MRI与正电子发射体层摄影图像配准和融合技术在Alzhermer病诊断中的初步应用

目的　初步评价MR与正电子发射体层摄影（PET）图像配准和融合技术对Alzhermer病（AD）的诊断价值。方法　12例可能AD患者（53～83岁）和6例正常志愿者（45～71岁）行头颅MRI和PET扫描，两者间隔时间为1～32d，平均（18.2±11.6）d。分别用光盘和磁带机将MR和PET图像数据转移到图像工作站（SGIO2）上，再用统计学参数绘图（statisticalparametricmap，SPM）算法，自动行脑MR图像与PET图像的三维配准与融合。结果　PET所见完全符合AD改变者9例，可符合AD诊断、但需要与其他疾病相鉴别者3例。MRI根据特定脑结构测量作出AD诊断者11例，余1例未见异常改变。AD患者经配准处理的MRI可见内颞叶萎缩改变，PET显示大脑半球颞顶叶葡萄糖代谢减低区呈淡红色，融合图像可见大脑半球颞顶叶为红色代谢减低区。结论　配准图像可准确对比观察PET与MRI的异常改变，精确定位PET显示的病灶；融合图像增加了病灶的对比度。分析MRI与PET的配准与融合图像，全组12例患者均可作出AD的诊断。

The clinical preliminary use of co-registration and fusion of positron emission tomography and MR images in Alzheimer disease

Objective　To preliminarily evaluate the diagnostic value of co-registration and fusion of positron emission tomography and MR images in Alzheimer disease (AD). Methods　Twelve patients with AD (53-83 years) and six normal volunteer (45-71 years) were scanned by positron emission tomography (PET) and MR imaging. The interval between two examination was 1-32 days (average:18.2±11.6 days). The disc and magnetic tape were used to transfer the imaging data to image work station (SGI O2), then the special software for co-registration and fusion: Statistical Parametric Map was used to do automatic co-registration between PET and MR images of brain in 3D. Results　The findings of PET was completely accorded with the changes of AD in 9 patients (9/12), and accorded with AD, but should be differentiate from other diseases in 3 cases (3/12). According to the measurement of special cerebral structures, MR images could make the diagnosis of AD in 11 patients (11/12), and had no abnormal finding in 1 case. The medial temporal atrophy could be seen on the MR images co-registrated with PET in AD patients, on the other hand, PET demonstrated the pink color region of metabolic rate of glucose decreased in temporoparietal lobes of cerebral hemisphere. The similar findings depicted on fusion images as red color region of metabolic rate of glucose decreased in temporoparietal lobes. Conclusion　The co-registrated images can accurately observe the abnormal findings of PET and MR images, and fix the location of foci depicted by PET, in addition, fusion images increase the contrast of the foci. Analyzing the images of co-registration and fusion of PET and MRI can lead to the diagnosis of AD in all the patients.