and precision of the software was estimated using the rig’s micrometers and goniometers as the gold standard. The technique’s effective dose was also assessed. Results: The accuracy was in the range of 0.07–0.23 mm in translation and 0.22–0.71° in rotation. The precision was in the range of 0.08–0.15 mm in translation and 0.23–0.54° in rotation. The mean effective dose for the CT scans was calculated to be 0.27 mSv. Conclusion: In this experimental setting, accuracy, precision, and effective dose of the CTMA technique were found to be comparable to that of RSA. Therefore, we believe clinical studies are warranted to determine if CTMA is a suitable alternative to traditional RSA for migration measurements in TSA.

  • 34. Carlson, K
    et al.
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Nyman, Rickard
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Simonsson, Bengt
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    MR imaging of multiple myeloma in tumour mass measurement at diagnosis and during treatment1995Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, nr 1, s. 9-14Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The bone marrow of the spine, pelvis and proximal femora was examined with MR imaging at diagnosis in 30 cases of multiple myeloma (MM), and during treatment on 69 occasions. The MR pattern was normal, focal or diffuse and correlated to stage. A tumour mass index (TMI) was calculated by estimating the total myeloma mass visualised at MR imaging. The TMI correlated significantly with stage, lytic bone lesions, serum calcium, serum beta-2-microglobulin and survival. No abnormalities were seen at MR investigation in 4 of 6 patients classified as stage II because of osteoporosis only. Therapy efficacy evaluation with MR imaging corresponded to clinical evaluation on 54 of the 69 occasions. MR examination of bone marrow in MM patients can be used for tumour mass assessment, both at diagnosis and during follow-up. Valuable information can be obtained when the tumour mass is difficult to estimate using clinical criteria, e.g. in non-secretory MM or when osteoporosis is the only variable indicating an increase in the tumour mass.

  • 35. Cavallin, Lena
    et al.
    Bronge, Lena
    Zhang, Yi
    Oksengård, Anne-Rita
    Wahlund, Lars-Olof
    Fratiglioni, Laura
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Axelsson, Rimma
    Comparison between visual assessment of MTA and hippocampal volumes in an elderly, non-demented population2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 5, s. 573-579Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background It is important to have a replicable easy method for monitoring atrophy progression in Alzheimer's disease. Volumetric methods for calculating hippocampal volume are time-consuming and commonly used in research. Visual assessments of medial temporal lobe atrophy (vaMTA) is a rapid method for clinical use. This method has not been tested in a large non-demented population in comparison with volumetry mesurements. Since hippocampal volume decreases with time even in normal aging there is also a need to study the normal age differences of medial temporal lobe atrophy.                     

    Purpose To compare visual assessment of medial temporal lobe atrophy (vaMTA) with hippocampal volume in a healthy, non-demented elderly population. To describe normal ageing using vaMTA.                     

    Material and Methods Non-demented individuals aged 60, 66, 72, 78, 81, 84, and ≥87 years old were recruited from the Swedish National study on Ageing and Care in Kungsholmen (SNAC-K), Sweden. Standard magnetic resonance imaging (MRI) scans, vaMTA, and calculations of hippocampal volumes were performed in 544 subjects.                     

    Results Significant correlation (rs = −0.32, P < 0.001, sin; and rs = −0.26, P < 0.001, dx) was found between hippocampal volume measurements and vaMTA. In normal ageing, almost 95% of ≤66-year-olds had a medial temporal lobe atrophy (MTA) score ≤1, with possible scores ranging from 0 to 4. Subjects aged 72, 78, and 81 years scored ≤2, while the two oldest age groups had scores ≤3.                     

    Conclusion There was a highly significant correlation between volumetric measurements of the hippocampus and MTA scoring. In normal ageing, there is increasing MTA score. For non-demented elderly individuals ≤70 years, an MTA score of 0–1 may be considered normal, compared with MTA ≤2 for 70–80-years and MTA 3 for >80-year-old individuals.

