UNASSIGNED: One-hundred-thirteen head-to-head FBP-PiB scan pairs, scanned from the same subject within ninety days, were selected from the Open Access Series of Imaging Studies 3 (OASIS-3) dataset. The Centiloid scale, ComBat with no covariates, ComBat with biological covariates, and GAM-ComBat with biological covariates were used to harmonize both global and regional amyloid standardized uptake value ratios (SUVR). Intraclass correlation coefficient (ICC) and mean standardized absolute error (MsAE) were computed to measure the absolute agreement between tracers. Additionally, longitudinal amyloid SUVRs from an anti-amyloid drug trial were simulated using linear mixed effects modeling. Differences in rates-of-change between simulated treatment and placebo groups were tested, and change in statistical power/Type-I error after harmonization was quantified.
UNASSIGNED: In the head-to-head tracer comparison, the best ICC and MsAE were achieved after harmonizing with ComBat with no covariates for the global summary SUVR. ComBat with no covariates also performed the best in harmonizing regional SUVRs. In the clinical trial simulation, harmonization with both Centiloid and ComBat increased statistical power of detecting true rate-of-change differences between groups and decreased false discovery rate in the absence of a treatment effect. The greatest benefit of harmonization was observed when groups exhibited differing FPB-to-PiB proportions.
UNASSIGNED: ComBat outperformed the Centiloid scale in harmonizing both global and regional amyloid estimates. Additionally, ComBat improved the detection of rate-of-change differences between clinical trial groups. Our findings suggest that ComBat is a viable alternative to Centiloid for harmonizing regional amyloid PET analyses.
■一百一十三个头对头FBP-PiB扫描对,在90天内从同一受试者扫描,选自开放存取系列成像研究3(OASIS-3)数据集。Centiloid量表,没有协变量的ComBat,ComBat与生物协变量,和具有生物协变量的GAM-ComBat用于协调全球和区域淀粉样蛋白标准化摄取值比率(SUVR)。计算组内相关系数(ICC)和平均标准化绝对误差(MsAE)以测量示踪剂之间的绝对一致性。此外,使用线性混合效应模型模拟了来自抗淀粉样蛋白药物试验的纵向淀粉样蛋白SUVRs.测试了模拟治疗组和安慰剂组之间变化率的差异,并量化了统一后的统计功效/I型误差的变化。
■在头对头示踪剂比较中,在与ComBat协调后,获得了最佳ICC和MsAE,而全球汇总SUVR没有协变量.没有协变量的ComBat在协调区域SUVR方面也表现最好。在临床试验模拟中,与Centiloid和ComBat的协调增加了检测组间真实变化率差异的统计能力,并在没有治疗效果的情况下降低了错误发现率。当各组表现出不同的FPB与PiB比例时,观察到协调的最大益处。
■ComBat在协调全球和区域淀粉样蛋白估计方面优于Centiloid量表。此外,ComBat改善了临床试验组之间变化率差异的检测。我们的发现表明,ComBat是Centiloid的可行替代品,可用于协调区域淀粉样蛋白PET分析。