A semiautomatic lesion segmentation and histogram analysis approach can provide a significant reduction in interobserver variability for DCE MR imaging measurements of K(trans) when compared with manual ROI methods, whereas intraobserver reproducibility is improved to some extent.

A considerable variability for DCE MR imaging pharmacokinetic parameters (K(trans), k(ep), v(e), iAUGC) was found among commercially available perfusion analysis solutions. Therefore, clinical comparability across perfusion analysis solutions is currently not warranted. Agreement on a postprocessing standard is paramount prior to establishing DCE MR imaging as a widely incorporated biomarker.

• Patients with diminished breath-holding capacities present a major challenge in abdominal MRI. • A free-breathing sequence for hepatobiliary-phase MRI can improve image quality. • Further advances are needed to reduce acquisition time of the free-breathing gradient-echo sequence.

The purpose of this study was to test the hypothesis that with improved technology, the presence of abscess in a postoperative fluid collection may be prospectively made. This is an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective review of computed tomography (CT)-guided intra-abdominal fluid collection drainages. The diagnostic CT scans of 95 consecutive patients performed on 16- and 64-multidetector CT (MDCT) were reviewed by four readers with varying abdominal imaging expertise. Readers were asked to determine fluid content, to document whether infection was present, and to rate reader confidence for infection. A fifth radiologist reviewed the collections for imaging characteristics. The gold standard for presence of infection was microbiological Gram stain and culture. The logistic regression model showed that both fluid collections containing gas or high attenuation fluid (average CT density 20 or greater Hounsfield units) are significant predictors of infection ( P = 0.001). The average sensitivity over the four readers for determining presence of infection was 83.4 per cent and specificity was 39.3 per cent. Even in the era of MDCT, the ability to predict whether or not a fluid collection is infected or not, based on imaging findings alone, is limited. Presence of gas is a strong indicator of infection, but no imaging finding is characteristic of a sterile fluid collection.