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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.
    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.

  • 3.
    Björkman, Ann-Sofi
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    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 medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Karolinska Inst, Sweden.
    Diagnostic accuracy of dual-energy CT for detection of bone marrow lesions in the subacutely injured knee with MRI as reference method2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, artikkel-id UNSP 0284185119877343Artikkel 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.

  • 4.
    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.

  • 5.
    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.

  • 6.
    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.

  • 7.
    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.

  • 8.
    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.

  • 9.
    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.

  • 10.
    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.

  • 11.
    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.

  • 12.
    Edholm, Paul
    et al.
    n/a.
    Granlund, Gösta
    Linköpings universitet, Institutionen för systemteknik, Bildbehandling. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Petersson, C.
    n/a.
    Ectomography: A New Radiographic Method for Reproducing a Selected Slice of Varying Thickness1980Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 21, nr 4, s. 433-442Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mathematical basis is described of a new radiographic method by which an arbitrarily thick layer of the patient may be reconstructed. The reconstruction is performed from at least 60 images of the volume under examination. Each of these images, which have to be in digital form, is subjected to a special filtration process of its spatial frequencies. The combination of all the images will form the resulting image of the layer--the ectomogram. The method has been analysed and tested in experiments simulated with a computer.

  • 13. Eklöf, H
    et al.
    Smedby, Örjan
    Department of Radiology, University Hospital, Uppsala, Sweden.
    Ljungman, C
    Karacagil, S
    Bergqvist, D
    Ahlström, H
    2D inflow MR angiography in severe chronic leg ischemia1998Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, nr 6, s. 663-668Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The agreement between MRA and XRA was good in the calf but questionable in the foot.

  • 14.
    Engellau, Lena
    et al.
    Department of Radiology, Lund University Hospital, Lund, Sweden.
    Albrechtsson, U.
    Department of Radiology, Lund University Hospital, Lund, Sweden.
    Dahlström, Nils
    Department of Radiology, Hudiksvall Hospital, Hudiksvall Sweden.
    Norgren, L.
    Department of Vascular Diseases, Lund University, Malmo University Hospital, Malmo, Sweden.
    Persson, Anders
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Larsson, E.-M.
    Department of Radiology, Lund University Hospital, Lund, Sweden.
    Measurements before endovascular repair of abdominal aortic aneurysms: MR imaging with MRA vs. angiography and CT2003Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, nr 2, s. 177-184Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: 1) To compare measurements obtained with MR imaging (MRI)/contrast-enhanced MR angiography (CE MRA) with measurements obtained with angiography (DSA) and CT, for stent-graft sizing of abdominal aortic aneurysms (AAA). 2) To compare MRA measurements obtained with the two post processing techniques MIP (maximum intensity projection) and VRT (3D volume rendering technique).

    Material and Methods: The prospective study included 20 consecutive patients with AAA identified by DSA and CT as suitable for endovascular repair. For the study, MRI/CE MRA was performed. Five measurement variables for stent-graft sizing were chosen. Comparisons were made between MRI/CE MRA, DSA and CT, and between observers. Comparisons were also made between MIP and VRT.

    Results: Significantly shorter lengths were obtained with MRA-MIP than with DSA. Three out of six diameter measurements were significantly smaller on MRI/CE MRA than on DSA and CT. No significant differences were found between the observers. One diameter measurement was significantly smaller on MIP than on VRT, while the other measurements showed no significant differences.

    Conclusion: The length measurements obtained with MRA-MIP were probably more correct than those with DSA. For more reliable diameter measurements with CE MRA, improvements of the technique, including VRT reconstructions and a standardized determination of the vessel boundaries, are needed.

  • 15.
    Engström, Maria
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Karlsson, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Crone, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Tekniska högskolan.
    Ragnehed, Mattias
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Antepohl, Wolfram
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Rehabiliteringsmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Rekonstruktionscentrum, Rehabiliteringsmedicinska kliniken US.
    Landtblom, Anne-Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Neurologiska kliniken. Östergötlands Läns Landsting, Närsjukvården i västra Östergötland, Medicinska specialistkliniken .
    Lundberg, Peter
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Clinical fMRI of language function in aphasic patients: Reading paradigm successful, while word generation paradigm fails2010Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 51, nr 6, s. 679-686Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: In fMRI examinations, it is very important to select appropriate paradigms assessing the brain function of interest. In addition, the patients ability to perform the required cognitive tasks during fMRI must be taken into account. Purpose: To evaluate two language paradigms, word generation and sentence reading for their usefulness in examinations of aphasic patients and to make suggestions for improvements of clinical fMRI. Material and Methods: Five patients with aphasia after stroke or trauma sequelae were examined by fMRI. The patients language ability was screened by neurolinguistic tests and elementary pre-fMRI language tests. Results: The sentence-reading paradigm succeeded to elicit adequate language-related activation in perilesional areas whereas the word generation paradigm failed. These findings were consistent with results on the behavioral tests in that all patients showed very poor performance in phonemic fluency, but scored well above mean at a reading comprehension task. Conclusion: The sentence-reading paradigm is appropriate to assess language function in this patient group, while the word-generation paradigm seems to be inadequate. In addition, it is crucial to use elementary pre-fMRI language tests to guide the fMRI paradigm decision.

