PET影像中自动提取脑功能区的研究

背景正电子发射断层成像(positronemissiontomography,PET)是一种能获取放射性示踪剂在活体中分布密度的定量图像断层显像技术.利用PET图像研究脑功能常用感兴趣区法,但随机误差大;而扫描探针显微镜(scanningprobe microscope,SPM)方法不适用于分析特定功能区.目的建立从PET影像中自动提取脑部功能区的方法.设计随机对照研究.地点和对象健康志愿者共28例,来自于上海第二医科大学附属瑞金医院,男、女各14例,年龄为12～81岁.将志愿者随机分为光线刺激组和视觉屏蔽组,各为14例.干预光刺激组在睁眼、静息状态下行PET检查,视觉屏蔽组在带眼罩、静息状态下行PET检查.主要观察指标将PET脑部图像非线性配准于Talairach图谱,根据各功能区的坐标,提取出功能区,分析Broadmann17区和邻近区域的放射性计数值.结果光刺激试验结果显示志愿者戴眼罩组与光刺激组的活动相比较,按α=0.05的检验水准进行进行两组间t检验,两组间Broad-mann17区放射性计数值差异有显著性意义(左脑P=0.0055;右脑P=0.018 1),其他功能区差异无显著性意义.结论基于图谱自动从PET图像中提取功能区的方法是有效的.

Automatic extractionof functional area of brain in positron emission tomography images

BACKGROUND: Positron emission tomography(PET) is a tomography imaging of quantitative images technique that enables distributed density of a radioactive tracer in vivo to be obtained. The region of interesting method (ROI) is commonly used to analyze brain function by PET image, but which may cause random errors. Scanning probe microscope(SPM) is not applicable to analyze the particular functional regions of the image data.OBJECTIVE: To establish a method that can automatically extract the brain functional area from PET image.DESIGN: A randomly controlled study.SETTING and PARTICIPANTS: A total of 28 healthy volunteers(14males, 14 females) aged from 12 to 81 years old, who came from the Affiliated Ruijin Hospital of the Second Medical University of Shanghai. The volunteers were randomly divided into light stimulation group and visual shield group with 14 in each.INTERVENTIONS: The hght stimulation group was examined with PET under the state of eyes opened and rest. The visual shield group was examined under the state of eyes patched and rest.MAIN OUTCOME MEASURES: PET brain image was registered to the Talairach Atlas nonlinearly. The functional areas were extracted in terms of the coordinates, and the radioactive counts of Broadmann 17 area and the other neighbor functional areas were analyzed.RESULTS: The Broadmann17 area had statistical significance in radioactive counts (Left cerebrum P＝ 0. 005 5; Right cerebrum P＝ 0. 018 1), and other functional areas had non-significant difference( P ＜ 0. 01), t-test between two groups(α =0. 05) was done.CONCLUSION: The method of automatic functional area extraction in PET images, which is based on the Talairch Atlas, is proved to be effective.