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Cooperative T 1 and T 2 effects on contrast using a new driven inversion spin‐echo (DISE) MRI pulse sequence
Author(s) -
Conturo Thomas E.,
Kessler Robert M.,
Beth Albert H.
Publication year - 1990
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910150307
Subject(s) - pulse sequence , spin echo , nuclear magnetic resonance , contrast (vision) , physics , fast spin echo , sequence (biology) , magnetic resonance imaging , chemistry , optics , medicine , radiology , biochemistry
A pulse sequence is presented for obtaining a single image with combined T 1 /T 2 weighting. T 2 relaxation is made to increase intensity, in cooperation with the effect of T 1 relaxation, by providing T 2 weighting with a 90°‐180°‐90° driven inversion pulse triplet in an inversion recovery method. Unlike the inversion spin‐echo method having a short inversion time (TI), signals in the new driven inversion spin‐echo (DISE) method need not be negative and the most T 1 ‐sensitive region of the recovery curve can be used. Selecting sensitivity to one relaxation time does not degrade the sensitivity to the other relaxation time. T 1 sensitivity is thus extended to longer echo times (TE intervals), T 2 sensitivity is extended to longer TI intervals, and the combined T l / T 2 ‐weighted technique with intermediate TE and T 1 has highly cooperative and near‐maximal T 1 and T 2 effects on contrast. Intensity is not multiplicatively degraded by T 1 and T 2 weighting so that the signal‐to‐noise of the combined T 1 / T 2 ‐weighted method is high. High intensity and T I and T 2 cooperatively occur for a much wider range of relaxation times, and especially for images heavily weighted to the pathologic intermediate and long T 1 and T 2 Rgime. © 1990 Academic Press, Inc.