The diagnostic value of SPECT with Tc 99m HMPAO in Alzheimer's disease
The diagnostic value of SPECT with Tc 99m HMPAO in Alzheimer's disease
复制标题
Tc 99m HMPAO SPECT 对阿尔茨海默病的诊断价值
作者：
J. Claus;F. Harskamp;M. Breteler;E. Krenning;I. Koning;T. Cammen;A. Hofman;D. Hasan
我们根据 NINCDS-ADRDA 标准，研究了使用锝 99m 标记的六甲基丙烯胺肟 (Tc 99m HMPAO) 进行单光子发射计算机断层扫描 (SPECT) 对 48 名疑似阿尔茨海默病 (AD) 患者和从一项基于人群的研究中招募的 60 名对照者的诊断准确性。通过逻辑回归，我们确定颞叶区域脑血流量减少是患者和对照组之间的最佳区分变量。接受者-操作者特征曲线显示，SPECT 的辨别能力随着痴呆严重程度的增加而提高。当特异性设置为 90% 时，轻度 AD 的敏感性为 42%，中度 AD 为 56%，重度 AD 为 79%。对于轻度 AD 患者，计算了诊断增益作为疾病存在先验概率的函数。当先验概率变化在 50% 左右时，对于轻度 AD 患者，阳性测试结果的诊断增益很大（最多 34%），但阴性测试结果的诊断增益较差。结果表明，SPECT 作为疑似轻度 AD 患者的诊断辅助手段的实际用途仅限于临床上存在相当大的诊断疑问的情况。
We studied the diagnostic accuracy of single-photon emission computed tomography (SPECT) with technetium 99m-labeled hexamethylpropylene amine oxime (Tc 99m HMPAO) in 48 patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria and in 60 controls recruited from a population-based study. With logistic regression, we identified decreased temporal regional cerebral blood flow as the best discriminating variable between patients and controls. Receiver-operator characteristic curves showed that the discriminative ability of SPECT improved with increasing dementia severity. With specificity set at 90%, sensitivity figures were 42% in mild, 56% in moderate, and 79% in severe AD. The diagnostic gain as a function of the prior probability of the disease being present was computed for those with mild AD. When the prior probability varied at around 50%, the diagnostic gain for mild AD patients was substantial (a maximum of 34%) for a positive test result but poor for a negative test result. The results suggest that the practical usefulness of SPECT as a diagnostic adjunct in patients suspected of having mild AD is confined to situations in which, on clinical grounds, there is considerable diagnostic doubt.