Institute of Neuroscience, Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, United Kingdom.
Institute of Neuroscience, Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, United Kingdom; Nuclear Medicine Department, Royal Victoria Infirmary, Newcastle upon Tyne NHS Foundation Hospitals Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, United Kingdom.
Parkinsonism Relat Disord. 2019 May;62:79-84. doi: 10.1016/j.parkreldis.2019.01.024. Epub 2019 Jan 26.
To determine the utility of I-metaiodobenzylguanidine cardiac scintigraphy (MIBG), and optimum heart: mediastinum ratio (HMR) for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) in a clinically representative population, comparing findings with those of I-2β -carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) SPECT.
We recruited subjects with probable DLB (n = 17) and probable AD (n = 16) from clinical services. Each participant underwent clinical examination, cardiac MIBG scintigraphy and FP-CIT SPECT. Diagnosis was made on the basis of clinical symptoms using validated criteria. Cardiac MIBG uptake was measured by the planar HMR, blind to clinical diagnosis, with values below a cut-off taken from a previous study (<2.2 at four hours) defining scans as abnormal. FP-CIT scans were blindly rated according to a visual rating scale.
MIBG had a sensitivity, specificity and overall accuracy of 71%, 81% and 76% for distinguishing DLB from AD. FP-CIT demonstrated a sensitivity, specificity and accuracy of 82%, 88% and 85%. Using a lower HMR cut-off to distinguish between abnormal and normal MIBG scans improved the accuracy of MIBG, raising specificity (100%) and overall accuracy (85%) without compromising sensitivity (71%). Neither prescription of potentially interfering medications, nor a history of myocardial infarction (MI), had a significant effect on HMR.
We found that MIBG did not demonstrate superior sensitivity and overall accuracy to FP-CIT. HMR cut-off influences biomarker utility, and clinical and Caucasian populations may require a lower cut-off than those reported elsewhere. Future MIBG studies should include clinically representative cohorts as neither medications nor previous MI appear to influence HMR.
在一个具有代表性的临床人群中，通过比较碘代间位碘苄胍（MIBG）心脏闪烁显像和碘-2β- 碳甲氧基-3β-（4-碘苯基）-N-（3-氟丙基）去甲托烷（FP-CIT）SPECT，确定其用于鉴别路易体痴呆（DLB）与阿尔茨海默病（AD）的效用和最佳心脏：纵隔比（HMR）。
我们从临床科室招募了可能患有 DLB（n=17）和 AD（n=16）的受试者。每位参与者都接受了临床检查、心脏 MIBG 闪烁显像和 FP-CIT SPECT。根据经过验证的标准，根据临床症状做出诊断。采用以前的研究中确定的截断值（<2.2 时在 4 小时）来测量心脏 MIBG 摄取的 HMR，即低于截断值的平面 HMR 定义为异常。根据视觉评分量表对 FP-CIT 扫描进行盲法评分。
MIBG 用于区分 DLB 和 AD 的敏感性、特异性和总准确性分别为 71%、81%和 76%。FP-CIT 的敏感性、特异性和准确性分别为 82%、88%和 85%。使用较低的 HMR 截断值来区分异常和正常的 MIBG 扫描可以提高 MIBG 的准确性，提高特异性（100%）和总准确性（85%）而不降低敏感性（71%）。潜在干扰药物的处方或心肌梗死（MI）病史对 HMR 均无显著影响。
我们发现 MIBG 与 FP-CIT 相比，敏感性和总准确性均无优势。HMR 截断值影响生物标志物的效用，临床和白种人群可能需要比其他地方报道的更低的截断值。未来的 MIBG 研究应包括具有代表性的临床队列，因为药物和既往 MI 似乎均不影响 HMR。
