Chung Kevin J, Chaudhari Abhijit J, Nardo Lorenzo, Jones Terry, Chen Moon S, Badawi Ramsey D, Cherry Simon R, Wang Guobao
Department of Radiology, University of California Davis Health, Sacramento, California;
Department of Radiology, University of California Davis Health, Sacramento, California.
J Nucl Med. 2025 Jun 2;66(6):973-980. doi: 10.2967/jnumed.124.268706.
Past efforts to measure blood flow with the widely available radiotracer F-FDG were limited to tissues with high F-FDG extraction fraction. In this study, we developed an early dynamic F-FDG PET method with high-temporal-resolution (HTR) kinetic modeling to assess total-body blood flow based on deriving the vascular phase of F-FDG transit and conducted a pilot comparison study against a C-butanol flow-tracer reference. The first 2 min of dynamic PET scans were reconstructed at HTR (60 × 1 s/frame, 30 × 2 s/frame) to resolve the rapid passage of the radiotracer through blood vessels. In contrast to existing methods that use blood-to-tissue transport rate as a surrogate of blood flow, our method directly estimated blood flow using a distributed kinetic model (adiabatic approximation to tissue homogeneity [AATH] model). To validate our F-FDG measurements of blood flow against a reference flow-specific radiotracer, we analyzed total-body dynamic PET images of 6 human participants scanned with both F-FDG and C-butanol. An additional 34 total-body dynamic F-FDG PET images of healthy participants were analyzed for comparison against published blood-flow ranges. Regional blood flow was estimated across the body, and total-body parametric imaging of blood flow was conducted for visual assessment. AATH and standard compartment model fitting was compared using the Akaike information criterion at different temporal resolutions. F-FDG blood flow was in quantitative agreement with flow measured from C-butanol across same-subject regional measurements (Pearson correlation coefficient, 0.955; < 0.001; linear regression slope and intercept, 0.973 and -0.012, respectively), which was visually corroborated by total-body blood-flow parametric imaging. Our method resolved a wide range of blood-flow values across the body in broad agreement with published ranges (e.g., healthy cohort values of 0.51 ± 0.12 mL/min/cm in the cerebral cortex and 2.03 ± 0.64 mL/min/cm in the lungs). HTR (1-2 s/frame) was required for AATH modeling. Total-body blood-flow imaging was feasible using early dynamic F-FDG PET with HTR kinetic modeling. This method may be combined with standard F-FDG PET methods to enable efficient single-tracer multiparametric flow-metabolism imaging, with numerous research and clinical applications in oncology, cardiovascular disease, pain medicine, and neuroscience.
过去利用广泛可用的放射性示踪剂F-FDG测量血流的努力仅限于F-FDG摄取分数高的组织。在本研究中，我们开发了一种具有高时间分辨率（HTR）动力学建模的早期动态F-FDG PET方法，通过推导F-FDG通过血管的时相来评估全身血流，并与C-丁醇血流示踪剂参考进行了初步比较研究。动态PET扫描的前2分钟以高时间分辨率（60×1秒/帧，30×2秒/帧）重建，以解析放射性示踪剂在血管中的快速通过。与使用血-组织转运速率作为血流替代指标的现有方法不同，我们的方法使用分布式动力学模型（组织均匀性绝热近似[AATH]模型）直接估计血流。为了对照参考血流特异性放射性示踪剂验证我们对血流的F-FDG测量结果，我们分析了6名同时用F-FDG和C-丁醇扫描的人类参与者的全身动态PET图像。另外分析了34名健康参与者的全身动态F-FDG PET图像，以与已发表的血流范围进行比较。估计了全身的区域血流，并进行了全身血流参数成像以进行视觉评估。在不同时间分辨率下使用赤池信息准则比较了AATH和标准房室模型拟合。F-FDG血流与同一受试者区域测量中从C-丁醇测得的血流在定量上一致（皮尔逊相关系数，0.955；<0.001；线性回归斜率和截距分别为0.973和-0.012），全身血流参数成像在视觉上证实了这一点。我们的方法解析了全身范围内广泛的血流值，与已发表的范围大致一致（例如，大脑皮层中健康队列的值为0.51±0.12毫升/分钟/平方厘米，肺中为2.03±0.64毫升/分钟/平方厘米）。AATH建模需要高时间分辨率（1-2秒/帧）。使用具有HTR动力学建模的早期动态F-FDG PET进行全身血流成像可行。该方法可与标准F-FDG PET方法结合，实现高效的单示踪剂多参数血流-代谢成像，在肿瘤学、心血管疾病、疼痛医学和神经科学中有众多研究和临床应用。
