Nai Ying-Hwey, Watanuki Shoichi, Tashiro Manabu, Okamura Nobuyuki, Watabe Hiroshi
Division of Radiation Informatics for Medical Imaging, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.
Division of Radiation Protection and Safety Control, Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan.
Radiol Phys Technol. 2018 Dec;11(4):451-459. doi: 10.1007/s12194-018-0485-y. Epub 2018 Oct 16.
With the increasing incidence of dementia worldwide, the frequent use of amyloid and tau positron emission tomography imaging requires low-dose protocols for the differential diagnoses of various neurodegenerative diseases and the monitoring of disease progression. In this study, we investigated the feasibility to reduce the PET dose without a significant loss of quantitative accuracy in 3D dynamic row action maximum likelihood algorithm-reconstructed PET images using [C]PIB and [F]THK5351. Eighteen cognitively normal young controls, cognitively normal elderly controls, and patients with probable Alzheimer's disease (n = 6 each), were included. Reduced doses were simulated by randomly sampling half and quarter of the full counts in list mode data for one independent realization at each simulated dose. Bias was evaluated between the reduced dose from the full dose of standardized uptake value ratio (SUVR), distribution volume ratio (DVR) from reference Logan, and non-displaceable binding potential (BP) from simplified reference tissue model (SRTM). DVR yielded the least bias at low dose compared to SUVR and BP, and thus, is highly recommended. The dose of [F]THK5351 and [C]PIB can be reduced to a quarter of the full dose using DVR for evaluation, whereas the dose can only be reduced to half and a quarter of the full dose for [F]THK5351 and [C]PIB using SUVR. BP showed inconsistent trend and large bias at low dose. The feasibility of dose reduction was dependent on the selected parameters of interest, reconstruction algorithms, reference regions, and to a lesser degree by motion effects.
随着全球痴呆症发病率的上升，淀粉样蛋白和tau正电子发射断层扫描成像的频繁使用需要低剂量方案来鉴别各种神经退行性疾病并监测疾病进展。在本研究中，我们使用[C]PIB和[F]THK5351，研究了在三维动态行动作最大似然算法重建的PET图像中降低PET剂量而不显著损失定量准确性的可行性。纳入了18名认知正常的年轻对照者、认知正常的老年对照者以及可能患有阿尔茨海默病的患者（每组n = 6）。通过在列表模式数据中随机抽取全计数的一半和四分之一来模拟降低剂量，以在每个模拟剂量下进行一次独立实现。评估了全剂量标准化摄取值比率（SUVR）、参考洛根分布容积比率（DVR）以及简化参考组织模型（SRTM）的不可置换结合潜力（BP）与降低剂量之间的偏差。与SUVR和BP相比，DVR在低剂量时产生的偏差最小，因此强烈推荐使用。使用DVR进行评估时，[F]THK5351和[C]PIB的剂量可降低至全剂量的四分之一，而使用SUVR时，[F]THK5351和[C]PIB的剂量只能分别降低至全剂量的一半和四分之一。BP在低剂量时显示出不一致的趋势和较大偏差。剂量降低的可行性取决于所选的感兴趣参数、重建算法、参考区域，并且在较小程度上取决于运动效应。