  • 36.
    Chai, C M
    et al.
    University Hospital Malmö.
    Karlsson, J O G
    Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk farmakologi.
    Almen, Torsten
    University Hospital Malmö.
    Incidence of Ventricular Fibrillation during Left Coronary Arteriography in Pigs: Comparison of a Solution of the Nonionic Dimer Iodixanol with Solutions of Five Different Nonionic Monomers2008Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 49, nr 2, s. 150-156Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Solutions of iodine contrast media (CM) used for selective coronary arteriography (CA) should have minimal propensity to cause ventricular fibrillation (VF). Commonly used CM for CA are nonionic monomers or dimers.

    Purpose: To compare VF propensity of ready-to-use solutions of one nonionic dimer, iodixanol, and five nonionic monomers, iobitridol, iopamidol, iomeprol, iopromide, and ioversol.

    Material and Methods: Twenty milliliters of each CM was injected into the left coronary artery (LCA) through an inflated balloon catheter (0.5 ml/s) in 14 pigs; the longest period of injection was 40 s. If VF occurred before 40 s, the injection was stopped and the heart was defibrillated. After VF, there was a delay of 40 min before the next injection. Hemodynamic parameters and vector electrocardiography (VECG) were monitored. A CM with a lower frequency of VF and a longer period between start of injection and start of VF was considered to have a lower VF propensity.

    Results: Following 14 injections, each of the five nonionic monomers caused 14 VF, whereas iodixanol caused three VF (P<0.01). When VF occurred after iodixanol, it occurred later than after the other CM (P<0.001). Iodixanol caused less prolongation in QRS time (P<0.01) and QTc time (P<0.05) than the other CM. Prolongations in QRS and QTc times caused by CM parallel the VF propensities of the CM.

    Conclusion: Ready-to-use solutions of the dimer iodixanol have lower VF propensity than solutions of the five monomeric CM. This is related to the fact that the solutions of the dimer iodixanol have lower osmolality, higher viscosity, and higher concentrations of NaCl and CaCl2 than solutions of the five monomers.

  • 37.
    Ciray, Ipek
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Lindman, H
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Wanders, A
    Bergh, J
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on MR imaging of normal red bone marrow in breast cancer patients with focal bone metastases2003Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, nr 5, s. 472-484Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To investigate the effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on normal red bone marrow MR imaging in breast cancer patients with focal bone metastases.

    MATERIAL AND METHODS: Fifteen breast cancer patients who were examined before and after chemotherapy with T1-weighted-SE and long echo-time inversion-recovery turbo-spin-echo (long TE IR-TSE) sequences in the thoracolumbar spine and pelvis were retrospectively studied. Nine of them received G-CSF therapy after the administration of each chemotherapy course. Of these 9 patients, the MR follow-ups were performed during G-CSF in 4 patients and after G-CSF therapy in 5 patients. Six patients did not receive G-CSF. Signal intensity (SI) changes in normal bone marrow were evaluated visually in all patients and quantitatively in 13 patients.

    RESULTS: In all 4 patients investigated during G-CSF therapy a diffuse, homogeneous SI increase on long TE IR-TSE was observed visually and quantitatively in initially normal bone marrow. This change obscured some focal lesions in 2 patients. No such SI change was visible after G-CSF therapy (p = 0.008) or in patients not receiving G-CSF. On T1-weighted images an SI decrease was found both during and after G-CSF therapy, but an increase occurred in patients not receiving G-CSF.

    CONCLUSION: G-CSF-supported chemotherapy can induce diffuse SI changes in normal red bone marrow on MR imaging. On long TE IR-TSE, the changes are visible during G-CSF treatment and can lead to misinterpretations in the response evaluation of bone metastases to therapy.

  • 38.
    Ciray, Ipek
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Lindman, Henrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Bergh, J
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Early response of breast cancer bone metastases to chemotherapy evaluated with MR imaging2001Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, nr 2, s. 198-206Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    PURPOSE:

    To compare T1-weighted spin-echo and fat-suppressed long echo time inversion recovery turbo spin-echo (long TE IR-TSE) MR images in the evaluation of early response of breast cancer bone metastases to chemotherapy.

