Clinical implication of small (<20 mm) enhancing hepatic nodules observed only during three-dimensional gadobenate dimeglumine-enhanced hepatic arterial-phase MRI of the hepatitis B virus-induced mild cirrhosis

Objective: The purpose of this study is to determine the clinical implication of small (<20 mm) enhancing hepatic nodules observed only at three-dimensional gadobenate dimeglumine-enhanced hepatic arterial-phase magnetic resonance imaging (MRI) of the hepatitis B virus-induced mild cirrhosis. Materials and methods: Study population included 75 patients (58 men and 17 women; age range, 45-74 years) who had 100 arterial-only enhancing hepatic nodules occult during portal- and equilibrium-phase MRI. All patients had mild liver cirrhosis (Child class A, n=69; B, n=6) associated with viral hepatitis B. Two reviewers analyzed the MRIs in consensus regarding the size, shape, and signal intensity of nodules on the T1- and T2-weighted images. Results: Of these 100 lesions, 78 and 22 proved to be hepatocellular carcinomas (HCCs) (size range, 0.6-1.9 cm; mean, 1.2 cm) and benign lesions (size range, 0.6-1.9 cm; mean, 1.0 cm), respectively. Most of the lesions (n=98) were oval or round shaped. Thirty-four HCCs were hypointense and/or hyperintense on the T1- and T2-weighted images, respectively. There was a trend toward an increased suspicion of HCC for arterial-only enhancing lesions occult on the portal- and equilibrium-phase and on T1- and T2-weighted MRI (n=44/66 for HCC vs. n=22/66 for benign lesions). Conclusions: Small arterial-only enhancing nodules occult on the portal- and equilibrium-phase images as well as on the T1- and T2-weighted images are more likely to be HCC than nonneoplastic hypervascular benign lesions in patients with hepatitis B-induced mild cirrhosis.