PURPOSE: To assess the role of magnetic resonance (MR) imaging in dete
ction and quantification of liver iron overload. MATERIALS AND METHODS
: MR imaging at 0.5 T was prospectively performed on 77 patients (67 w
ith liver iron overload and 10 without) who underwent a liver biopsy w
ith biochemical determination of the liver iron concentration (LIC) (n
ormal, <36 mu mol per gram of liver tissue [dry weight]). Ratios of si
gnal intensities and liver T2 relaxation time were calculated from ima
ges obtained with spin-echo and breath-hold gradient-echo (GRE) sequen
ces. RESULTS: Liver-to-tissue signal intensity ratios were better corr
elated with LIC than T2 relaxation time. Long-echo-time GRE sequences
were the most sensitive for detection of slight overload. Thus, high s
ensitivity (94%) and specificity (90%) were obtained with a liver-to-f
at ratio threshold of 1. The quantification of iron with MR imaging wa
s accurate when the LIC was 80-300 mu mol/g. For heavy overload, above
300 mu mol/g, quantification was impossible owing to complete signal
loss. Pancreatic and splenic signal intensity were unchanged in most c
ases. CONCLUSION: This method, which can be improved by using more sen
sitive sequences with a high-field-strength system, should be competit
ive with biopsy for the diagnosis of substantial liver iron overload.