    MATERIAL AND METHODS:

    Eighteen breast cancer patients with known bone metastases were investigated prospectively by MR, using T1-weighted and long TE IR-TSE sequences on the sternum, spine, pelvis and proximal femora, before and after a median of 6 courses of chemotherapy. Therapeutic response evaluation with MR was based on change in tumor size assessed quantitatively by measuring all focal metastases, and change in pattern and signal intensity (SI) of the metastases, assessed visually. Combined response evaluation based on clinical findings, conventional radiography, and scintigraphy was used as reference.

    RESULTS:

    Progressive disease (2 patients) and no change (4 patients) were assessed equally well on both MR sequences. Long TE IR-TSE demonstrated partial response with higher accuracy than T1-weighted images, 58% (7/12 patients) vs. 17% (2/12 patients). In patients without progression there was an SI increase in or around the metastases in 6 patients on T1-weighted images and in 7 patients on long TE IR-TSE images.

    CONCLUSION:

    The long TE IR-TSE sequence demonstrated early partial response of breast cancer bone metastases to chemotherapy more accurately than the T1-weighted sequence.

  • 39.
    Ciray, Ipek
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Andréasson, I
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Edekling, T
    Hansen, J
    Bergh, J
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Evaluation of new sclerotic bone metastases in breast cancer patients during treatment2000Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 41, nr 2, s. 178-182Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE:

    According to the World Health Organization (WHO) criteria for response of bone metastases to therapy, new lesions indicate progressive disease. We intended to prove that a new sclerotic lesion on conventional radiography may also be a sign of a positive therapeutic response in a previously undetectable lytic metastasis.

    MATERIAL AND METHODS:

    In a previous placebo-controlled clinical trial of clodronate (Ostac) therapy, 139 breast cancer patients with bone metastases underwent both conventional radiography and bone scan every 6 months for 2 years with 99mTc before and during clodronate treatment. WHO criteria were applied for therapy response evaluation.

    RESULTS:

    In 24 patients, 52 new sclerotic lesions observed during therapy were selected for re-evaluation of conventional radiographs and bone scans. In 8 of the 24 patients, 17 of 52 new sclerotic lesions (33%) had showed positive uptake on previous bone scans. These lesions were possibly misinterpreted as new when applying WHO criteria.

    CONCLUSION:

    For better assessment of new sclerotic lesions during treatment, more sensitive techniques, e.g. bone scan, are needed as a complement to conventional radiography.

  • 40.
    Ciray, Ipek
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Åström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Sundström, Christer
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Molekylär och morfologisk patologi.
    Hagberg, Hans
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Assessment of suspected bone metastases: CT with and without clinical information compared to CT-guided bone biopsy1997Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 5, s. 890-895Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE:

    To evaluate the role of CT with and without clinical information as compared to CT-guided bone biopsy in the assessment of suspected bone metastases.

    MATERIAL AND METHODS:

    The study comprised 51 consecutive patients with suspected bone metastases who had undergone CT-guided bone biopsies with an eccentric drill system. CT of the targets, clinical information, and histopathology were scored separately as malignant, uncertain or benign. The results of CT alone and CT in combination with clinical information were compared to the results of histopathology.

    RESULTS:

    Histopathology diagnosed 45/51 lesions (88%), 23 as malignant and 22 as benign. CT correctly depicted 17 of these 23 malignant lesions. The remaining 6 malignant lesions were CT-scored as uncertain (n = 5) or benign (n = 1). CT correctly depicted only 3 of the 22 benign lesions. The remaining 19 benign lesions were CT-scored as malignant (n = 2) or uncertain (n = 17). When uncertain CT scores were combined with clinical scores, the true-positive and true-negative results for malignancy increased from 44% to 82%.

    CONCLUSION:

    In most cases, CT in combination with clinical information gives enough information about the nature-malignant or benign-of a skeletal lesion. In uncertain cases, diagnostic accuracy can be improved by means of CT-guided bone biopsy.