  • 16.
    Fransson, Sven Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Editorial Material: The annoying pulmonary nodule on CT2014Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, nr 4, s. 387-388Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    n/a

  • 17.
    Fransson, Sven Göran
    Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper.
    Editorial Material: Tuberculosis: a medical evergreen in ACTA RADIOLOGICA, vol 56, issue 5, pp 515-5162015Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 56, nr 5, s. 515-516Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    n/a

  • 18.
    Fransson, Sven Göran
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiologi. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Persliden, Jan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik.
    Patient radiation exposure during coronary angiography and intervention2000Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 41, nr 2, s. 142-144Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To prospectively register fluoroscopic and cine times in a random fashion, and to measure patient radiation exposure from routine coronary angiography and coronary balloon angioplasty. We also evaluated an optional dose reduction system used during interventions. Material and Methods: The incident radiation to the patient was measured as kerma area product (KAP) in Gycm2, obtained from an ionisation chamber mounted on the undercouch tube during 65 coronary angiography procedures and another 53 percutaneous transluminal coronary angioplasties (including 29 stent procedures), mostly directly following complete coronary angiography. Results and Conclusion: The values from coronary angiography were comparable to other reports with a mean fluoroscopic time of 4.4 min and a mean KAP value of 62.6 Gycm2. The corresponding figures from coronary balloon angioplasty without stenting were lower than otherwise reported, with 8.2 min and 47.9 Gycm2, respectively. The use of coronary stents did prolong the mean fluoroscopic time (10.5 min) but did not significantly enhance the patient mean radiation dose (51.4 Gycm2). The dose reduction technique resulted in a significant KAP value reduction of 57%. In conclusion, with regard to radiation exposure, coronary angiography and balloon angioplasty are considered safe procedures.

  • 19.
    Fransson, Sven-Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    Aids to Radiological Differential Diagnosis2009Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 6, s. 701-701Artikkel, omtale (Fagfellevurdert)
  • 20.
    Fransson, Sven-Göran
    Department of Radiology, Medical School, University of Linköping, Sweden.
    Note: Pacemaker Wires -  Difference in performance between AMBER and conventional chest radiography1993Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 34, nr 4, s. 419-421Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Evaluation of pacemaker wires were performed by comparing Advanced Multiple Beam Equalization Radiography (AMBER) with conventional chest radiography. The scanning equalization technique of the AMBER unit makes it superior to conventional technique in the depiction of different structures in the mediastinum or in the pleural sinuses. So far motion artifacts have not been considered clinically important. The longer exposure time, however, may impair the assessment of pacemaker wires. The motion artifact described may not only make adequate evaluation impossible but may even give a false impression of a lead fracture. The difference between the two systems was significant.

  • 21.
    Fransson, Sven-Göran
    Department of Diagnostic Radiology, University Hospital, Linköping, Sweden.
    Wrist Arthrography1993Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 34, nr 2, s. 111-116Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The ligaments of the proximal row of carpal bones and the triangular fibrocartilage (TFC) strongly influence the function and stability of the wrist. Injury to the ligaments may result in chronic wrist pain or instability. Wrist arthrography is valuable in the investigation of such damage when surgical intervention is considered and plain radiography is unrewarding. There are also several technical modifications of the standard radiocarpal arthrography available. Owing to the possibility of congenital perforations and degenerative changes in these ligaments the arthrographic findings should be related to the clinical signs and the age of the patient. CT has less diagnostic importance in this respect while MR imaging is an alternative and may become the method of choice. Both these methods have great potential in the evaluation of soft tissues of the wrist other than the TFC.

  • 22.
    Fransson, Sven-Göran
    et al.
    Department of Thoracic Radiology, University Hospital, Linköping, Sweden.
    Stenport, G.
    Department of Thoracic Radiology, University Hospital, Linköping.
    Andersson, M.
    Nycomed AB, Lidingö, Sweden.
    Immediate and late adverse reactions in coronary angiography. A comparison between iodixanol and ioxaglate1996Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 37, nr 2, s. 218-222Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose and Methods: In 120 patients in a double-blind, randomized, parallel study, iodixanol (Visipaque), a nonionic dimer isotonic with blood, was compared with ioxaglate (Hexabrix), an ionic low-osmolar dimer, in coronary angiography regarding early and late adverse reactions. Haemodynamic and electrophysiologic parameters were also analyzed. Results: Visipaque resulted in significantly fewer early adverse contrast medium related reactions (p less than 0.05). Visipaque also demonstrated significantly fewer effects on electrophysiologic parameters. Both contrast media reduced systolic and diastolic blood pressures at the Ist injection in the left coronary artery. Late adverse reactions were unusual with both contrast media and occurred only as urticaria with a frequency of 1.7%, which is lower than reported in i.v. studies. One serious adverse reaction, a myocardial infarction in a male patient with severe cardiovascular disease, occurred in the Visipaque group. This event was considered to be procedure- and disease-related rather than related to the type of contrast medium used. Conclusion: We found Visipaque safe for coronary angiography, causing fewer early adverse reactions than Hexabrix and also fewer effects on electrophysiologic parameters. Late adverse reactions seemed to be unusual with intra-arterial administration of contrast media.

  • 23.
    Fransson, Sven-Göran
    et al.
    Linköpings universitet. Östergötlands Läns Landsting.
    Sökjer, H.
    Linköpings universitet. Östergötlands Läns Landsting.
    Johansson, K. E.
    Linköpings universitet. Östergötlands Läns Landsting.
    Tibbling, L.
    Linköpings universitet. Östergötlands Läns Landsting.
    Radiologic Diagnosis of Gastro-Oesophageal Reflux - Comparison of barium and low-density contrast medium1987Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 28, nr 3, s. 295-298Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It has been proposed that the high density of ordinary barium suspensions may complicate the radiologic diagnosis of gastro-oesophageal reflux. For this reason P-contrast was developed (Ferring AB); a contrast medium with the same density as water (1 g/cm3). A comparison of P-contrast and barium (Mixobar Ventrikel 400 mg/ml) was performed in 82 patients. All patients were examined with both contrast media and the findings were compared with those at reflux test at manometry, endoscopy and 24-hour pH monitoring. Another 40 patients and 15 symptom-free controls were examined with two different amounts of barium, 100 ml and 200 ml, to study if the radiologic diagnosis of reflux varied with the volume of contrast medium administered. P-contrast was found to have no advantages over barium for the diagnosis of gastro-oesophageal reflux. The outcome of the radiologic examination was not influenced by the different volumes of barium used.

