Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology and Nuclear Medicine, Amsterdam Neuroscience, De Boelelaan 1117, Amsterdam, The Netherlands.
Imaging Division, Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands.
Mol Imaging Biol. 2021 Jun;23(3):335-339. doi: 10.1007/s11307-021-01606-z. Epub 2021 Apr 21.
Moderate-to-high correlations have been reported between the [C]PiB PET-derived relative tracer delivery rate R and relative CBF as measured using [O]HO PET, supporting its use as a proxy of relative CBF. As longitudinal PET studies become more common for measuring treatment efficacy or disease progression, it is important to know the intrinsic variability of R. The purpose of the present study was to determine this through a retrospective data analysis.
Test-retest data belonging to twelve participants, who underwent two 90 min [C]PiB PET scans, were retrospectively included. The voxel-based implementation of the two-step simplified reference tissue model with cerebellar grey matter as reference tissue was used to compute R images. Next, test-retest variability was calculated, and test and retest R measures were compared using linear mixed effect models and a Bland-Altman analysis.
Test-retest variability was low across regions (max. 5.8 %), and test and retest measures showed high, significant correlations (R=0.92, slope=0.98) and a negligible bias (0.69±3.07 %).
In conclusion, the high precision of [C]PiB R suggests suitable applicability for cross-sectional and longitudinal studies.
[C]PiB PET 衍生的相对示踪剂输送率 R 与 [O]HO PET 测量的相对 CBF 之间存在中度至高度相关性，支持其作为相对 CBF 的替代指标。随着用于测量治疗效果或疾病进展的纵向 PET 研究变得越来越普遍，了解 R 的固有变异性非常重要。本研究的目的是通过回顾性数据分析来确定这一点。
回顾性纳入了 12 名参与者的两次 90 分钟 [C]PiB PET 扫描的测试-重测数据。使用两步简化参考组织模型的基于体素的实施，以小脑灰质为参考组织，计算 R 图像。接下来，计算了测试-重测变异性，并使用线性混合效应模型和 Bland-Altman 分析比较了测试和重测 R 测量值。
各区域的测试-重测变异性较低（最高 5.8%），测试和重测测量值之间存在高度显著的相关性（R=0.92，斜率=0.98）和可忽略的偏差（0.69±3.07%）。
总之，[C]PiB R 的高精度表明其适用于横断面和纵向研究。
