Journal Article

Targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement: diagnostic value for differentiating HCC from other primary liver carcinomas

Tsung, Allan, Borhani, Amir A., Furlan, Alessandro, Cannella, Roberto, Ludwig, Daniel R., Fraum, Tyler J., Fowler, Kathryn J.

2021

Overview

Objectives To evaluate targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement as potential new LI-RADS features for differentiating hepatocellular carcinoma (HCC) from other non-HCC primary liver carcinomas (PLCs). Methods This IRB-approved, retrospective study was performed at two liver transplant centers. The final population included 375 patients with pathologically proven lesions imaged between 2007 and 2017 with contrast-enhanced CT or MRI. The cohort consisted of 165 intrahepatic cholangiocarcinomas and 74 combined hepatocellular-cholangiocarcinomas, with the addition of 136 HCCs for control. Two abdominal radiologists (R1; R2) independently reviewed the imaging studies (112 CT; 263 MRI) and recorded the presence of targetoid appearance on T2-weighted images and features of tumor vascular involvement including encasement, narrowing, tethering, occlusion, and obliteration. The sensitivity and specificity of each feature were calculated for the diagnosis of non-HCC PLCs. Cohen’s kappa ( k ) test was used to assess inter-reader agreement. Results The sensitivity of targetoid appearance on T2-weighted images for the diagnosis of non-HCC PLCs was 27.5% and 32.6% (R1 and R2) and the specificity was 98.2% and 97.3% (R1 and R2). Among the features of tumor vascular involvement, those providing the highest sensitivity for non-HCC PLCs were vascular encasement (R1: 34.3%; R2: 37.2%) and obliteration (R1: 25.5%; R2: 29.7%). The highest specificity for non-HCC PLCs was provided by tethering (R1: 100%; R2: 97.1%) and occlusion (R1: 99.3%; R2: 99.3%). The inter-reader agreement was moderate to substantial ( k = 0.48–0.77). Conclusions Targetoid appearance on T2-weighted images and features of tumor vascular involvement demonstrated high specificity for non-HCC malignancy. Key Points • Targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement have high specificity (92–100%) for the diagnosis of non-HCC PLCs, regardless of the presence of liver risk factors. • In the subset of patients with risk factors for HCC, the sensitivity of signs of tumor vascular involvement decreases for both readers (1.7–20.3%), while the specificity increases reaching values higher than 94.2%. • The inter-reader agreement is substantial for targetoid appearance on T2-weighted images (k = 0.74) and moderate to substantial for signs of tumor vascular involvement (k = 0.48–0.77).

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Carcinoma / Computed tomography / Diagnosis / Diagnostic Radiology / Hepatobiliary-Pancreas / Hepatocellular carcinoma / Imaging / Internal Medicine / Interventional Radiology / Liver / Liver cancer / Liver transplantation / Magnetic resonance imaging / Malignancy / Medical diagnosis / Medical imaging / Medicine / Medicine & Public Health / Neuroradiology / Occlusion / Programmable logic controllers / Radiology / Risk analysis / Risk factors / Tethering / Tumors / Ultrasound