  • 24.
    Fransson, Sven-Göran
    et al.
    Linköpings universitet. Östergötlands Läns Landsting.
    Sökjer, H.
    Linköpings universitet. Östergötlands Läns Landsting.
    Johansson, K. E.
    Linköpings universitet. Östergötlands Läns Landsting.
    Tibbling, L.
    Linköpings universitet. Östergötlands Läns Landsting.
    Radiologic diagnosis of gastro-oesophageal reflux by means of graded abdominal compression1988Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 29, nr 1, s. 45-48Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of the study was to ascertain whether abdominal compression by a standardized technique increases the reliability of the radiologic diagnosis of gastro-oesophageal reflux. Eighty-eight patients were examined by means of a manometric reflux test, 24-hour measurements of pH and endoscopy. The radiologic examination was performed with and without graded abdominal compression, the patient at the same time turning from side to side. When abdominal compression was included the result of the radiologic examination was positive in 31 patients. In the absence of abdominal compression reflux was detected in 11 of these patients. In one patient reflux was detected only without compression. All these 31 patients had one more test positive and in 27 at least 2 more tests were positive. Another 21 patients had reflux disease as indicated by at least 2 of the 3 other tests. The compression technique seems to yield no false positive responses, and proved to be significantly more reliable than examinations without compression.

  • 25.
    Fransson, Sven-Göran
    et al.
    Department of Diagnostic Radiology, Linköping University Hospital, Linköping, Sweden.
    Sökjer, H.
    Östergötlands Läns Landsting.
    Johansson, K. E.
    Östergötlands Läns Landsting.
    Tibbling, L.
    Östergötlands Läns Landsting.
    Radiologic findings after fundoplication compared with a pH reflux test and symptoms1986Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 27, nr 1, s. 33-39Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In a follow-up after fundoplication, 61 patients underwent a double contrast examination of the stomach and a radiologic examination to detect any gastro-oesophageal reflux. The radiologic findings were compared with pH reflux test and symptoms. Gastro-oesophageal reflux was found in 7 patients at radiologic examination. None of these patients had an adequate fundoplication at a double contrast examination of the stomach and all had symptoms indicating reflux. Recurrence of gastro-oesophageal reflux may be shown at the radiologic examination and predicted by the morphologic appearances at the double contrast examination.

  • 26.
    Fransson, Sven-Göran
    et al.
    Department of Diagnostic Radiology, Regionsjukhuset, Linköping, Sweden .
    Sökjer, H.
    Linköpings universitet. Östergötlands Läns Landsting.
    Johansson, K.-E.
    Linköpings universitet. Östergötlands Läns Landsting.
    Tibbling, L.
    Linköpings universitet. Östergötlands Läns Landsting.
    Radiologic Diagnosis of Gastro-Oesophageal Reflux1989Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 30, nr 2, s. 187-192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In 149 patients, a standardized radiologic method for the detection of gastro-oesophageal reflux was applied and compared with the results obtained at endoscopy and by a manometric reflux test. Radiologic reflux was recorded in 53 patients, of whom 25 had reflux without abdominal compression and 51 with compression. At least one of the other two types of examination disclosed pathologic conditions in all but 2 of 53 patients. Oesophagitis was significantly more severe among the patients with reflux observed at radiography. The presence of hiatal incompetence with reflux only to the hiatal hernia but not to the oesophagus was not a strong indicator of gastro-oesophageal reflux disease. Hiatal hernia was present in a significantly larger number of the patients with reflux at radiography than in those without reflux. Increased width of the hiatus gave stronger evidence for reflux disease than in patients with a normal hiatus. Thus, the width of the hiatus also had a bearing on the diagnosis of gastro-oesophageal reflux disease.

  • 27.
    Frones, S.
    et al.
    Frønes, S..
    Stoen, R.
    Støen, R..
    Gregersen, M.
    Gregersen, M..
    Refsum, H.
    Refsum, H..
    Krane, J.
    Krane, J..
    Karlsson, Jan Olof
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa.
    The iodinated radiographic contrast medium iohexol mimics the vasodilator effect seen with small increases in extracellular K+ in the isolated rabbit central ear artery2006Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, nr 7, s. 692-698Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To investigate whether iodinated radiographic contrast media (IRCM) mimic the hyperpolarizing and vasodilator effects of K + by comparing the vasodilator effect of a transient rise in extracellular K + with that of the IRCM iohexol. Material and Methods: Immersed rabbit central ear arterial rings with and without endothelium and pre-contracted with phenylephrine (PE) were used to investigate the dependency of the endothelium in K + -induced vasodilatation. Perfused rabbit central ear arteries, pre-contracted with PE, were used to study the effects of bolus administrations of the IRCM iohexol or KCl on arterial tone under conditions that mimic those employed during clinical arteriography. Results: A small rise in K + caused an endothelium-independent and ouabain-sensitive relaxation of PE-constricted rabbit central ear artery rings. The relaxation was not changed in the presence of barium. The IRCM iohexol and KCl, injected as boluses into perfused PE-constricted rabbit ear arteries, caused transient decreases in perfusion pressure. Iohexol- and K + -induced pressure decreases were significantly reduced in the presence of 10M ouabain alone or in combination with 30M barium. Neither iohexol- nor K + -induced pressure decrease was significantly changed in the presence of barium alone compared to controls. Conclusion: The vasodilator effect of IRCM mimics the vasodilator effect seen upon small increase in extracellular K + . Under the experimental conditions employed in the present study, a considerable part of the IRCM-induced vasodilatation appears to be due to activation of Na + /K + -ATPase in the smooth muscle cells. © 2006 Taylor and Francis.

