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PurposeThe purpose of this study was to assess the influence of iodine concentration on diagnostic efficacy in multi-detector-row computed tomography (MDCT) angiography of the abdominal aorta and abdominal arteries.MethodsIRB approval and informed consent were obtained. In this double-blind trial, patients were randomised to undergo MDCT angiography of the abdominal arteries during administration of iobitridol (350 mgI/ml) or iomeprol (400 mgI/ml). Each centre applied its own technique for delivery of contrast medium, regardless of iodine concentration. Diagnostic efficacy, image quality, visualisation of the arterial wall and arterial enhancement were evaluated. A total of 153 patients received iobitridol and 154 received iomeprol.ResultsThe ability to reach a diagnosis was “satisfactory” to “totally satisfactory” in 152 (99.3%) and 153 (99.4%) patients respectively. Image quality was rated as being “good” to “excellent” in 94.7 and 94.8% segments respectively. Similar results were observed for image quality of arterial walls (84.3 vs. 83.2%). The mean relative changes in arterial enhancement between baseline and arterial phase images showed no statistically significant differences.ConclusionThis study demonstrated the non-inferiority of the 350 versus 400 mgI/ml iodine concentration, in terms of diagnostic efficacy, in abdominal MDCT angiography. It also confirmed the high robustness and reliability of this technique across multi-national practices.

Determination of the overlay CT number with DECT enables to stratify metastases with stable, increasing or decreasing iodine uptake over time with -in our collective- typical lesion size change patterns. Investigation of a larger patient cohort, comparison to histology, alternate imaging biomarkers and correlatrion to long-term response will further clarify the significance of these findings for monitoring targeted therapies in GIST.

Segmentation is an essential task in medical image analysis. For example measuring tumor growth in consecutive CT scans based on the volume of the tumor requires a good segmentation. Since manual segmentation takes too much time in clinical routine automatic segmentation algorithms are typically used. However there are always cases where an automatic segmentation fails to provide an acceptable segmentation for example due to low contrast, noise or structures of the same density lying close to the lesion. These erroneous segmentation masks need to be manually corrected. We present a novel method for fast three-dimensional local manual correction of segmentation masks. The user needs to draw only one partial contour which describes the lesion's actual border. This two-dimensional interaction is then transferred into 3D using a live-wire based extrapolation of the contour that is given by the user in one slice. Seed points calculated from this contour are moved to adjacent slices by a block matching algorithm. The seed points are then connected by a live-wire algorithm which ensures a segmentation that passes along the border of the lesion. After this extrapolation a morphological postprocessing is performed to generate a coherent and smooth surface corresponding to the user drawn contour as well as to the initial segmentation. An evaluation on 108 lesions by six radiologists has shown that our method is both intuitive and fast. Using our method the radiologists were able to correct 96.3% of lesion segmentations rated as insufficient to acceptable ones in a median time of 44s

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Zerebrale Ischämien gehören mit einer Häufigkeit von 7 % (Caselli RJ et al. Neurology 1988; 38: 352 -359) zu den atypischen und seltenen Komplikationen einer floriden Riesenzellarteriitis (RZA). Wird die zu einer zerebralen Ischämie führende RZA nicht rechtzeitig erkannt, drohen in engem zeitlichen Zusammenhang weitere Komplikationen bis hin zu lebensbedrohlichen Hirninfarkten und beidseitiger Erblindung, die durch eine rechtzeitige Steroidtherapie vermieden werden können. Die RZA ist eine systemische Vaskulitis der großen und mittelgroßen Arterien, die alle Schichten der Arterienwand befällt. Charakteristisch sind segmentale Stenosen, vor allem Abb. 1 Bereits demarkierte beidseitige PICATeilinfarkte in der nativen kraniellen CT. Abb. 2 Abgangsnaher Verschluss der Aa. vertebrales (Pfeile in a). Langstreckig fehlende Kontrastierung, exemplarisch gezeigt in Höhe des 4. Halswirbels (Pfeile in b). Beide Gefäße werden erst im distalen V4-Segment wieder angefärbt (Pfeile in c). Die Karotisbifurkationen, die bds. geringe arteriosklerotische Veränderungen aufweisen, sind mit Sternen markiert b. Auffällige Wandverdickung des Aortenbogens d und der supraaortalen Gefäßabgänge e in der CT-Angiografie (Pfeile).The Interesting Case 492 Hittinger M et al. Hirninfarkt im hinteren … Fortschr Röntgenstr 2015; 187: 492-494 · DOI http://dx.