Which is the best MRI marker of malignancy for atypical cirrhotic nodules: Hypointensity in hepatobiliary phase alone or combined with other features? Classification after Gd‐EOB‐DTPA administration

Abstract Purpose: To investigate whether the malignancy of atypical nodules in cirrhosis can be identified at gadoxetic‐acid‐disodium(Gd‐EOB‐DTPA)‐MRI by their hypointensity in the hepatobiliary(HB)‐phase alone or combined with any other MR imaging features. Materials and Methods: One hundred eleven atypical nodules detected in 77 consecutive Gd‐EOB‐DTPA‐MRIs were divided, based on arterial‐phase behavior, into: Class I , isovascular (n = 82), and Class II , hypervascular without portal/delayed washout (n = 29). The two classes were further grouped based on HB‐phase intensity (A/B/C hypo/iso/hyperintensity). Portal/venous/equilibrium‐phase behavior and T2w features were also collected. Histology was the gold standard. Per‐nodule sensitivity, specificity, negative and positive predictive values (NPV/PPV), and diagnostic accuracy were calculated for HB‐phase hypointensity alone, and combined with vascular patterns and T2w hyperintensity. Results: Histology detected 60 benign and 51 malignant/premalignant nodules [10 overt hepatocellular carcinomas (HCCs) and 41 high‐grade dysplastic nodules (HGDN)/early HCC]. Class IA contained 31 (94%) malignancies, IB one (3%), and IC only benign lesions. Class IIA had 100% malignancies, IIB three (37.5%) and IIC only two (28.5%). HB‐phase hypointensity alone (Classes I–IIA) had 88% sensitivity, 91% NPV, and 93% diagnostic accuracy, superior ( P < 0.05, P < 0.006, and P < 0.05, respectively) to any other MR imaging feature alone or combined. Conclusion: In atypical cirrhotic nodules, HB‐phase hypointensity by itself is the strongest marker of malignancy. J. Magn. Reson. Imaging 2012;36:648–657. © 2012 Wiley Periodicals, Inc.