  • 28.
    Geijer, H
    Orebro Univ Hosp, Dept Radiol, SE-70185 Orebro, Sweden Linkoping Univ, Fac Hlth Sci, Dept Med & Care, SE-58185 Linkoping, Sweden.
    Radiation dose and image quality in diagnostic radiology2002Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Radiation dose and image quality in diagnostic radiology. Optimization of the dose-image quality relationship with clinical experience from scoliosis radiography, coronary intervention and a flat-panel detector.

  • 29.
    Geijer, H
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiologi.
    Radiation dose and image quality in diagnostic radiology2002Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 427Artikkel i tidsskrift (Fagfellevurdert)
  • 30. Henriksson, L
    et al.
    Sundin, A
    Smedby, Örjan
    Department of Diagnostic Radiology, Akademiska Sjukhuset, Uppsala.
    Albrektsson, P
    Assessment of congestive heart failure in chest radiographs. Observer performance with two common film-screen systems.1990Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 31, nr 5, s. 469-471Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of observer variations and film-screen quality on the diagnosis of congestive heart failure based on chest radiographs was studied in 27 patients. For each patient, two films were exposed, one with the Kodak Lanex Medium system and one with the Agfa MR 400 system. The films were presented to three observers who assessed the presence of congestive heart failure on a three-graded scale. The results showed no significant difference between the two systems but large systematic differences between the observers. There were also differences between the two ratings by the same observer that could not be explained by the film-screen factor. It is concluded that the choice between these two systems is of little importance in view of the interobserver and intraobserver variability that can exist within the same department.

  • 31. Jangland, L
    et al.
    Sanner, E
    Persliden, Jan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Dose reduction in computed tomography by individualized scan protocols2004Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 45, nr 3, s. 301-307Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To find a method of adjusting the mAs-value in relation to the size of the patient undergoing computed tomography (CT) examination as a means of minimizing the radiation dose to the patient. Material and Methods: A correction factor to be applied on the tube charge for each patient was calculated using two mathematical methods. This approach was tested on 4 Perspex phantoms of different sizes and geometries. Noise was measured in the images with and without use of the correction factors. Retrospectively, correction factors were calculated for 12 CT examinations of the abdomen and the dose reduction was estimated for these patient studies. Results: The variations in noise measured in the images of the different phantoms were dramatically reduced by both methods. The retrospectively performed patient study showed that the largest correction factor was 7 times greater than the smallest, which means that a dose reduction factor of 7 is possible in the extreme case. Conclusion: Our proposed methods of adjusting the applied tube charge (mAs-value) in relation to the size of the patient can be used on the vast majority of CT systems. The potential for dose reduction is great, especially for small patients.

  • 32.
    Kalra, Mannudeep
    et al.
    Massachusetts General Hospital, Boston, MA, USA .
    Quick, Petter
    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.
    Singh, Sarabjeet
    Massachusetts General Hospital, Boston, MA, USA .
    Sandborg, Michael
    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.
    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, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Whole spine CT for evaluation of scoliosis in children: feasibility of sub-milliSievert scanning protocol2013Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 54, nr 2, s. 226-230Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Optimization of CT radiation dose is important for children due to their higher risk of radiation-induced adverse effects. Anatomical structures with high inherent contrast, such as bones can be imaged at very low radiation doses by optimizing scan parameters.                    

    Purpose To assess feasibility of sub-milliSievert whole spine CT scanning protocol for evaluation of scoliosis in children.                    

    Material and Methods With approval of the ethical board, we performed whole spine CT for evaluation of scoliosis in 22 children (age range, 3–18 years; mean age, 13 years; 13 girls, 9 boys) on a 128-slice dual source multidetector-row CT scanner. Lowest possible quality reference mAs value (image quality factor for xy-z automatic exposure control or xyz-AEC, CARE Dose 4D) was selected on a per patient basis. Remaining parameters were held constant at 3.0:1 pitch, 128 × 0.6 mm detector collimation, 115.2 mm table feed per gantry rotation, 100 kVp, and 1 and 3 mm reconstructed sections. Average mAs, projected estimated dose savings with AEC, computed tomography dose index volume (CTDI vol), and dose length product (DLP) were recorded. Artifacts were graded on a four-point scale (1, no artifacts; 4, severe artifacts). Ability to identify vertebral and pedicular contours, and measure pedicular width and degree of vertebral rotation was graded on a three-point scale (1, unacceptable; 3, excellent).       

    Results All CT examinations were deemed as reliable for identifying vertebral and pedicular contours as well as for measuring pedicular width (5.9 ± 1.6 mm) and degree of vertebral rotation (28.7 ± 23.4°). Mean objective image noise and signal to noise ratio (SNR) were 57.5 ± 21.5 and 4.7 ± 2.3, respectively. With a mean quality reference mAs of 13, the scanner employed an average actual effective mAs of 10 ± 3.8 (range, 6–18 mAs) with an estimated radiation dose saving of 43.5 ± 16.3% with xyz-AEC compared with fixed mAs. The mean CTDI, DLP, and estimated effective doses were 0.4 ± 0.1 mGy (0.2–0.7 mGy), 21 ± 10 mGy.cm (8–41 mGy.cm), and 0.3 ± 0.1 mSv (0.12–0.64 mSv), respectively.                    

