Abstract
Purpose: To describe the imaging features of histologically defined early hepatocellular carcinoma (eHCC) on gadoxetate disodium-enhanced MRI (EOB-MRI) and diffusion-weighted imaging (DWI).Materials and Methods: We enrolled 173 surgically confirmed eHCCs in 119 patients examined by preoperative EOB-MRI and DWI between January 2006 and September 2017. The imaging features of preoperatively detected eHCCs were retrospectively analyzed by two radiologists. The clinical and imaging characteristics associated with false-negative detection were evaluated.Results: Of the 173 eHCCs, 118 (68%) in 78 patients were prospectively reported on preoperative EOB-MRI. After retrospective review, 17 eHCCs in 13 patients were additionally detected, with a per-lesion detection sensitivity of 78% (135/173). Thus, the imaging features of 135 eHCCs in 91 patients were analyzed. Most eHCCs exhibited hepatobiliary hypointensity (90%, 122/135). Arterial phase hyperenhancement, washout, and capsule appearance were seen in 68 (50%), 79 (59%), and 11 (8%) detected lesions, respectively. Diffusion restriction and fatty change were noted in 30 (22%) and 39 (29%) lesions, respectively; most eHCCs exhibited T1 and T2 isointensity (80 [59%] and 89 [66%], respectively). False-negative detection was associated with small lesion size (< 1 cm), history of HCC treatment (odds ratio, 0.34 [95% confidence interval, 0.13-0.92]), number of HCC lesions (≥ 2; odds ratio, 0.08 [0.01-0.66]), and poor functional liver imaging score (< 4; odds ratio, 0.13 [0.04-0.51]).Conclusions: Histologically defined eHCCs typically appear as hepatobiliary phase hypointensity. Detection sensitivity of eHCC may be affected by lesion size, history of HCC treatment, number of HCCs, and hepatobiliary enhancement.
Publisher
The Korean Society of Abdominal Radiology