Department of Radiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-0022, Japan.
Department of Radiology, Omori Medical Center, Toho University, 6-11-1 Omorinishi, Ota-ku, Tokyo, 143-0015, Japan.
Ann Nucl Med. 2020 Jul;34(7):502-511. doi: 10.1007/s12149-020-01477-4. Epub 2020 May 24.
We examined the diagnostic value of brain perfusion single-photon emission computed tomography (SPECT) using voxel-based statistical analysis with CT-based attenuation correction (CT-AC) by comparing it to that with Chang's AC in mild cognitive impairment (MCI) patients and attempted to locate brain areas that are good indicators predicting the progression of MCI.
Twenty-six individuals matched for age, educational background and initial Mini-Mental State Examination (MMSE) score of more than 24 underwent SPECT with N-isopropyl-4-[I]iodoamphetamine and were assigned to 2 groups: the stable MCI (S-MCI) group comprising 11 subjects who maintained their MMSE score (mean 27.0) during at least a 1-year follow-up period (mean 37.2 months) and the progressive MCI (P-MCI) group comprising 15 subjects whose MMSE scores decreased by 3 or more points (from 26.4 to 21.4, mean). The diagnostic values of the two AC methods for discriminating P-MCI from S-MCI were compared using voxel-based statistical analysis in the lobe (Level 2) and lobule/gyrus levels (Level 3).
Receiver operating characteristic analysis revealed that the area under the curve (AUC) was higher with CT-AC than with Chang's AC in the left temporal and limbic lobes in Level 2. In Level 3, the AUC in the left middle temporal gyrus was higher with CT-AC (0.852) than with Chang's AC (0.827). There were differences between the gyri/lobules that showed higher AUCs with CT-AC and those that showed higher AUCs with Chang's AC. When the gyri with the 4 highest AUCs were combined, AUC (0.897) and accuracy (84.6%) were better with CT-AC than with Chang's AC (0.806 and 80.8%). Surprisingly, the AUCs in the posterior cingulate gyrus and precuneus, excluding the AUC in the right precuneus with Chang's AC (0.715), were no more than 0.70 and less useful.
CT-AC may allow brain perfusion SPECT to reflect more exact neuropathic changes in MCI that would cause progression of early AD. CT-AC in conjunction with voxel-based statistical analysis could possess higher diagnostic accuracy for exacerbation of disease implying early Alzheimer changes in MCI patients, with decreases in cerebral perfusion in the left temporal and limbic lobes representing good indicators.
我们通过比较脑灌注单光子发射计算机断层扫描（SPECT）基于体素的统计分析与 Chang 衰减校正（CT-AC）的诊断价值，试图定位能够预测轻度认知障碍（MCI）进展的脑区，从而评估基于 CT-AC 的 SPECT 在 MCI 患者中的诊断价值。
26 名年龄、教育背景和初始简易精神状态检查（MMSE）评分均大于 24 的个体接受了 N-异丙基-4-[I]碘安非他命 SPECT，并分为 2 组：稳定 MCI（S-MCI）组包括 11 名在至少 1 年的随访期（平均 37.2 个月）中 MMSE 评分保持不变（平均 27.0）的患者；进展性 MCI（P-MCI）组包括 15 名 MMSE 评分下降 3 分或更多（从 26.4 到 21.4，平均）的患者。采用基于体素的统计分析方法在叶（2 级）和小叶/脑回水平（3 级）比较两种 AC 方法对 P-MCI 与 S-MCI 进行鉴别诊断的诊断价值。
受试者工作特征分析显示，在 2 级的左颞叶和边缘叶中，CT-AC 的曲线下面积（AUC）高于 Chang's AC；在 3 级中，左中颞叶的 AUC 高于 Chang's AC（0.852）。CT-AC 组与 Chang's AC 组相比，具有更高 AUC 的脑回/脑叶存在差异。当将具有 4 个最高 AUC 的脑回/脑叶组合在一起时，CT-AC 的 AUC（0.897）和准确性（84.6%）优于 Chang's AC（0.806 和 80.8%）。令人惊讶的是，后扣带回和楔前叶的 AUC 均不超过 0.70，其诊断价值较低，排除了 Chang's AC 右侧楔前叶的 AUC（0.715）。
CT-AC 可能使脑灌注 SPECT 更准确地反映导致早期 AD 进展的 MCI 神经病变变化。CT-AC 结合基于体素的统计分析可能对 MCI 患者疾病恶化具有更高的诊断准确性，提示早期阿尔茨海默氏变化，左颞叶和边缘叶的脑灌注减少是很好的指标。