    Conclusion Radiation dose for whole spine CT for evaluation of scoliosis in children can be minimized to less than one-third of a milliSievert while maintaining diagnostic image quality.

  • 33.
    Karlsson, J
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Farmakologi.
    Brurok, K
    Trondheim.
    Eriksen, M
    Oslo.
    Towart, R
    USA.
    Toft, K
    Oslo.
    Moen, O
    Oslo.
    Engebretsen, B
    Oslo.
    Jynge, P
    Trondheim.
    Refsum, H
    Oslo.
    Cardioprotective effects of the MR contrast agent MnDPDP and its metabolite MnPLED upon reperfusion of the ischemic porcine myocardium2001Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, nr 6, s. 540-547Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To evaluate whether manganese dipyridoxyl diphosphate (MnDPDP) or its metabolite manganese dipyridoxyl ethyldiamine (MnPLED) reduces post-ischemic myocardial injury. Material and Methods: Left anterior descending artery (LAD) in anesthetized pigs was occluded (30 min) followed by reperfusion (120 min) during hemodynamic monitoring and infarct assessment. Three ╡mol/kg MnDPDP, 1 ╡mol/kg MnPLED (or a mixture of both) or saline was injected i.v. 10 min before reperfusion followed by infusion of either 3 ╡mol/kg/h MnDPDP, 1 ╡mol/kg/h MnPLED (or a mixture of both) or saline. The plasma concentrations of MnDPDP, MnPLED and other metabolites (e.g., ZnDPDP and ZnPLED) were analyzed. Results: Femoral blood flow was reduced by 60% during early reperfusion in controls, whereas only 23 and 31% reductions were seen in animals treated with MnDPDP and MnPLED During that time, +LV/dP and -LV/dP (maximum rate of left ventricular isovolumic contraction and relaxation, respectively), systolic pressure and diastolic pressure fell significantly less in animals treated with MnDPDP or MnPLED. Three out of 5 control animals experienced ventricular fibrillation (VF) during reperfusion, whereas VF was not seen in any of the pigs treated with MnPLED or/and MnDPDP. The infarct sizes in saline- and MnPLED-treated animals were 39▒6 and 16▒5%, respectively, of the occluded areas. MnDPDP did not reduce the infarct size. A mixture of MnDPDP and MnPLED significantly reduced infarct size (10▒4%). When reperfusion started and throughout reperfusion, almost all injected MnDPDP was present as Zn-metabolites. Conclusion: MnPLED seems to reduce reperfusion-induced cardiac dysfunction and infarct size in pigs. MnDPDP does not reduce infarct size in the pig, probably because of the rapid exchange of Mn2+ for Zn2+ taking place in the pig.

  • 34.
    Kataria, Bharti
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Medicinska fakulteten. Östergötlands Läns Landsting, Närsjukvården i östra Östergötland.
    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.
    Patient dose and image quality in low-dose abdominal CT: a comparison between iterative reconstruction and filtered back projection2013Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 54, nr 5, s. 540-548Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background In computed tomography (CT), there is increasing concern for potential CT radiation hazards. Several raw-data-based iterative reconstruction techniques attempt to facilitate low-dose imaging without compromising image quality, which raises the question whether these techniques may allow further dose reduction.

    Purpose To compare image quality of iterative reconstruction and filtered back projection in low-dose abdominal CT and study the potential for further dose reduction.

    Material and Methods Forty-five patients underwent CT of the abdomen twice: with standard low-dose technique and with 30% reduced dose, using both iterative reconstruction and filtered back projection. Four radiologists made pair-wise image quality assessment using five visual criteria. Visual grading regression (VGR) and weighted kappa (κ w) were used to analyze the data.

    Results There were significant effects of log(mAs) (P <0.001) and reconstruction algorithm (P <0.01) on all image quality criteria with an estimated potential dose reduction of 5–9%. Inter-observer agreement ranged from 70% to 91% and κ w from −0.01 to 0.57.

    Conclusion An iterative reconstruction algorithm improved image quality in abdominal CT, but the estimated dose reduction was rather small. The full potential of the algorithm remains unclear.

  • 35.
    Larsson, C
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Anestesiologi. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Davidsson, L
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Avdelningen för radiologi US.
    Lundin, P
    Gustafsson, G
    Vegfors, M
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Anestesiologi. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Respiratory monitoring during MR imaging. the clinical value of a new fibre-optical monitor.1999Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 40, s. 33-36Artikkel i tidsskrift (Fagfellevurdert)
  • 36.
    Liden, Mats
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. University of Örebro, Sweden.
    Thunberg, Per
    University of Örebro, Sweden.
    Broxvall, Mathias
    University of Örebro, Sweden.
    Geijer, Hakan
    University of Örebro, Sweden.
    Two- and three-dimensional CT measurements of urinary calculi length and width: a comparative study2015Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 56, nr 4, s. 487-492Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The standard imaging procedure for a patient presenting with renal colic is unenhanced computed tomography (CT). The CT measured size has a close correlation to the estimated prognosis for spontaneous passage of a ureteral calculus. Size estimations of urinary calculi in CT images are still based on two-dimensional (2D) reformats. Purpose: To develop and validate a calculus oriented three-dimensional (3D) method for measuring the length and width of urinary calculi and to compare the calculus oriented measurements of the length and width with corresponding 2D measurements obtained in axial and coronal reformats. Material and Methods: Fifty unenhanced CT examinations demonstrating urinary calculi were included. A 3D symmetric segmentation algorithm was validated against reader size estimations. The calculus oriented size from the segmentation was then compared to the estimated size in axial and coronal 2D reformats. Results: The validation showed 0.1 +/- 0.7mm agreement against reference measure. There was a 0.4mm median bias for 3D estimated calculus length compared to 2D (P less than 0.001), but no significant bias for 3D width compared to 2D. Conclusion: The length of a calculus in axial and coronal reformats becomes underestimated compared to 3D if its orientation is not aligned to the image planes. Future studies aiming to correlate calculus size with patient outcome should use a calculus oriented size estimation.

