Magnetic resonance imaging simulation with spin-lock preparations to detect tiny oscillatory magnetic fields

• Published in: Journal of magnetic resonance (1997) 2021-03, Vol.324, p.106910-106910, Article 106910
• Main Authors: Ueda, Hiroyuki, Ito, Yosuke, Oida, Takenori, Taniguchi, Yo, Kobayashi, Tetsuo
• Format: Article
• Language: English
• Subjects: Bloch equation; GPU-driven MR imaging simulation; Spin-locked Mz; Stimulus-induced rotary saturation
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2020.106910

[Display omitted] •MR imaging simulation with spin-lock preparations.•Comparison of the simulated images with experimental ones.•Analytical solution of the Bloch equation during RF pulse and gradient field.•The simulated images with the sufficient sub-voxels agreed with the experimental ones.•GPU parallel computing is effective to avoid the impractical calculation time. Spin-lock preparation was studied to detect tiny oscillatory magnetic fields such as a neural magnetic field without the blood oxygen level-dependent effect. This approach is a direct measurement and independent of static magnetic field strength. Accordingly, it is anticipated as a feasible functional magnetic resonance imaging (fMRI) in low and ultra-low-field MRI. Several reports have been published on spin-lock preparation but reports on imaging simulation are rare. Research in this area can assist in investigating magnetic resonance signal changes and, accordingly, can help to develop new spin-lock methods. In this study, we propose an imaging simulation method with an analytical solution using the Bloch equation. To demonstrate the feasibility of our proposed method, we compared simulated images with experimental results in which the number of sub-voxels and the amplitude and phase of the target oscillatory magnetic fields varied. In addition, we also applied graphics processing unit parallel computing and investigated the feasibility of avoiding an impracticable calculation time by doing so.