Prognostic Implications of CT- and MRI-Based LI-RADS Category M Features in Intrahepatic Cholangiocarcinoma: An Intraindividual Comparison.

objectiveLiver Imaging Reporting and Data System category M (LR-M) is associated with a poor prognosis in intrahepatic cholangiocarcinoma (iCCA). However, the prognostic value of individual LR-M features across imaging modalities remains unclear. We aimed to determine, through intraindividual comparisons, whether the prognostic value of individual LR-M features differs between CT and MRI in patients with iCCA at risk for hepatocellular carcinoma. MATERIALS AND

methodsThis retrospective study included consecutive patients with cirrhosis or chronic hepatitis B who underwent curative-intent resection for iCCA and preoperative multiphasic CT and MRI between 2010 and 2019. CT and MRI images were reviewed in separate sessions ≥4 weeks apart. Cox proportional hazards regression analyses with and without adjustment for LI-RADS categorization (non-LR-M vs. single-modality LR-M or dual-modality LR-M) were performed to evaluate the associations of CT- and MRI-based targetoid and non-targetoid LR-M features and other variables with recurrence-free survival (RFS) and overall survival (OS).

resultsA cohort of 122 patients (mean age, 57.9 ± 10.4 years) was included. MRI demonstrated significantly higher frequencies than CT for targetoid (84.4% vs. 73.8%,

conclusionThe prognostic implications of LR-M features in iCCA vary by imaging modality and feature type. CT-based targetoid and MRI-based non-targetoid features were associated with poorer survival, and the associations between MRI-based non-targetoid features and survival remained significant after adjustment for LI-RADS categorization.