Effects of repetition time and field strength on diffusion indices of brain white matter

VernacularTitle:重复时间和场强对脑白质弥散张量成像定量研究的影响
Author: Wen QIN ; Kuncheng LI ; Chunshui YU ; Fan ZHANG
Publication Type:Journal Article
Keywords: Diffusion tensor imaging; Repetition time; Field strength; Signal to noise ratio
From: Chinese Journal of Medical Imaging Technology 2009;25(7):1127-1130
CountryChina
Language:Chinese
Abstract: Objective To observe whether repetition time (TR) and field strengths have effects on diffusion indices of brain white matter. Methods Seven rhesuses underwent diffusion tensor MR imaging (DT-MRI) with a series of TRs (from 500 to 6000 ms) at 1.5T and 3.0T MR scanners, respectively. The mean diffusivity (MD), fractional anisotropy (FA), primary (λ1) and transverse eigenvalues (λ2, 3) were measured in region of interest (ROI) at the posterior limb of internal capsule. Pearson correlation analysis and two-way ANOVA were performed. Results None of the diffusion indices was correlated with TR (P＞0.05) when SNR was high enough (SNR>35). FA was significantly higher and the MD and λ2, 3 were significantly lower at 3.0T than those at 1.5T (P＜0.001). No significant difference of λ1 was found between the two field strengths (P＞0.05). Conclusion Field strength may influence diffusion quantification, but not for TR, which should be considered in multi-center studies.