Suppiah S, Ching S M, Nordin A J, Vinjamuri S
Universiti Putra Malaysia, Faculty of Medicine, Department of Family Medicine, Serdang, Malaysia.
Universiti Putra Malaysia, Faculty of Medicine, Centre for Diagnostic Nuclear Imaging, Serdang, Malaysia.
Med J Malaysia. 2018 Jun;73(3):141-146.
Imaging such as Tc99m-HMPAO single photon emission computed tomography (SPECT), and positron emission tomography/ computed tomography (PET/CT) amyloid scans are used to aid the diagnosis of Alzheimer's disease (AD).
We aimed to correlate the ability of these modalities to differentiate Probable AD and Possible AD using the clinical diagnosis as a gold standard. We also investigated the correlation of severity of amyloid deposit in the brain with the diagnosis of AD.
A retrospective study of 47 subjects (17 Probable AD and 30 Possible AD) who were referred for PET/CT amyloid scans to our centre was conducted. Hypoperfusion in the temporo-parietal lobes on Tc99m-HMPAO SPECT and loss of grey-white matter contrast in cortical regions on PET/CT Amyloid scans indicating the presence of amyloid β deposit were qualitatively interpreted as positive for AD. SPECT and PET/CT were also read in combination (Combo reading). The severity of amyloid β deposit was semiquantitatively assessed in a visual binary method using a scale of Grade 0-4. The severity of amyloid β deposit was assessed in a visual binary method and a semi-quantitative method using a scale of Grade 0-4.
There was significant correlation of Tc99m-HMPAO SPECT, PET/CT amyloid findings and Combo reading with AD. The sensitivity, specificity, PPV and NPV were 87.5%, 73.7%, 58.3% and 93.3% (SPECT); 62.5%, 77.4%, 58.8% and 80.0% (PET/CT) and 87.5%, 84.2%, 70.0% and 30.0% (Combo reading) respectively. The grade of amyloid deposition was not significantly correlated with AD (Spearman's correlation, p=0.687).
There is an incremental benefit in utilizing PET/CT amyloid imaging in cases with atypical presentation and indeterminate findings on conventional imaging of Alzheimer's disease.
诸如锝99m - HMPAO单光子发射计算机断层扫描（SPECT）以及正电子发射断层扫描/计算机断层扫描（PET/CT）淀粉样蛋白扫描等成像技术被用于辅助阿尔茨海默病（AD）的诊断。
我们旨在以临床诊断作为金标准，关联这些检查方式鉴别可能的AD和疑似的AD的能力。我们还研究了脑内淀粉样蛋白沉积的严重程度与AD诊断之间的相关性。
对47名被转诊至我们中心进行PET/CT淀粉样蛋白扫描的受试者（17名可能的AD患者和30名疑似的AD患者）进行了一项回顾性研究。将锝99m - HMPAO SPECT上颞顶叶的灌注不足以及PET/CT淀粉样蛋白扫描上皮质区域灰白质对比度的丧失（表明存在淀粉样β蛋白沉积）定性解释为AD阳性。SPECT和PET/CT也进行联合解读（联合解读）。使用0 - 4级量表，通过视觉二分法对淀粉样β蛋白沉积的严重程度进行半定量评估。淀粉样β蛋白沉积的严重程度通过视觉二分法和使用0 - 4级量表的半定量方法进行评估。
锝99m - HMPAO SPECT、PET/CT淀粉样蛋白检查结果以及联合解读与AD之间存在显著相关性。敏感性、特异性、阳性预测值和阴性预测值分别为87.5%、73.7%、58.3%和93.3%（SPECT）；62.5%、77.4%、58.8%和80.0%（PET/CT）以及87.5%、84.2%、70.0%和30.0%（联合解读）。淀粉样蛋白沉积分级与AD无显著相关性（斯皮尔曼相关性，p = 0.687）。
对于阿尔茨海默病非典型表现且传统成像结果不确定的病例，使用PET/CT淀粉样蛋白成像具有额外的益处。
