Development of Correction for Signal-to-Noise Ratio Using a T2*With Improved Phase Method

作者：Ikemitsu Natsuki; Kanazawa Yuki^*; Matsumoto Yuki; Sasaki Toshiaki; Hayashi Hiroaki; Miyoshi Mitsuharu; Harada Masafumi

来源：Journal of Computer Assisted Tomography, 2018, 42(1): 117-123.

DOI：10.1097/RCT.0000000000000644

• magnetic resonance imaging
• susceptibility
• T-2(*) mapping
• echo time
• phase imaging

Objective This study aims to improve the signal-to-noise ratio (SNR) of the phase image focusing T-2(*) and to develop an improved phase (iPhase) image acquired high SNR.
Methods The iPhase images of phantom and brain were acquired with multi-echo spoiled gradient-echo. The phantom component was a gadopentetate dimeglumine (Gd-DTPA) solution made of different concentrations (0.1, 0.5, and 1 wt%) and Gd-DTPA (0.1, 0.5, and 1 wt%) with agar (1.0 wt%). We applied the iPhase image to susceptibility weighed image (SWI) and evaluated SNR of SWI.
Results In phantom study, SNRs of conventional SWI at each sample were 19.8, 15.7, 7.4, 20.0, 17.4, and 27.3, respectively. Signal-to-noise ratios of SWI derived from iPhase method were 29.5, 33.7, 21.7, 28.5, 24.3, and 14.7, respectively. Then, the SNR showed an improvement of 196% at maximum (for the Gd-DTPA 1 wt% sample). In healthy volunteer study, SWI derived from iPhase method had the good contrast between white matter and gray matter.
Conclusions The iPhase image was able to improve the phase SNR. Moreover, iPhase method makes it possible to obtain a high SNR image when applying to SWI.

• 出版日期2018-2