RT Journal Article
SR Electronic
T1 T2* Mapping with Background Gradient Correction Using Different Excitation Pulse Shapes
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
DO 10.3174/ajnr.A3021
A1 N.M. Hirsch
A1 C. Preibisch
YR 2012
UL http://www.ajnr.org/content/early/2012/07/26/ajnr.A3021.abstract
AB SUMMARY: Background gradients induced by magnetic susceptibility variations near air-filled cavities in the brain cause signal-intensity loss in gradient-echo images and shorten T2* considerably. With a correction method in which the exponential decay is restored with section-profile-dependent correction factors, parts of the signal intensity can be recovered. While uncorrected T2* values drop by 20% at a gradient strength of 75 μT/m, with correction and exponential excitation pulses, this boundary is pushed to 220 μT/m.