扩散张量成像及磁化传递成像评价正常婴幼儿脑白质髓鞘化研究

The Study of Normal Infants Myelination by Diffusion Tensor Imaging and Magnetization Transfer Imaging

目的探讨MR扩散张量成像(DTI)和磁化传递成像(MTI)两种方法评价正常婴幼儿脑白质髓鞘化过程的意义。资料与方法对30名正常婴幼儿行常规MRI及DTI、MTI检查。运用感兴趣区(ROI)技术测定脑内13个脑白质ROI的表观扩散系数(ADCiso)、各向异性指数(FA)、磁化传递率(MTR)值。用13个ROIMTR值、ADCi-so、FA的平均值分别代表相应的全脑值。结果脑白质区局部及全脑ADCiso值与年龄呈负相关。除双侧小脑脚外,各个脑白质ROI局部FA值及全脑FA值与年龄无相关性。局部及全脑MTR值与年龄呈正相关。结论DTI及MTI在正常婴幼儿脑白质髓鞘化过程中有一定的变化规律,可提示髓鞘化病理生理过程。

Objective To evaluate the significance of diffusion tensor imaging and magnetization transfer imaging in assessing normal infants white matter myelination. Materials and Methods 30 cases of normal infants were performed by conventional MR imaging, diffusion tensor imaging and magnetization transfer imaging. Apparent diffusion coefficients （ADCiso）, fractional anisotropy（FA） , and magnetization transfer ratios （MTRs） were measured in the 13 WM ROIs. A whole brain MTR, ADCiso, FA was computed by using the means of all ROIs. Results The correlation of ADCiso with age was negative. No difference of correlation of FA with ages except the cerebellum, the correlation of MTR with age was positive. Conclusion DTI and MTI have a potential role for detecting myelination in the normal infants.