Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma: Diagnostic Accuracy of Gadoxetic Acid-enhanced MR Imaging.

Purpose To assess the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging in the evaluation of portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC). Materials and Methods This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. A total of 366 patients with HCC who underwent gadoxetic acid-enhanced MR imaging between January 2007 and May 2013, including 134 with malignant PVT, 49 with benign PVT, and 183 without PVT matched for age and sex, comprised our study population. PVTs were complete in 125 patients and partial in 58 and were located in a major portal vein (n = 159) or segmental portal vein (n = 24). Two radiologists independently reviewed the MR images and assessed the sensitivity, specificity, and accuracy in the detection and characterization of PVT according to location (major vs segmental) and type (complete vs partial). The Fisher exact or χ(2) test was used to evaluate sensitivity difference between the subsets. Results Gadoxetic acid-enhanced MR imaging showed good sensitivity (reviewer 1, 84% [154 of 183 patients]; reviewer 2, 70% [129 of 183 patients]) and high specificity (reviewer 1, 89% [163 of 183 patients]; reviewer 2, 96% [176 of 183 patients]) in the detection of PVT. Diagnostic accuracy for differentiating malignant PVT from benign PVT was high (reviewer 1, 92% [141 of 154 patients]; reviewer 2, 95% [122 of 129 patients]). However, there was slightly lower sensitivity for detecting segmental PVT compared with that of major PVT in the malignant PVT group (reviewer 1, 95% [104 of 110 patients] vs 88% [21 of 24 patients]; reviewer 2, 82% [90 of 110 patients] vs 79% [19 of 24 patients]; P = .203 and .775 for reviewers 1 and 2, respectively). Conclusion Gadoxetic acid-enhanced MR imaging provided good diagnostic performance in the detection of PVT and the differentiation of malignant from benign PVT in patients with HCC. However, caution is needed when evaluating potential candidates for curative treatment because of the low sensitivity for segmental PVT in the malignant PVT group. (©) RSNA, 2016 Online supplemental material is available for this article.