关键词:  磁共振, 扩散张量成像, 腰椎间盘, 定量分析

Abstract:

Objective　To study the microstructure properties and quality analysis of human lumbar intervertebral disc by MR-DTI.　Methods　20 healthy adults(20~57 years, averagely 37.4 years) were investigated under 1.5T Magnetic field. Imaging protocol included RF coil: CTL spine coil, Pulse sequence: Single-shot spin-echo echo planner imaging (SE-EPI), b-value: 600mm-2s, No. of gradient direction: 15, TE: 61 ms, TR: 3500 ms, No cardiac gating/VCG triggering, FOV: 48mm×139mm×80 mm, NEX: 3, Saturation pulse outside the region of interest (ROI), Shimming along the VOI.　Results　Higher FA in AF than NP suggested that diffusion in AF was more anisotropic than that in NP(P<0.05). The trace value in NP was higher than that in AF. This may suggested that the diffusion was more readily to take place in NP than in AF (Higher magnitude of diffusion in NP). In both AF and NP, the axial diffusivity was higher than the radial one, suggesting that diffusion in both medium was usually dominated in one direction, i.e. the axial direction.　Conclusions　The result gives an overview to the structure of IVD (AF and NP) based on their diffusion properties. The diffusion in AF is more anisotropic than that in NP. The diffusion is more readily to take place in NP than in AF. The diffusion in both medium is usually dominated in one direction, i.e. the axial direction. It is expected that in case of IVD disease, there will be structural damage to AF (AF tearing) and this will alter the local diffusion property.

Key words: Magnetic imaging, Diffusion tensor imaging, Lumbar intervertebral disc, Quantitative analysis