  • 37.
    Liss, Per
    et al.
    Uppsala universitet, Institutionen för onkologi, radiologi och klinisk immunologi.
    Aukland, Knut
    Carlsson, Per-Ola
    Institutionen för medicinsk cellbiologi.
    Palm, Fredrik
    Institutionen för medicinsk cellbiologi.
    Hansell, Peter
    Institutionen för medicinsk cellbiologi.
    Influence of iothalamate on renal medullary perfusion and oxygenation in the rat.2005Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, nr 8, s. 823-9Artikkel i tidsskrift (Annet vitenskapelig)
  • 38.
    Lundin, Margareta
    et al.
    Department of Radiology, Örebro University Hospital, 701 85 Örebro, Sweden.
    Lidén, M
    Department of Radiology, Örebro University Hospital, 701 85 Örebro, Sweden.
    Magnusson, A,
    Department of Radiology, Örebro University Hospital, 701 85 Örebro, Sweden.
    Abdulilah Mohammed, A.
    Department of Radiology, Örebro University Hospital, 701 85 Örebro, Sweden.
    Geijer, Håkan
    Department of Radiology, Örebro University Hospital, 701 85 Örebro, Sweden.
    Andersson, Torbjörn
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet.
    Persson, Anders
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Virtual non-contrast dual-energy CT compared to single-energy CT of the urinary tract: a prospective study2012Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 6, s. 689-694Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Dual-energy computed tomography (DECT) has been shown to be useful for subtracting bone or calcium in CT angiography and gives an opportunity to produce a virtual non-contrast-enhanced (VNC) image from a series where contrast agents have been given intravenously. High noise levels and low resolution have previously limited the diagnostic value of the VNC images created with the first generation of DECT. With the recent introduction of a second generation of DECT, there is a possibility of obtaining VNC images with better image quality at hopefully lower radiation dose compared to the previous generation.

    Purpose: The aim of this study is to compare the image quality of the single-energy series to a VNC series obtained with a two generations of DECT scanners. CT of the urinary tract was used as a model.

    Material and Methods: Thirty patients referred for evaluation of haematuria were examined with an older system (Somatom Definition) and another 30 patients with a new generation (Somatom Definition Flash). One single-energy series was obtained before and one dual-energy series after administration of intravenous contrast media. We created a VNC series from the contrast-enhanced images. Images were assessed concerning image quality with a visual grading scale evaluation of the VNC series with the single-energy series as gold standard.

    Results: The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, OR range 11.5-67.3 for the Definition and OR 2.1-2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than Definition.

    Conclusions: Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images. However the difference is smaller with the new compared to the older system.

  • 39.
    Nilsson, Sven
    et al.
    Uppsala.
    Bergstrand, Lott
    Stockholm.
    Erikson, Uno
    Uppsala.
    Johansson, Jan
    Stockholm.
    Smedby, Örjan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Avdelningen för radiologi US.
    Walldius, Göran
    Astra-Zeneca .
    Allergic reactions at repeat femoral angiography with ioxaglate.2001Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, s. 608-611Artikkel i tidsskrift (Fagfellevurdert)
  • 40. Nilsson, Sven
    et al.
    Bergstrand, Lott
    Erikson, Uno
    Johansson, Jan
    Smedby, Örjan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Avdelningen för radiologi US.
    Walldius, Göran
    Allergic reactions at repeat femoral angiography with ioxaglate2000Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, s. 608-611Artikkel i tidsskrift (Fagfellevurdert)
  • 41.
    Persliden, J.
    et al.
    Department of Radiation Physics, Linköping University, Linköping.
    Fransson, Sven-Göran
    Department of Thoracic Radiology, Faculty of Health Sciences, Linköping University, Linköping.
    AMBER chest radiography and patient dose measurements1995Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, nr 6, s. 641-643Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PURPOSE:

    Improved chest imaging has been reported with the usage of AMBER (advanced multiple-beam equalization radiography) equipment but with a higher patient radiation dose compared with conventional chest radiography. Most studies, however, describe dose measurements from phantoms. This study presents a comparison of radiation dose measurements in 57 patients for p.a. projections from an AMBER unit with and without an extra Cu filtration and from a formerly used conventional Siemens chest stand.

    MATERIAL AND METHODS:

    Dose measurements were performed with thermoluminescence dosimetry. Entrance surface doses were recorded from 5 dosimeters, placed on the patient's back. Four were placed over the upper and lower lung fields, respectively, and 1 over the mediastinal area. The dose values were then compared with the values obtained from the conventional chest stand and from the measurements with the extra filtration on the AMBER system.

    RESULTS:

    The mean entrance dose for the mediastinal area was 0.25 mSv (range 0.15-0.49). With the extra Cu filtration it was 0.16 mSv (0.07-0.29). For the lung fields the values were 0.19 mSv (0.07-0.44) and 0.10 mSv (0.02-0.31), respectively. For the conventional chest stand the entrance dose to the patient was 0.23 mSv.