  • 41.
    Dahlman, Pär
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Jangland, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Segelsjö, Monika
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Optimization of computed tomography urography protocol, 1997 to 2008: effects on radiation dose2009Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 4, s. 446-454Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Since computed tomography (CT) urography began to replace excretory urography as the primary imaging technique in uroradiology, the collective radiation dose to the patients has increased. PURPOSE: To examine the changes in the CT urography protocol for investigating suspected urinary tract malignancy between the years 1997 and 2008, and how these changes have influenced the mean effective dose. MATERIAL AND METHODS: The study was based on 102 patients (mean age 66.1+/-14.8 years, range 31-89 years; 30 female, 72 male) divided into five groups (groups A-E) corresponding to the time points at which changes were made to the CT urography protocol. The mean effective doses were estimated using the ImPACT CT Patient Dosimetry Calculator. RESULTS: The number of scan phases at CT urography was reduced from four to three in 1999, resulting in a reduction of the mean effective dose from 29.9/22.5 (female [F]/male [M]) mSv (group A) to 26.1/18.9 (F/M) mSv (group B). In 2001, mAs settings were adapted to patient size, and the mean effective dose was reduced to 16.8/12.0 (F/M) mSv (group C). In 2005, scans were performed with a multidetector-row CT equipped with automatic tube current modulation in the x- and y-axis (CARE Dose). The effective mAs was also lowered in the unenhanced and excretory phase, yet the mean effective dose increased to 18.2/13.1 (F/M) mSv (group D), since the effective mAs had to be increased in the corticomedullary phase to maintain image quality. In 2008, as tube current modulation in the x-, y-, and z-axis was introduced (CARE Dose4D), the mean effective dose was reduced to 11.7/8.8 (F/M) mSv (group E). CONCLUSION: This study shows that the individual mean effective dose to patients undergoing CT urography has decreased by 60%, from 29.9/22.5 (F/M) mSv in 1997 to 11.7/8.8 (F/M) mSv in 2008.

  • 42.
    Dahlman, Pär
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Semenas, Egidijus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Brekkan, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Bergman, Antonina
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Detection and characterisation of renal lesions by multiphasic helical CT.2000Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Acta Radiol., Vol. 41, nr 4, s. 361-366Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: The fast helical CT technique allows examination of the kidneys during different phases of contrast medium enhancement. However, every additional phase increases the radiation dosage to the patients. We investigated the detection rate and characterisation of renal lesions during different phases and evaluated them separately, and considered the possibility of excluding phases without loss of important information.

    MATERIAL AND METHODS: Sixty patients who underwent contrast-enhanced multiphasic renal helical CT examination were included. Every CT phase was evaluated separately. The number of lesions and the characteristics of the lesions were noted and all lesions were viewed together.

    RESULTS: A total of 153 cysts and 17 solid lesions were detected. The largest and an equal number of cysts (142/143) was detected in the nephrographic and excretory phases. However, the nephrographic phase detected more cortical cysts and the excretory phase detected more sinus cysts. All solid lesions were detected in all phases. Renal parenchymal tumours were best characterised in the cortical phase and angiomyolipomas in the native phase.

    CONCLUSION: The cortical phase was best for characterisation of renal parenchymal tumours. The nephrographic and excretory phases were best in detecting and characterising renal cysts. The nephrographic phase was the phase giving the least diagnostic information.

