Abstract
A new method for imaging magnetization transfer (MT) asymmetry with no separate saturation pulse is proposed in this article. MT effects were generated from sequential two-dimensional balanced steady-state free precession imaging, where interslice MT asymmetry was separated from interslice blood flow and magnetic field inhomogeneity with alternate ascending/descending directional navigation (ALADDIN). Alternate ascending/descending directional navigation provided high-resolution multislice MT asymmetry images within a reasonable imaging time of ∼3 min. MT asymmetry signals measured with alternate ascending/descending directional navigation were 1-2% of baseline signals (N = 6), in agreement with those from the conventional methods. About 70% of MT asymmetry signals were determined by the first prior slice. The frequency offset ranges in this study were >8 ppm from the water resonance frequency, implying that the MT effects were mostly associated with solid-like macromolecules. Potential methods to make alternate ascending/descending directional navigation feasible for imaging amide proton transfer (∼3.5 ppm offset from the water resonance frequency) were discussed.
Original language | English (US) |
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Pages (from-to) | 1702-1710 |
Number of pages | 9 |
Journal | Magnetic Resonance in Medicine |
Volume | 65 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2011 |
Externally published | Yes |
Keywords
- alternate ascending/descending directional navigation
- amide proton transfer
- balanced steady-state free precession
- chemical exchange saturation transfer
- magnetization transfer
- magnetization transfer asymmetry
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging