Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis

Abstract

ObjectiveTo validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis.Materials and MethodsThe Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40–85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm2 at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis.ResultsThe mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10-3 mm2/sec and 0.92 ± 0.25 × 10-3 mm2/sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10-3 mm2/sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9–98.9%) and a sensitivity of 22.2% (95% CI: 6.4–47.6%), respectively.ConclusionDue to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently.

The role of dynamic and diffusion weighted magnetic resonance imaging in differentiating malignant and benign portal vein thrombosis

“…In this study and in a few of literature studies, no statistically significant differences were demonstrated between different b values with malignant and benign PVT ADC values due to reasons mentioned above (25). Beside this, particularly in malignant thrombotic tissues, high signal intensities are observed in DW-MRI, due to high cell density and secondary to prevented diffusion.…”

Contrast-enhanced ultrasound for the characterization of portal vein thrombosis vs tumor-in-vein in HCC patients: a systematic review and meta-analysis

“…Besides, published studies have reported high diagnostic accuracy (up to 95%) for differentiating malignant component from benign PVT by gadoxetic acid-enhanced MR imaging [36]. Susceptibility-weighted MRI was superior to diffusionweighted MR imaging in distinguishing the malignant component in portal vein with a high diagnostic capability (AUC, 0.989; sensitivity, 95%; specificity, 95.5%) [37][38][39][40].…”

The Diagnostic Performance of Liver MRI without Intravenous Contrast for Detecting Hepatocellular Carcinoma: A Case-Controlled Feasibility Study

“…Improved MRI performance due to multichannel surface receiver coils, parallel imaging techniques, fat suppression schemes, DWI, adoption of the hepatocyte specific contrast agents and multiple arterial phases has improved the performance of liver MRI for lesion detection and liver function evaluation ( 20 21 22 23 24 25 26 27 ). However, as mentioned above, an enhanced MRI has some limitations and the focus of this study was on a non-contrast MRI as a potential HCC surveillance tool.…”