  • 43.
    Dahlström, Nils
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Persson, Anders
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Albiin, Nils
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Brismar, Torkel
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Contrast-enhanced magnetic resonance cholangiography with Gd-BOPTA and Gd-EOB-DTPA in healthy subjects2007Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 4, s. 362-368Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE: To evaluate the biliary enhancement dynamics of the two gadolinium chelates Gd-BOPTA (MultiHance) and Gd-EOB-DTPA (Primovist) in normal healthy subjects. MATERIAL AND METHODS: Ten healthy volunteers were evaluated with both agents by magnetic resonance (MR) imaging at 1.5T using a breath-hold gradient-echo T1-weighted VIBE sequence. The relative signal intensity (SI) differences between the common hepatic duct (CHD) and liver parenchyma were measured before and 10, 20, 30, 40, 130, 240, and 300 min after contrast medium injection. RESULTS: Biliary enhancement was obvious 10 min post-injection for Gd-EOB-DTPA and was noted at 20 min for Gd-BOPTA. At 40 min delay, Gd-BOPTA reached its peak biliary enhancement, but at neither 30 nor 40 min delay was there any significant difference compared with that of Gd-EOB-DTPA. At later delays, the contrast between CHD and liver continued to increase for Gd-EOB-DTPA, whereas it decreased for Gd-BOPTA. CONCLUSION: The earlier onset and longer duration of a high contrast between CHD and liver for Gd-EOB-DTPA facilitates examination of hepatobiliary excretion. Therefore, Gd-EOB-DTPA may provide adequate hepatobiliary imaging within a shorter time span than Gd-BOPTA and facilitate scheduling at the MR unit. Further studies in patients are required to compare the imaging advantages of Gd-EOB-DTPA and Gd-BOPTA in clinical practice.

    Fulltekst (pdf)
    FULLTEXT01
  • 44.
    de Geer, Jakob
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Sandborg, Michael
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Persson, Anders
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    The efficacy of 2D, non-linear noise reduction filtering in cardiac imaging: a pilot study2011Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, nr 7, s. 716-722Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Computed tomography (CT) is becoming increasingly popular as a non-invasive method for visualizing the coronary arteries but patient radiation doses are still an issue. Postprocessing filters such as 2D adaptive non-linear filters might help to reduce the dose without loss of image quality. less thanbrgreater than less thanbrgreater thanPurpose: To investigate whether the use of a 2D, non-linear adaptive noise reduction filter can improve image quality in cardiac computed tomography angiography (CCTA). less thanbrgreater than less thanbrgreater thanMaterial and Methods: CCTA examinations were performed in 36 clinical patients on a dual source CT using two patient dose levels: maximum dose during diastole and reduced dose (20% of maximum dose) during systole. One full-dose and one reduced-dose image were selected from each of the examinations. The reduced-dose image was duplicated and one copy postprocessed using a 2D non-linear adaptive noise reduction filter, resulting in three images per patient. Image quality was assessed using visual grading with three criteria from the European guidelines for assessment of image quality and two additional criteria regarding the left main artery and the overall image quality. Also, the HU value and its standard deviation were measured in the ascending and descending aorta. Data were analyzed using Visual Grading Regression and paired t-test. less thanbrgreater than less thanbrgreater thanResult: For all five criteria, there was a significant (P andlt; 0.01 or better) improvement in perceived image quality when comparing postprocessed low-dose images with low-dose images without noise reduction. Comparing full dose images with postprocessed low-dose images resulted in a considerably larger, significant (P andlt; 0.001) difference. Also, there was a significant reduction of the standard deviation of the HU values in the ascending and descending aorta when comparing postprocessed low-dose images with low-dose images without postprocessing. less thanbrgreater than less thanbrgreater thanConclusion: Even with an 80% dose reduction, there was a significant improvement in the perceived image quality when using a 2D noise-reduction filter, though not approaching the quality of full-dose images. This indicates that cardiac CT examinations could benefit from noise-reducing postprocessing with 2D non-linear adaptive filters.

  • 45.
    De Geer, Jakob
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Sandstedt, Mårten
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Björkholm, Anders
    Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Alfredsson, Joakim
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Janzon, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Engvall, Jan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Persson, Anders
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Software-based on-site estimation of fractional flow reserve using standard coronary CT angiography data.2016Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, nr 10, s. 1186-1192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: The significance of a coronary stenosis can be determined by measuring the fractional flow reserve (FFR) during invasive coronary angiography. Recently, methods have been developed which claim to be able to estimate FFR using image data from standard coronary computed tomography angiography (CCTA) exams.

