Effects of echo time on diffusion quantification of brain white matter at 1.5 T and 3.0 T.
The aim was to investigate the effects of echo time (TE) on diffusion quantification of brain white matter. Seven rhesus monkeys (all males; age, 4-6 years; weight, 5-7 kg) underwent diffusion tensor imaging (DTI) with a series of TEs in 1.5 T and 3.0 T MR scanners. The mean diffusivity (MD), fractional anisotropy (FA), primary (lambda(1)), and transverse eigenvalues (lambda(23)) were measured in a region of interest at the bilateral internal capsule. Pearson correlation showed that the FA and lambda(1) increased and lambda(23) decreased with TE both at 1.5 T and 3.0 T except for the MD. Repeated measurement analysis of variance (ANOVA) also showed significantly higher FA and lower MD and lambda(23) at 3.0 T than those at 1.5 T (P<0.01), but no statistical differences were found in lambda(1) between these two field strengths (P=0.709). These findings implied that TE and field strength might influence diffusion quantification in brain white matter.
Qin
Wen
W
Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Yu
Chun Shui
CS
Zhang
Fan
F
Du
Xiang Ying
XY
Jiang
Heng
H
Yan
Yu Xia
YX
Li
Kun Cheng
KC
D000465:Algorithms; D000818:Animals; D001921:Brain / Q000166:cytology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008253:Macaca mulatta; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity