Reproducing Gradient Field Application to Localize Magnetic Resonance Signals Using MRI Simulation
- Author:
Noriyuki TAWARA
1
;
Hiroyuki SUGIMORI
;
Kojiro YAMAGUCHI
Author Information
- Publication Type:Technical Note
- From:Investigative Magnetic Resonance Imaging 2025;29(4):225-232
- CountryRepublic of Korea
- Language:English
- Abstract: This study aimed to reproduce, through MRI simulation, the process by which gradient fields are applied during signal acquisition to obtain spatial information in MR signals. A digital phantom containing three cylinders filled with the simulated material was used to acquire MR signals by gradient echo using MRI simulations, performed using a pulsesequence diagram. MR signals were acquired under three different conditions: a) without a gradient field applied, b) with only a gradient field applied, and c) with a dephasing lobe and gradient field applied. The MR signal acquired under (a) was time-domain data that, after Fourier transformation (FT), yielded a single spectral data corresponding to the resonance frequency. However, when gradient field is applied to obtain spatial information, phase dispersion (dephasing) inevitably occurs over time; furthermore, this dephasing is superimposed. Consequently, the MR signals acquired in b) and c) were confirmed to be frequency-domain data after FT, as they were obtained under gradient field application. Furthermore, the necessity of the dephasing lobe was confirmed, as data reflecting the nature of the k-space could not be obtained without its inclusion during gradient field application during signal acquisition.
