Cirrhosis or chronic hepatitis:: Evaluation of small (≤2-cm) early-enhancing hepatic lesions with serial contrast-enhanced dynamic MR imaging

PURPOSE. To evaluate the frequency and clinical importance of small (less than or equal to2 cm) early-enhancing hepatic lesions in cirrhotic liver disease with serial multiphasic contrast material-enhanced dynamic magnetic resonance (MR) imaging. MATERIALS AND METHODS: The study population included 208 patients with cirrhosis (n = 162) or chronic hepatitis (n = 46) who underwent dynamic contrast-enhanced MR imaging at least twice during the clinical course, with at least a 12-month interval between the initial and latest MR examinations, Initial images were evaluated for the presence and shape of small (less than or equal to2 cm) early-enhancing hepatic lesions at arterial-phase contrast-enhanced MR imaging. If a small early-enhancing lesion was seen on the initial image, the latest follow-up image was reviewed to assess the serial changes in the features of a specific lesion. RESULTS: One hundred fifty-eight small early-enhancing lesions were detected in 75 (36%) of the 208 patients on the initial MR images. Of those 158 lesions, 104 were round or oval, 30 wedge shaped, 18 geographic (irregularly shaped), and six triangular. Among the 104 round or oval lesions, 54 (52%) disappeared or decreased in size on the latest MR images and were considered definite pseudolesions. Twenty-nine (28%) of the 104 round or oval lesions were classified as hepatocellular carcinoma (HCC) on the basis of their interval growth or pathologic confirmation. The remaining 21 (20%) lesions were stable in size and appearance and considered probable pseudolesions. For the other three shapes, 73% of wedge-shaped, 78% of geographic, and 67% of triangular lesions disappeared or decreased in size. CONCLUSION: Small early-enhancing hepatic lesions in patients with cirrhosis usually showed no interval growth or disappeared during serial contrast-enhanced dynamic MR imaging. Even though these lesions are round or oval, they may more frequently be pseudolesions than HCCs. (C) RSNA, 2002.