    CONCLUSION:

    AMBER entrance surface doses for the p.a. projection without extra Cu filtration were comparable to the doses obtained with the formerly conventional Siemens chest stand and were well within European recommendations. With extra Cu filtration the AMBER entrance surface doses were reduced by a factor of almost 2.

  • 42.
    Persliden, Jan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Sandborg, Michael
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Conversion factors between the energy imparted to the patient and air collision kerma integrated over beam area in paediatric radiology1993Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 34, s. 92-98Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 43.
    Persson, Anders
    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.
    Brismar, Torkel
    Karolinska Institutet, CLINTEC, Röntgenavdelningen, Karolinska Universitetssjukhuset Huddinge.
    Lundström, Claes
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Visuell informationsteknologi och applikationer. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    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.
    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.
    Othberg, Fredrik
    Linköpings universitet, Institutionen för medicinsk teknik, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Standardized volume rendering for magnetic resonance angiography measurements in the abdominal aorta2006Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, nr 2, s. 172-178Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To compare three methods for standardizing volume rendering technique (VRT) protocols by studying aortic diameter measurements in magnetic resonance angiography (MRA) datasets.

    Material and Methods: Datasets from 20 patients previously examined with gadolinium-enhanced MRA and with digital subtraction angiography (DSA) for abdominal aortic aneurysm were retrospectively evaluated by three independent readers. The MRA datasets were viewed using VRT with three different standardized transfer functions: the percentile method (Pc-VRT), the maximum-likelihood method (ML-VRT), and the partial range histogram method (PRH-VRT). The aortic diameters obtained with these three methods were compared with freely chosen VRT parameters (F-VRT) and with maximum intensity projection (MIP) concerning inter-reader variability and agreement with the reference method DSA.

    Results: F-VRT parameters and PRH-VRT gave significantly higher diameter values than DSA, whereas Pc-VRT gave significantly lower values than DSA. The highest interobserver variability was found for F-VRT parameters and MIP, and the lowest for Pc-VRT and PRH-VRT. All standardized VRT methods were significantly superior to both MIP and F-VRT in this respect. The agreement with DSA was best for PRH-VRT, which was the only method with a mean error below 1 mm and which also had the narrowest limits of agreement (95% of cases between 2.1 mm below and 3.1 mm above DSA).

    Conclusion: All the standardized VRT methods compare favorably with MIP and VRT with freely selected parameters as regards interobserver variability. The partial range histogram method, although systematically overestimating vessel diameters, gives results closest to those of DSA.

  • 44.
    Persson, Anders
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet.
    Dahlström, Nils
    Department of Radiology, Hudiksvall Hospital, Sweden.
    Engellau, Lena
    Department of Radiology, Lund University, Malmö University Hospital.
    Larsson, Elna-Marie
    Department of Radiology, Lund University Hospital.
    Brismar, Torkel B.
    Center for Surgical Sciences, Division of Radiology, Karolinska Institutet, Stockholm.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping.
    Volume rendering compared with maximum intensity projection for magnetic resonance angiography measurements of the abdominal aorta2004Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 45, nr 4, s. 453-459Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To compare the volume rendering technique (VRT) with maximum intensity projection (MIP) for aortic diameter measurements in MR angiography (MRA) data sets.

    Material and Methods: Existing contrast-enhanced 3-dimensional MRA and digital subtraction angiography (DSA) data sets from 20 patients were analyzed. In each MRA data set, two aortic diameters were measured using MIP and VRT. Agreement with DSA measurements, dependence on rendering parameters, and interobserver agreement were assessed.

    Results: Diameters measured on MIP with fixed parameters showed no significant difference compared with DSA and with freely selected parameters a slight overestimation relative to DSA. Diameters measured on VRT were larger than on DSA. For both MIP and VRT, the measurements depended on the chosen parameters. The error relative to DSA was larger for VRT than for MIP with fixed parameters but not with freely chosen parameters. Interobserver agreement did not differ significantly.

    Conclusions: VRT is not suitable for diameter measurements of the abdominal aorta with fixed parameter settings but may be useful with user-selected settings.

  • 45.
    Persson, Anders
    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, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Lindblom, Maria
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Jackowski, Christian
    Institute of Legal Medicine, University of Zürich, Schweiz.
    A state-of-the-art pipeline for postmortem CT and MRI visualization: from data acquisition to interactive image interpretation at autopsy2011Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, nr 5, s. 522-536Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The importance of autopsy procedures leading to the establishment of the cause of death is well-known. A recent addition to the autopsy work flow is the possibility of conducting postmortem imaging, in its 3D version also called virtual autopsy (VA), using multidetector computed tomography (MDCT) or magnetic resonance imagining (MRI) data from scans of cadavers displayed with direct volume rendering (DVR) 3D techniques. The use of the data and their workflow are presented. Data acquisition was performed and high quality data-sets with submillimeter precision were acquired. New data acquisition techniques such as dualenergy CT (DECT) and quantitative MRI, then were implemented and provided additional information. Particular findings hardly visualized in conventional autopsy can rather easy be seen at the full body CT, such as air distribution, e.g. pneumothorax, pneumopericardium, air embolism, and wound channels. MRI shows natural deaths such as myocardial infarctions. Interactive visualization of these 3D data-sets can provide valuable insight into the corpses and enables non-invasive diagnostic procedures. In postmortem CT imaging, not being limited by a patient depending radiation dose limit the data-sets can, however, be generated with such a high resolution that they become difficult to handle in today’s archive retrieval and interactive visualization systems, specifically in the case of full body scans. To take full advantage of these new technologies the postmortem workflow needs to be tailored to the demands and opportunities that the new technologies allow.

