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Imaging of shifted stimulated echoes and multiple spin echoes

✍ Scribed by Susumu Mori; Ralph E. Hurd; Peter C. M. Van Zijl

Publisher
John Wiley and Sons
Year
1997
Tongue
English
Weight
568 KB
Volume
37
Category
Article
ISSN
0740-3194

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✦ Synopsis

Abstract

It is shown that a repetitive pulse sequence consisting of two 90Β° pulses and gradients in a 1:2 ratio around the second 90Β° pulse generates interscan shifted stimulated echoes (SSTEs) and intrascan multiple spin echoes (MSEs). Separation of these two types of signals is accomplished using specific gradient crusher schemes. The intensity of the SSTEs is an order of magnitude larger than that of the MSEs and determines the signal contrast if both effects are selected simultaneously. The SSTE sequence generates improved contrast between gray and white matter, even at high field, which is explained in terms of increased inverse T~1~‐weighting for the interscan echo. The MSE image has low signal to noise and no detectable contrast. The effect of interscan diffusion weighting is also discussed.

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