UNASSIGNED: The method is tested on a multi-site dataset containing 177 PET studies from two TSPO tracers ([11C]PBR28 and [18F]DPA714). Firstly, 1T1K-IDIF K1 estimates were compared in terms of both bias and correlation with standard kinetic methodology. Then, the method was tested on an independent sample of [11C]PBR28 scans before and after inflammatory interferon-α challenge, and on test-retest dataset of [18F]DPA714 scans.
UNASSIGNED: Comparison with standard kinetic methodology showed good-to-excellent intra-subject correlation for regional 1T1K-IDIF-K1 (ρintra = 0.93 ± 0.08), although the bias was variable depending on IDIF ability to approximate blood input functions (0.03-0.39 mL/cm3/min). 1T1K-IDIF-K1 unveiled a significant reduction of BBB permeability after inflammatory interferon-α challenge, replicating results from standard quantification. High intra-subject correlation (ρ = 0.97 ± 0.01) was reported between K1 estimates of test and retest scans.
UNASSIGNED: This evidence supports 1T1K-IDIF as blood-free alternative to assess TSPO tracers\' unidirectional blood brain clearance. K1 investigation could complement more traditional measures in TSPO studies, and even allow further mechanistic insight in the interpretation of TSPO signal.
■在包含来自两种TSPO示踪剂([11C]PBR28和[18F]DPA714)的177项PET研究的多位点数据集上测试了该方法。首先,1T1K-IDIFK1估计值在偏倚和相关性方面与标准动力学方法进行了比较。然后,该方法在炎性干扰素-α攻击前后的[11C]PBR28扫描的独立样本上进行了测试,以及[18F]DPA714扫描的测试-重测数据集。
■与标准动力学方法的比较显示,区域1T1K-IDIF-K1(ρintra=0.93±0.08)的受试者内相关性良好,尽管偏倚取决于IDIF对血液输入功能的近似能力(0.03-0.39mL/cm3/min)。1T1K-IDIF-K1揭示了炎症干扰素-α攻击后BBB通透性的显著降低,从标准定量复制结果。在测试和重新测试扫描的K1估计之间报告了高的受试者内相关性(ρ=0.97±0.01)。
■该证据支持1T1K-IDIF作为无血替代品来评估TSPO示踪剂\'单向血脑清除。K1调查可以补充TSPO研究中更传统的措施,甚至允许在TSPO信号的解释中进一步的机械洞察。