Magnetic resonance iron-free nodules in genetic hemochromatosis

OBJECTIVE: In hemochromatosis, areas of normal hepatic magnetic resonance ( MR) signal intensity indicate the presence of iron-free-nodules, which are strongly suspected of being neoplastic. The goal of the study was to define the prevalence and the nature of these iron-free MR nodules at the time of diagnosis in 116 patients included in a prospective study assessing the ac curacy of MR imaging (MRI) in the quantification of liver iron overload. METHODS: Seventy-nine of the 116 patients had homozygous hemochromatosis on a phenotypic basis. Fifteen-millimeter-thick contiguous slices were perfor med using T1- and T2-weighted gradient echo sequences with a 0.5 Tesla magn et. RESULTS: Six of 79 homozygous hemochromatotic patients had one or more MR i ron-free nodules. Five of the six patients proved to have malignant tumors. Four of six iron-free nodules were hepatocellular carcinoma (5% in the hem ochromatosis group and 17.5% in hemochromatotic patients with severe fibros is). CONCLUSIONS: The present data confirm the high prevalence of liver cancer a t the time of diagnosis, mainly in cirrhotic patients greater than 45 years of age, and indicate that, when performing MRI for liver iron quantificati on, a complete hepatic MRI examination is preferable to a simple signal mea surement in patients at risk for hepatocellular carcinoma. (C) 1999 by Am. Cell. of Gastroenterology.