    PURPOSE: To evaluate the accuracy of non-invasively computed fractional flow reserve (cFFR) from CCTA.

    MATERIAL AND METHODS: A total of 23 vessels in 21 patients who had undergone both CCTA and invasive angiography with FFR measurement were evaluated using a cFFR software prototype. The cFFR results were compared to the invasively obtained FFR values. Correlation was calculated using Spearman's rank correlation, and agreement using intraclass correlation coefficient (ICC). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for significant stenosis (defined as both FFR ≤0.80 and FFR ≤0.75) were calculated.

    RESULTS: The mean cFFR value for the whole group was 0.81 and the corresponding mean invFFR value was 0.84. The cFFR sensitivity for significant stenosis (FFR ≤0.80/0.75) on a per-lesion basis was 0.83/0.80, specificity was 0.76/0.89, and accuracy 0.78/0.87. The positive predictive value was 0.56/0.67 and the negative predictive value was 0.93/0.94. The Spearman rank correlation coefficient was ρ = 0.77 (P < 0.001) and ICC = 0.73 (P < 0.001).

    CONCLUSION: This particular CCTA-based cFFR software prototype allows for a rapid, non-invasive on-site evaluation of cFFR. The results are encouraging and cFFR may in the future be of help in the triage to invasive coronary angiography.

  • 46.
    Dimitriou, Praxitelis
    et al.
    Department of Radiology, Örebro University Hospital , Örebro, Sweden.
    Kähäri, Anders
    Department of Clinical Physiology, Örebro University Hospital , Örebro, Sweden.
    Emilsson, Kent
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Clinical Physiology, Örebro University Hospital , Örebro, Sweden.
    Thunberg, Per
    Örebro universitet, Institutionen för hälsovetenskap och medicin. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden .
    Cardiovascular magnetic resonance imaging and transthoracic echocardiography in the assessment of stenotic aortic valve area: a comparative study2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 9, s. 995-1003Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Magnetic resonance (MR) imaging and echocardiography both allow assessment of aortic valve stenosis. In MR the aortic valve area (AvA) is measured using planimetry while in transthoracic echocardiography (TTE) AvA is usually calculated by applying the continuity equation.

    Purpose: To compare the measured stenotic aortic valve areas using five different MR-acquisition alternatives with the corresponding area values calculated by TTE.

    Material and Methods: The aortic valve was imaged in 14 patients, with diagnosed aortic valve stenosis, using balanced steady state free precession (bSSFP) gradient echo (GE) and phase contrast imaging (PC). Three adjacent slices were planned to encompass the aortic valve and the aortic valve area was measured using planimetry. The two sets of complex valued images generated by the PC sequence formed three kinds of images that could be used for aortic valve area measurements: the magnitude image (PC/Mag), the modulus (PCA/M), and phase difference (PCA/P) between the two complex images, respectively. The valve area from TTE was calculated using the continuity equation. A cut-off of <1.0 cm(2) was used as a criteria for severe stenosis.

    Results: The mean area differences between the different MR acquisitions and TTE method were -0.05 ± 0.37 cm(2) (GE), -0.18 ± 0.46 cm(2) (bSSFP), 0.27 ± 0.43 cm(2) (PC/Mag), 0.15 ± 0.32 cm(2) (PCA/P), and 0.26 ± 0.27 cm(2) (PCA/M). The valve area was significantly overestimated using PCA/M that, in turn, implied a significant underestimation of the aortic valve stenosis severity compared to the assessments using TTE.

    Conclusion: The smallest area valve difference between TTE and an MR-acquisition alternative is obtained with gradient echo images. The use of PCA/M leads to significant differences in planimetry measurements of the aortic valve orifice and the gradation of the stenosis severity compared to TTE.

  • 47.
    Dimopoulou, Angeliki
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Raland, Hans
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Wikström, Björn
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    MDCT angiography with 3D image reconstructions in the evaluation of failing arteriovenous fistulas and grafts in hemodialysis patients2011Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, nr 9, s. 935-942Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Arteriovenous fistulas and grafts are the methods of choice for vascular access in renal failure patients in need of hemodialysis. Their major complication, however, is stenosis, which might lead to thrombosis.

