Ansar M Ashik B, Osaki Yasuhiro, Kazui Hiroaki, Oku Naohiko, Takasawa Masashi, Kimura Yasuyuki, Begum Nurun N, Ikejiri Yoshitaka, Takeda Masatoshi, Hatazawa Jun
Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Japan.
Ann Nucl Med. 2006 Oct;20(8):511-7. doi: 10.1007/BF03026814.
Statistical parametric mapping (SPM) was employed to investigate the regional decline in cerebral blood flow (rCBF) as measured by 99mTc-hexamethyl propylene amine oxime (HMPAO) single photon emission computed tomography (SPECT) in mild Alzheimer's disease (AD). However, the role of the post reconstruction image processing on the interpretation of SPM, which detects rCBF pattern, has not been precisely studied. We performed 99mTc-HMPAO SPECT in mild AD patients and analyzed the effect of linearization correction for washout of the tracer on the detectability of abnormal perfusion.
Eleven mild AD (NINCDS-ADRDA, male/female, 5/6; mean+/-SD age, 70.6+/-6.2 years; mean+/-SD mini-mental state examination score, 23.9+/-3.41; clinical dementia rating score, 1) and eleven normal control subjects (male/female, 4/7; mean+/-SD age, 66.8+/-8.4 years) were enrolled in this study. 99mTc-HMPAO SPECT was performed with a four-head rotating gamma camera. We employed linearization uncorrected (LU) and linearization corrected (LC) images for the patients and controls. The pattern of hypoperfusion in mild AD on LU and LC images was detected by SPM99 applying the same image standardization and analytical parameters. A statistical inter image-group analysis (LU vs. LC) was also performed.
Clear differences were observed between the interpretation of SPM with LU and LC images. Significant hypoperfusion in mild AD was found on the LU images in the left posterior cingulate gyrus, right precuneus, left hippocampus, left uncus, and left superior temporal gyrus (cluster level, corrected p < 0.005). With the LC images, significant hypoperfusion in AD was found only in the bilateral posterior cingulate gyrus and left precuneus (cluster level, corrected p < 0.005). A pattern of greater rCBF distribution at the high flow cortices and low flow cortices was observed on LC and LU images, respectively, in the case of both controls and mild AD patients.
Hippocampal hypoperfusion could be detected by means of SPM in the LU images but not in the LC images. The results of SPM may vary in 99mTc-HMPAO SPECT with or without linearization correction, which should be carefully evaluated when interpreting the pattern of rCBF changes in mild Alzheimer's disease.
采用统计参数映射（SPM）技术，通过99mTc-六甲基丙烯胺肟（HMPAO）单光子发射计算机断层扫描（SPECT）研究轻度阿尔茨海默病（AD）患者脑血流（rCBF）的区域下降情况。然而，重建后图像处理在检测rCBF模式的SPM解释中的作用尚未得到精确研究。我们对轻度AD患者进行了99mTc-HMPAO SPECT检查，并分析了示踪剂洗脱的线性化校正对异常灌注检测能力的影响。
本研究纳入了11例轻度AD患者（NINCDS-ADRDA标准，男/女，5/6；平均±标准差年龄，70.6±6.2岁；平均±标准差简易精神状态检查表评分，23.9±3.41；临床痴呆评定量表评分，1）和11名正常对照者（男/女，4/7；平均±标准差年龄，66.8±8.4岁）。使用四头旋转γ相机进行99mTc-HMPAO SPECT检查。我们对患者和对照者采用了未校正线性化（LU）和校正线性化（LC）图像。通过应用相同图像标准化和分析参数的SPM99检测LU和LC图像上轻度AD患者的灌注不足模式。还进行了图像组间统计学分析（LU与LC）。
在使用LU和LC图像进行SPM解释时观察到明显差异。在LU图像上，轻度AD患者的左侧后扣带回、右侧楔前叶、左侧海马、左侧钩回和左侧颞上回存在明显灌注不足（聚类水平，校正p<0.005）。对于LC图像，AD患者仅在双侧后扣带回和左侧楔前叶存在明显灌注不足（聚类水平，校正p<0.005）。在对照者和轻度AD患者中，分别在LC和LU图像上观察到高血流皮质和低血流皮质处rCBF分布模式的差异。
通过SPM可以在LU图像而非LC图像上检测到海马灌注不足。在99mTc-HMPAO SPECT中，有无线性化校正时SPM结果可能不同，在解释轻度阿尔茨海默病rCBF变化模式时应仔细评估。
