Simultaneous measurement of iron concentration and fat infiltration in the liver with a single-breathhold 16-echo gradient echo sequence

Abstract

Introduction In the past few years there have been several methods to determine fat infiltration of the liver, some of them being expensive commercial applications for MRI or expensive services provided by some companies to which the MRI data are sent for evaluation. β -Thalassemia patients with liver iron overload and fat infiltration require determination of both. Purpose To develop and certify a method for simultaneous determination of iron overload and fat infiltration of the liver with a 16-echo single breath-hold gradient echo sequence and compare the calculated results of fat infiltration with those determined by Proton MR spectroscopy (MRS) of the liver. Materials and methods 500 patients were examined at 1.5 Tesla (Signa HDxt, GE, Milwaukee, USA) with a 16-echo sequence at two different echo time ranges (a short and a long one for moderate and low iron overload, respectively). A least-squares-fit of the acquired data yielded T2* values and fat fraction. MR spectra from the liver were acquired from 40 patients. Results The agreement for liver fat infiltration determined by the proposed MRI technique and the MRS method was excellent. The gradient echo method is sensitive enough for fat fractions as low as 1%. Fat infiltration results are accurate for iron concentrations as high as 10 mg/g dry tissue. Conclusion The gradient-echo method is quick and accurate and is a reliable alternative to other expensive methods. Furthermore it provides iron overload and fat infiltration determination simultaneously, in a single breath-hold. Disclosure None of the authors has anything to declare.