  • 46. Radecka, E
    et al.
    Brekkan, E
    Juhlin, Claes
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Kirurgi. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Kirurgiska kliniken i Östergötland med verksamhet i Linköping, Norrköping och Motala.
    Nilsson, L
    Sundin, A
    Magnusson, A
    An unusual case of tumor thrombus in the inferior vena cava. A case report.2003Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, s. 160-161Artikkel i tidsskrift (Fagfellevurdert)
  • 47.
    Rossitti, Sandro
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Neurokirurgi. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US.
    Endovascular coiling of intracranial aneurysms using bioactive coils: A single-center study2007Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 5, s. 565-576Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Some degree of recanalization is reported in up to one-third of intracranial aneurysms treated with endovascular coiling. A technical development potentially effective in avoiding recanalization is the Matrix Detachable Coil (MDC), which is covered with a biodegradable polymeric material that enhances intra-aneurysmal clot organization and fibrosis. Purpose: To report the initial clinical experience of MDC for endovascular aneurysm coiling in a single-center, single-operator, and well-defined population setting. Material and Methods: 118 aneurysms in 104 patients (73 with subarachnoid hemorrhage, SAH) were embolized with MDC alone (n=52) or combined with bare platinum coils (n=66). Results: Initial aneurysm obliteration was class 1 (complete obliteration) in 45 aneurysms (38.1%), class 2 (residual neck) in 44 (37.3%), and class 3 (residual aneurysm) in 29 (24.6%). Procedure-related morbidity was 4.8%, and mortality 0.96%. Clinical follow-up of 61 patients with SAH (mean 5.9 months, range 1-17 months) showed good outcome (Glasgow Outcome Scale, GOS 4-5) in 39 (63.9%), and poor outcome or death (GOS 1-3) in 22 (36.1%). Imaging follow-up of 73 aneurysms (average 6.5 months, range 1-17 months) showed class 1 in 47 (64.4%), class 2 in 18 (24.7%), and class 3 in eight (10.9%). Recanalization occurred in 11 aneurysms (15%), of which four (5.5%) required re-treatment. Conclusion: This study confirms that aneurysm coiling with MDC is feasible, effective, and safe. © 2007 Taylor and Francis.

  • 48.
    Rossitti, Sandro
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Neurokirurgi. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US.
    Preoperative embolization of lower-falx meningiomas with ethylene vinyl alcohol copolymer: Technical and anatomical aspects2007Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 3, s. 321-326Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To report the feasibility of using ethylene vinyl alcohol copolymer (EVAC) for embolization of lower-falx meningiomas. Material and Methods: Three patients were treated. The procedures were done under general anesthesia. A terminal branch of the middle cerebral artery in the proximity of the tumor was catheterized as near as possible or into the pre-falcine arterial anastomotic network around the superior sagittal sinus, and embolization with EVAC was performed with a standard injection technique. Results: This technique resulted in filling of the tumor-supplying dural arteries including all collaterals from both sides, filling of the dural territory of the tumor circulation, and some obliteration of the tumor's pial supply. On later operation, the tumors could be removed from the inside out with minimal brain retraction. Conclusion: Effective preoperative embolization of lower-falx meningiomas using EVAC is feasible. This technique has a sound anatomical basis, and it can be used with benefit even in falx meningiomas with predominantly pial vascular supply. © 2007 Taylor & Francis.

  • 49.
    Sandstedt, Mårten
    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. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    De Geer, Jakob
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Henriksson, Lilian
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Region Östergötland, Diagnostikcentrum, Röntgenkliniken i Linköping.
    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.
    Janzon, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Persson, Anders
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. 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.
    Long-term prognostic value of coronary computed tomography angiography in chest pain patients.2019Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, nr 1, s. 45-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Coronary computed tomography angiography (CCTA) is increasingly used to detect coronary artery disease (CAD), but long-term follow-up studies are still scarce. Purpose To evaluate the prognostic value of CCTA in patients with suspected CAD. Material and Methods A total of 1205 consecutive CCTA patients with chest pain were classified as normal coronary arteries, non-obstructive CAD, or obstructive CAD. The primary outcome was major adverse cardiac event (MACE), defined as a composite outcome including cardiac death, myocardial infarction, unstable angina pectoris, or late revascularization (after >90 days). Results Over 7.5 years follow-up (median = 3.1 years), Kaplan-Meier estimates demonstrated a MACE in 1.0%, 4.6%, and 20.7% in normal coronary arteries, non-obstructive CAD, and obstructive CAD, respectively. Log rank test for pairwise comparisons showed significant differences between non-obstructive CAD and normal coronary arteries ( P = 0.023) and between obstructive CAD and normal coronary arteries ( P < 0.001). In a multivariable analysis, adjusting for classical risk factors, non-obstructive CAD and obstructive CAD were independent predictors of MACE, with hazard ratios (HR) of 3.22 ( P = 0.041) and 25.18 ( P < 0.001), respectively. Conclusion Patients with normal coronary arteries have excellent long-term prognosis, but the risk for MACE increases with non-obstructive and obstructive CAD. Both non-obstructive and obstructive CAD are independently associated with future ischemic events.

  • 50. Sjoholm, B
    et al.
    Geijer, H
    Persliden, Jan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract2005Inngår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, nr 6, s. 657-661Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department. Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector. Results: A dose reduction from 41.8 Gycm(2) to 31.5 Gycm(2) was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm(2) was achieved using the flat panel detector. Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible.

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