Simultaneous quantification of T2 and T′2 using a combined gradient echo-spin echo sequence at ultrahigh field

✍ Scribed by Eleanor F. Cox; Penny A. Gowland

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 322 KB
• Volume: 64
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.22522

✦ Synopsis

Abstract

Measuring T~2~ at 7.0 T is not trivial due to RF inhomogeneity effects, however, gradient echo sampling of a spin echo is insensitive to RF pulse errors, does not suffer from significant distortions, and allows T′~2~ and T~2~ to be estimated simultaneously. Gradient echo sampling of a spin echo results are relatively sensitive to noise and therefore fitting methods and timing parameters were optimized: a weighted linear fit reduced the errors in T~2~ compared to a nonlinear fit, the optimum spin echo time was approximately equal to the expected T~2~ and decreasing the number of gradient echoes minimized the error of the estimated T~2~. T~2~, T′~2~, and T*~2~ decreased with field strength in frontal gray matter, occipital gray matter, and white matter, with T~2~ having a linear dependence (frontal gray matter: 87, 76, 47 ms, occipital gray matter: 80, 68, 46 ms and white matter: 80, 71, 47 ms at 1.5, 3.0 and 7.0 T, respectively). Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.