Department of Nuclear Medicine, Peking University First Hospital, No.8, Xishiku St., West District, Beijing, 100034, People's Republic of China.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kinshighway Blvd., Campus Box 8225, St Louis, MO 63110, United States of America.
Phys Med Biol. 2021 Mar 12;66(6):064005. doi: 10.1088/1361-6560/abe83b.
F-FDG uptake rate constant K is the main physiology parameter measured in dynamic PET studies. A model-independent graphical analysis using Patlak plot with plasma input function (PIF) is a standard approach used to estimate K . The PIF is the F-FDG time activity curve (TAC) in plasma that is obtained by serial arterial blood sampling. The purpose of the study is to evaluate a Patlak plot-based optimization approach with reduced blood samples for noninvasive quantification of dynamic F-FDG PET imaging. Eight 60 min rhesus monkey brain dynamic F-FDG PET scans with arterial blood samples were collected. The measured PIF (mPIF) was determined by arterial blood samples. TACs of seven cerebral regions of interest were generated from each study. With a given number of blood samples, the population-based PIF (pPIF) was determined by either interpolation or extrapolation method using scale calibrated population mean of normalized PIF. The optimal sampling scheme with given blood sample size was determined by maximizing the correlations between the K estimated from pPIF and those obtained by mPIF. A leave-two-out cross-validation method was used for evaluation. The linear correlations between the K estimates from pPIF with optimal sampling schemes and those from mPIF were: K (pPIF 1 sample at 40 min) = 1.015 K (mPIF) - 0.000, R = 0.974; K (pPIF 2 samples at 35 and 50 min) = 1.052 K (mPIF) - 0.001, R = 0.976; K (pPIF 3 samples at 12, 40, and 50 min) = 1.030 K (mPIF) - 0.000, R = 0.985; and K (pPIF 4 samples at 10, 20, 40, and 50 min) = 1.016 K (mPIF)- 0.000, R = 0.993. As the sample size became greater or equal to 4, the K estimates from pPIF with the optimal protocol were almost identical to those from mPIF. The Patlak plot-based optimization approach is a reliable method to estimate PIF for noninvasive quantification of non-human primate dynamic F-FDG PET imaging and is potentially extendable to further translational human studies.
氟代脱氧葡萄糖摄取率常数 K 是动态 PET 研究中测量的主要生理学参数。使用带有血浆输入函数 (PIF) 的 Patlak 图进行无模型图形分析是一种标准方法，用于估计 K。PIF 是血浆中的 F-FDG 时间活性曲线 (TAC)，通过连续动脉采血获得。该研究的目的是评估一种基于 Patlak 图的优化方法，该方法使用较少的血样进行无创定量动态 F-FDG PET 成像。收集了 8 只恒河猴大脑 60 分钟动态 F-FDG PET 扫描的动脉血样。通过动脉血样测定测量的 PIF（mPIF）。从每项研究中生成 7 个感兴趣脑区的 TAC。在给定的血样数量下，通过使用标准化 PIF 的群体均值进行插值或外推，确定基于群体的 PIF（pPIF）。通过最大化从 pPIF 估计的 K 与从 mPIF 获得的 K 之间的相关性，确定具有给定血样量的最佳采样方案。使用两次抽样交叉验证方法进行评估。从具有最佳采样方案的 pPIF 获得的 K 估计值与从 mPIF 获得的 K 估计值之间的线性相关性为：K（pPIF 40 分钟时的 1 个样本）= 1.015 K（mPIF）-0.000，R=0.974；K（pPIF 35 分钟和 50 分钟时的 2 个样本）= 1.052 K（mPIF）-0.001，R=0.976；K（pPIF 12 分钟、40 分钟和 50 分钟时的 3 个样本）= 1.030 K（mPIF）-0.000，R=0.985；K（pPIF 10 分钟、20 分钟、40 分钟和 50 分钟时的 4 个样本）= 1.016 K（mPIF）-0.000，R=0.993。随着样本量增加到 4 个或更多，从最佳方案的 pPIF 获得的 K 估计值与从 mPIF 获得的 K 估计值几乎相同。基于 Patlak 图的优化方法是一种可靠的方法，用于估计非人类灵长类动物动态 F-FDG PET 成像的无创定量 PIF，并且可能扩展到进一步的转化人类研究。
