Hepatic iron overload in thalassemic patients: proposal and validation of an MRI method of assessment.

Abstract

A simple, accurate, reproducible and noninvasive method of body iron overload assessment would be of great clinical use. Objective. The purpose of the study was the implementation of a 0. 5-T MRI method for liver iron overload measurement. Thirty patients with thalassemia major took part in the study. Liver and paraspinal muscle signal intensity (SI) measurements were performed on T1-weighted images and normalized on a standard phantom, and a subjective hemochromatosis grading scale was made on both T1- and T2-weighted images. Serum ferritin levels and tissue iron from liver biopsy specimens were determined for comparison. A close correlation was found between bioptic liver iron and both the liver-to-phantom SI ratio (r = -0.88) and the subjective grading scale (rho = 0.89). Serum ferritin correlated poorly with liver iron deposition, whether assessed by biopsy (r = 0. 62) or MRI (r = -0.69). Both the subjective and the quantitative MRI methods proposed here are clinically valuable, with the former being adequate for a gross, the latter for an accurate estimation of tissue iron overload.