Assessment of cancer cell differentiation in small hepatocellular carcinoma by computed tomography and magnetic resonance imaging

Aim: To study whether cancer cell differentiation in small hepatocellular carcinoma (HCC) can be assessed by computed tomography (CT) and magnetic resonance (MR) imaging. Methods: We retrospectively evaluated the relationship between cancer cell differentiation in 127 HCC 3 cm or less in diameter (113 patients) and CT and MR images. Images were reviewed in a consensus conference by three authors (SA, TY, and ME). Histopathological diagnosis of HCC was made from liver specimens obtained by sonographically guided biopsy. Results: The degree of histological differentiation of cancer cells was significantly different between HCC that were isodense with liver parenchyma in both artery‐dominant and equilibrium phases in contrast‐enhanced CT and tumors that were hyperdense in the artery‐dominant phase and iso‐ or hypodense in the equilibrium phase (P = 0.0054), as well as tumors that were iso‐ or hypodense artery‐dominant and hypodense equilibrium (P = 0.0002). Histological differentiation of lesions that were hyperintense in T1‐weighted images and hypointense in T2‐weighted images differed significantly from those with the opposite MR characteristics (P = 0.0122). In T1‐weighted fat‐suppression images and T2‐weighted images, respectively, the degree of histological differentiation was significant between the hypointense/hyperintense and the hyperintense/hypointense patterns (P