T1D‐weighted ihMT imaging – Part I. Isolation of long‐ and short‐T1D components by T1D‐filtering. Issue 5 (17th January 2022)

• Record Type: Journal Article
• Authors: Hertanu, Andreea; Soustelle, Lucas; Le Troter, Arnaud; Buron, Julie; Le Priellec, Julie; Carvalho, Victor N. D.; Cayre, Myriam; Durbec, Pascale; Varma, Gopal; Alsop, David C.; Girard, Olivier M.; Duhamel, Guillaume
• Is Part Of: Magnetic resonance in medicine. Volume 87:Issue 5(2022)
• Page Start: 2313
• Page End: 2328
• Publication Date: 2022-01-17
• Subjects: band‐pass T1D‐filter -- bi‐T1D model -- high‐pass T1D‐filter -- ihMT T1D‐filtering -- low duty‐cycle; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.29139
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract: Purpose: To identify T1D ‐filtering methods, which can specifically isolate various ranges of T1D components as they may be sensitive to different microstructural properties. Methods: Modified Bloch‐Provotorov equations describing a bi‐T1D component biophysical model were used to simulate the inhomogeneous magnetization transfer (ihMT) signal from ihMTRAGE sequences at high RF power and low duty‐cycle with different switching time values for the dual saturation experiment: Δ t = 0.0, 0.8, 1.6, and 3.2 ms. Simulations were compared with experimental signals on the brain gray and white matter tissues of healthy mice at 7T. Results: The lengthening of Δ t created ihMT high‐pass T1D ‐filters, which efficiently eliminated the signal from T1D components shorter than 1 ms, while partially attenuating that of longer components (≥ 1 ms). Subtraction of ihMTR images obtained with Δ t = 0.0 ms and Δ t = 0.8 ms generated a new ihMT band‐pass T1D ‐filter isolating short‐T1D components in the 100‐µs to 1‐ms range. Simulated ihMTR values in central nervous system tissues were confirmed experimentally. Conclusion: Long‐ and short‐T1D components were successfully isolated with high RF power and low duty‐cycle ihMT filters in the healthy mouse brain. Future studies should investigate the various T1D ‐range microstructural correlations in in vivo tissues.