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Whole‐brain chemical exchange saturation transfer imaging with optimized turbo spin echo readout
Author(s) -
Zhang Yi,
Yong Xingwang,
Liu Ruibin,
Tang Jibin,
Jiang Hongjie,
Fu Caixia,
Wei Ruili,
Hsu YiCheng,
Sun Yi,
Luo Benyan,
Wu Dan
Publication year - 2020
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.28184
Subject(s) - fast spin echo , flip angle , nuclear magnetic resonance , imaging phantom , spin echo , magnetic resonance imaging , magnetization transfer , gradient echo , artifact (error) , scanner , pulse sequence , sequence (biology) , physics , materials science , chemistry , optics , computer science , medicine , radiology , artificial intelligence , biochemistry
Purpose To achieve fast whole‐brain chemical exchange saturation transfer (CEST) imaging with negligible susceptibility artifact. Methods An optimized turbo spin echo readout module, also known as sampling perfection with application optimized contrasts by using different flip angle evolutions (SPACE), was deployed in the CEST sequence. The SPACE‐CEST sequence was tested in a phantom, 6 healthy volunteers, and 3 brain tumor patients on a 3T human scanner. A dual‐echo gradient echo sequence was used for B 0 inhomogeneity mapping. In addition, the proposed SPACE‐CEST sequence was compared with the widely used turbo spin echo‐CEST sequence for amide proton transfer–weighted (APTw) images. Results The SPACE‐CEST sequence generated highly consistent APTw maps to those of the turbo spin echo‐CEST sequence in the phantom. In healthy volunteers, the SPACE‐CEST sequence yielded whole‐brain 2.8‐mm isotropic APTw source images within 5 minutes, with no discernible susceptibility artifact. As for the B 0 maps in the whole brain, its mean, median, and standard deviation B 0 offset values were 5.0 Hz, 5.6 Hz, and 16 Hz, respectively. Regarding the APTw map throughout the whole brain, its mean, median, and standard deviation values were 0.78%, 0.56%, and 1.74%, respectively. The SPACE‐CEST sequence was also successfully applied to a postsurgery brain tumor patient, suggesting no disease progression. In addition, on the newly diagnosed brain tumor patients, the SPACE‐CEST and turbo spin echo‐CEST sequences yielded essentially identical APTw values. Conclusion The proposed SPACE‐CEST technique can rapidly generate whole‐brain CEST source images with negligible susceptibility artifact.