Magnetic resonance imaging in the diagnosis of tumors of the liver.

To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of liver tumors, MR imaging was performed in 70 patients, 30 with normal or cirrhotic liver, 15 with benign tumors and 25 with malignant tumors. MR imaging was carried out with a 0.5-Tesla superconducting magnet and was made using a spin-echo technique, from which T1 and T2-weighted images were obtained, and also T1 and T2 values were measured. Hemangiomas and cysts were demonstrated as sharply circumscribed homogeneous masses of low- or high-intensity on each image. Hepatomas were revealed as low-, iso- and high-intensity masses on both images. The minimum size of hepatoma detected, 1 cm in diameter, exhibited uniform intensity. Large hepatomas showed a mosaic pattern of different intensities, a low-intensity area around the mass, and a capsular pattern. The majority of metastatic tumors demonstrated a characteristic irregularity at the periphery of the mass. There were significant differences in T1 and T2 values between benign and malignant tumors. These results suggest that MR imaging is useful not only in the detection but also in the differentiation of liver tumors and can permit evaluation of the architecture of the tumor.