脊髓型多发性硬化脑灰质弥散张量成像研究

目的 运用DTI直方图分析,研究脊髓型多发性硬化（SMS）患者是否存在脑灰质异常及脑灰质DTI指标与临床评分的相关性.方法 对25例SMS患者和35例正常志愿者行常规MRI和DTI检查,分割提取脑灰质后,研究SMS患者脑灰质平均弥散率（MD）和分数各向异性（FA）直方图的异常变化.结果 OSMS患者脑灰质体积明显小于正常志愿者（P＜0.001）.OSMS患者脑灰质MD和FA直方图指标与正常志愿者间存在显著差异（P＜0.01）.在OSMS患者,所有脑灰质DTI直方图指标与扩展残疾状态评分（EDSS）均无相关性,但锥体束和感觉系统（PSS）评分与脑灰质平均MD（r=0.54,P=0.005）和MD直方图峰高（r=-0.41,P=0.04）中度相关.结论 OSMS患者脑灰质存在明显萎缩和弥散异常,这可能与继发于脊髓病变的逆行性脑灰质神经元变性有关.

Study on the brain gray matter in spinal form of multiple sclerosisusing diffusion tensor imaging

Objective To investigate whether patients with spinal form of multiple sclerosis (SMS) have brain gray matter (GM) damage by using diffusion tensor imaging (DTI) histogram analysis, and whether DTI-derived measures of the gray matter correlate with clinical scores. Methods Conventional and DTI scans were obtained from 25 patients with SMS and 35 control subjects. After segmentation of the brain GM, The abnormal changes of the mean diffusivity (MD) and fractional anisotropy (FA) histograms of the GM were studied. Results The average GM volume of patients with SMS was significantly lower than that of controls (P<0.001). All the MD and FA histogram-derived measures of the GM were significantly different between patients with SMS and controls (P<0.01). In patients with SMS, none of the considered measures correlated with Expanded Disability Status Scale (EDSS) scores. However, the pyramidal and sensory system (PSS) scores correlated with the average MD (r=0.54, P=0.005) and MD peak height (r =-0.41, P=0.04) of the NAGM. Conclusion The brain GM of patients with SMS had atrophy and occult damage, which probably caused by a retrograde degeneration of neurons secondary to spinal cord damage.