R2* imaging of transfusional iron burden at 3T and comparison with 1.5T

✍ Scribed by Pippa Storey; Alexis A. Thompson; Christine L. Carqueville; John C. Wood; R. Andrew de Freitas; Cynthia K. Rigsby

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 929 KB
• Volume: 25
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.20816

✦ Synopsis

Abstract

Purpose

To determine normative R2* values in the liver and heart at 3T, and establish the relationship between R2* at 3T and 1.5T over a range of tissue iron concentrations.

Materials and Methods

A total of 20 healthy control subjects and 14 transfusion‐dependent patients were scanned at 1.5T and 3T. At each field strength R2* imaging was performed in the liver and heart.

Results

Normative R2* values in the liver were estimated from the control group to be 39.2 ± 9.0 second^−1^ at 1.5T and 69.1 ± 21.9 second^−1^ at 3T. Normative cardiac values were estimated as 23.4 ± 2.2 second^−1^ at 1.5T and 30.0 ± 3.7 second^−1^ at 3T. The combined R2* data from patients and control subjects exhibited a linear relationship between 3T and 1.5T. In the liver, the line of best fit to the 3T vs. 1.5T data had a slope of 2.00 ± 0.06 and an intercept of −11 ± 4 second^−1^. In the heart, it had a slope of 1.88 ± 0.14 and an intercept of −15 ± 4 second^−1^.

Conclusion

These preliminary data suggest that the iron‐dependent component of R2* scales linearly with field strength over a wide range of tissue iron concentrations. The incidence of susceptibility artifacts may, however, also increase with field strength. J. Magn. Reson. Imaging 2007;25:540–547. © 2007 Wiley‐Liss, Inc.