强迫症患者SPECT测定局部脑血流分布中参考区的选择

目的比较选择全脑和小脑两种参考区作为归一化参数在SPM分析强迫症患者的局部脑血流(rCBF)变化.方法受检者为13例OCD病人(OCD组)和23例年龄相匹配的健康志愿者(CN组).99mTc-ECDSPECT脑血流检查后,利用MRIcro和SPM工具软件,分别以全脑和小脑作为参考区,按成组设计分析OCD组和CN组两组间的rCBF分布差异(rCBF增高区和降低区).结果用小脑作为参考区,SPM分析显示OCD组有7个脑区rCBF发生变化;而用全脑作为参考区,SPM显示除有以上7个区域的血流变化外,还包括小脑的1个区域在内的17个区域的rCBF变化.结论强迫症患者小脑的脑血流发生变化,以此作为参考区不但会忽略小脑本身血流变化,还可掩盖与小脑血流变化相关的脑区.

A Comparative Study of Selection of Different Reference Areas in SPECT Image of OCD Compulsive Disorder Using SPM Analyses

Objective To study the distribution variations of regional cerebral blood flow (rCBF) in obsessive compulsive disorder (OCD) patients by alternation of designating the cerebellum and the global brain as normalizing reference. Methods The rCBF measurements using 99m Tc-ethyl cysteinate dimer (ECD) SPECT were performed on 13 OCD patients and 23 age-matched healthy volunteers. The rCBF distribution (including increased and decreased) was compared between these group samples using SPM and MRIcro software after normalization by designating the cerebellum and the glo bal brain as reference separately. ResultsThere were seven clusters in the OCD patients brain showing difference in the rCBF from the volunteers when the cerebellum was designated as normalizing reference. While the global brain was chosen as reference, OCD showed 24 clusters of regional distribution variations, including all the clusters found using the solution one normalization. Further more, SPM showed the rCBF of the cerebellum itself was different from the normal group. Conclusion For distribution variations of the rCBF in the cerebellum, designating the cerebrum as normalizing reference will not only overlook the change of the rCBF itself but also mask those brain regions in relation with the cerebellum.