MR features of small hepatocellular carcinoma in normal, fibrotic, and cirrhotic livers: a comparative study.

PURPOSE

The objective of this study is to compare MR imaging features of small hepatocellular carcinoma (HCC) (≤ 2 cm) in normal, fibrotic, and cirrhotic liver.

METHODS

A total of 215 patients with 235 pathologically proven sHCC were retrospectively analyzed. Patients were classified into three groups according to the patients' liver condition: patients with normal liver (F0, group 1), fibrosis without cirrhosis (F1-3, group 2), and cirrhosis (F4, group 3). The morphological and MR signal features on T1, T2-weighted, dynamic enhanced, and diffusion-weighted imaging were evaluated and compared.

RESULTS

There were 10, 38, and 167 patients in group 1, 2, and 3, respectively. Patients with normal liver were older than those with fibrosis or cirrhosis (P = 0.0086), and tumors in the normal liver were larger than those in the fibrotic or cirrhotic liver (P = 0.0407). No statistical differences were found among groups in signals on T2-weighted images (P = 0.163), signals on each phase after contrast (P = 0.269, 0.893, and 0.259, respectively), enhancement patterns (P = 0.753), ADC values (P = 0.760), as well as the presence of capsule-like enhancement (P = 0.953), mosaic pattern (P = 0.572), fat content (P = 0.222), iron sparing (P = 1.000), hemorrhage (P = 0.181), and venous invasion (P = 0.175). Both signal-to-noise ratios (SNR) (χ (2) = 2.045, P = 0.132) and lesion-to-liver contrast-to-noise ratios (CNR) (χ (2) = 0.438, P = 0.646) were not different as well. But confusing features of iso/hypointensity on T2-weighted imaging (n = 11, 6.0%) and progressive enhancement pattern (n = 2, 1.1%) were exclusively found in the cirrhosis background, and hypovascular tumors with iso/hypointensity on arterial phase were only seen in the fibrosis (n = 5, 11.9%) and cirrhosis groups (n = 10, 5.5%).

CONCLUSION

MR features of sHCC were similar among patients with normal, fibrotic, and cirrhotic livers.