T1 independent, T2* corrected MRI with accurate spectral modeling for quantification of fat: Validation in a fat-water-SPIO phantom

✍ Scribed by Catherine D.G. Hines; Huanzhou Yu; Ann Shimakawa; Charles A. McKenzie; Jean H. Brittain; Scott B. Reeder

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 581 KB
• Volume: 30
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.21957

✦ Synopsis

Abstract

Purpose:

To validate a T~1~‐independent, T~2~*‐corrected fat quantification technique that uses accurate spectral modeling of fat using a homogeneous fat‐water‐SPIO phantom over physiologically expected ranges of fat percentage and T~2~* decay in the presence of iron overload.

Materials and Methods:

A homogeneous gel phantom consisting of vials with known fat‐fractions and iron concentrations is described. Fat‐fraction imaging was performed using a multiecho chemical shift‐based fat‐water separation method (IDEAL), and various reconstructions were performed to determine the impact of T~2~* correction and accurate spectral modeling. Conventional two‐point Dixon (in‐phase/out‐of‐phase) imaging and MR spectroscopy were performed for comparison with known fat‐fractions.

Results:

The best agreement with known fat‐fractions over the full range of iron concentrations was found when T~2~* correction and accurate spectral modeling were used. Conventional two‐point Dixon imaging grossly underestimated fat‐fraction for all T~2~* values, but particularly at higher iron concentrations.

Conclusion:

This work demonstrates the necessity of T~2~* correction and accurate spectral modeling of fat to accurately quantify fat using MRI. J. Magn. Reson. Imaging 2009;30:1215–1222. © 2009 Wiley‐Liss, Inc.