Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and.
J Nucl Med. 2024 Oct 1;65(10):1652-1657. doi: 10.2967/jnumed.124.267784.
Methods to shorten [F]FDG Patlak PET imaging procedures ranging from 65-90 to 20-30 min after injection, using a population-averaged input function (PIF) scaled to patient-specific image-derived input function (IDIF) values, were recently evaluated. The aim of the present study was to explore the feasibility of ultrashort 10-min [F]FDG Patlak imaging at 55-65 min after injection using a PIF combined with direct Patlak reconstructions to provide reliable quantitative accuracy of lung tumor uptake, compared with a full-duration 65-min acquisition using an IDIF. Patients underwent a 65-min dynamic PET acquisition on a long-axial-field-of-view (LAFOV) Biograph Vision Quadra PET/CT scanner. Subsequently, direct Patlak reconstructions and image-based (with reconstructed dynamic images) Patlak analyses were performed using both the IDIF (time to relative kinetic equilibrium between blood and tissue concentration (t*) = 30 min) and a scaled PIF at 30-60 min after injection. Next, direct Patlak reconstructions were performed on the system console using only the last 10 min of the acquisition, that is, from 55 to 65 min after injection, and a scaled PIF using maximum crystal ring difference settings of both 85 and 322. Tumor lesion and healthy-tissue uptake was quantified and compared between the differently obtained parametric images to assess quantitative accuracy. Good agreement was obtained between direct- and image-based Patlak analyses using the IDIF (t* = 30 min) and scaled PIF at 30-60 min after injection, performed using the different approaches, with no more than 8.8% deviation in tumor influx rate value ( ) (mean difference ranging from -0.0022 to 0.0018 mL/[min × g]). When direct Patlak reconstruction was performed on the system console, excellent agreement was found between the use of a scaled PIF at 30-60 min after injection versus 55-65 min after injection, with 2.4% deviation in tumor (median difference, -0.0018 mL/[min × g]; range, -0.0047 to 0.0036 mL/[min × g]). For different maximum crystal ring difference settings using the scan time interval of 55-65 min after injection, only a 0.5% difference (median difference, 0.0000 mL/[min × g]; range, -0.0004 to 0.0013 mL/[min × g]) in tumor was found. Ultrashort whole-body [F]FDG Patlak imaging is feasible on an LAFOV Biograph Vision Quadra PET/CT system without loss of quantitative accuracy to assess lung tumor uptake compared with a full-duration 65-min acquisition. The ultrashort 10-min direct Patlak reconstruction with PIF allows for its implementation in clinical practice.
方法从 65-90 分钟缩短到注射后 20-30 分钟，使用平均人群输入函数（PIF）缩放到患者特定的图像衍生输入函数（IDIF）值，最近进行了评估。本研究的目的是探索使用 PIF 进行超短的 10 分钟 [F]FDG Patlak 成像的可行性，即在注射后 55-65 分钟进行，使用直接 Patlak 重建以提供可靠的肺肿瘤摄取的定量准确性，与使用 IDIF 进行全长 65 分钟采集相比。患者在长轴向视野（LAFOV）Biograph Vision Quadra PET/CT 扫描仪上进行 65 分钟动态 PET 采集。随后，使用 IDIF（血与组织浓度相对动力学平衡时间（t*）=30 分钟）和注射后 30-60 分钟的缩放 PIF 进行直接 Patlak 重建和基于图像的（使用动态图像重建）Patlak 分析。接下来，仅在采集的最后 10 分钟（即注射后 55-65 分钟）使用系统控制台进行直接 Patlak 重建，并使用最大晶体环差异设置为 85 和 322 进行缩放 PIF。量化并比较不同方法获得的参数图像中的肿瘤病变和健康组织摄取，以评估定量准确性。使用 IDIF（t*=30 分钟）和注射后 30-60 分钟的缩放 PIF 进行直接和基于图像的 Patlak 分析之间得到了很好的一致性，使用不同的方法，肿瘤流入率值（）的偏差不超过 8.8%（平均差异范围为-0.0022 至 0.0018 mL/[min×g]）。当在系统控制台进行直接 Patlak 重建时，使用注射后 30-60 分钟与 55-65 分钟的缩放 PIF 之间发现了极好的一致性，肿瘤的偏差为 2.4%（中位数差异，-0.0018 mL/[min×g]；范围，-0.0047 至 0.0036 mL/[min×g]）。对于使用 55-65 分钟后扫描时间间隔的不同最大晶体环差异设置，仅发现肿瘤的差异为 0.5%（中位数差异，0.0000 mL/[min×g]；范围，-0.0004 至 0.0013 mL/[min×g]）。LAFOV Biograph Vision Quadra PET/CT 系统上的超短全身 [F]FDG Patlak 成像可行，与全长 65 分钟采集相比，无需定量准确性损失即可评估肺肿瘤摄取。使用 PIF 的超短 10 分钟直接 Patlak 重建允许其在临床实践中实施。