    Purpose: To demonstrate the usefulness of 16-MDCTA with 3D image reconstructions, in long-term hemodialysis patients with dysfunctional arteriovenous fistulas and grafts (AVF and AVG).

    Material and Methods: During a 17-month period, 31 patients with dysfunctional AVF and AVG (24 AVF and seven AVG) were examined with MDCTA with 3D image postprocessing. Parameters such as comprehension of the anatomy, quality of contrast enhancement, and pathological vascular changes were measured. DSA was then performed in 24 patients.

    Results: MDCTA illustrated the anatomy of the AVF/AVG and the entire vascular tree to the heart, in a detailed and comprehensive manner in 93.5% of the evaluated segments, and depicted pathology of AVF/AVG or pathology of the associated vasculature. MDCTA demonstrated a total of 38 significant stenoses in 25 patients. DSA verified 37 stenoses in 24 patients and demonstrated two additional stenoses. MDCTA had thus a sensitivity of 95%. All 24 patients were treated with percutaneous transluminal angioplasty (PTA) with good technical results.

    Conclusion: MDCTA with 3D reconstructions of dysfunctioning AVFs and AVGs in hemodialysis patients is an accurate and reliable diagnostic method helping customize future intervention.

  • 48.
    Djerf, K
    et al.
    Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Ortopedkliniken i Linköping.
    Edholm, P
    Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Ortopedkliniken i Linköping.
    Hedbrant, Johan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska fakulteten.
    A simplified roentgen stereophotogrammetric method. Analysis of small movements between the prosthetic stem and the femur after total hip replacement.1987Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 28, nr 5, s. 603-606Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simplified roentgen stereophotogrammetric method is described. It is based on the use of a 50 mm thick reference plate consisting of a carbon-fibre-reinforced polyester box. The patient is placed directly on this box, which makes the methods less cumbersome and more suitable for routine use. The method has been tested in a model experiment designed for detecting small movements between femur and prosthesis at an early stage after total hip replacement. The head and two hemispheres on the prosthesis and three small tantalum balls inserted in the femur serve as reference points. The model experiment now reported shows that the method has acceptable precision.

  • 49. Dormagen, Johann B.
    et al.
    Tötterman, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Ortopedi.
    Røise, Olav
    Sandvik, Leiv
    Kløw, Nils-E.
    Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients2010Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 51, nr 1, s. 107-16Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. PURPOSE: To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. MATERIAL AND METHODS: 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm(2). AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. RESULTS: Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm(2) posteriorly and >29 cm(2) anteriorly revealed specificity of 0.85 and 0.86, respectively. CONCLUSION: CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may contribute equally to effective assessment of injured arteries.

  • 50.
    Duvernoy, Olov
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Borowiec, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Thoraxkirurgi.
    Helmius, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Erikson, Uno
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Complications of percutaneous pericardiocentesis under fluoroscopic guidance1992Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 33, nr 4, s. 309-313Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Complications in 352 cases of fluoroscopy-guided percutaneous pericardiocentesis accomplished through an indwelling catheter were reviewed following surgery and non-surgery. Thirteen major complications were found, namely 3 cardiac perforations, 2 cardiac arrhythmias, 4 cases of arterial bleeding, 2 cases of pneumothorax in children, one infection, and one major vagal reaction. No significant difference in complications was found between pericardiocenteses for pericardial effusions after cardiac surgery (n = 208) and those for effusions of non-surgical (n = 144) origin. Fluoroscopy-guided pericardiocentesis by the subxiphoid approach with placement of an indwelling catheter is a safe method for achieving pericardial drainage in both surgical and non-surgical effusions. Accidental cardiac perforation with a fine needle is a minor complication as long as the needle is directed towards the anterior diaphragmatic border of the right ventricle and drainage is achieved with a reliable indwelling catheter.

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