Samimi Rezvan, Kamali-Asl Alireza, Geramifar Parham, van den Hoff Jörg, Rahmim Arman
Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran.
Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran.
Phys Med. 2020 Dec;80:193-200. doi: 10.1016/j.ejmp.2020.11.004. Epub 2020 Nov 11.
We aimed to investigate whether short dynamic PET imaging started at injection, complemented with routine clinical acquisition at 60-min post-injection (static), can achieve reliable kinetic analysis.
Dynamic and static 18F-2-fluoro-2-deoxy-D-glucose (FDG) PET data were generated using realistic simulations to assess uncertainties due to statistical noise as well as bias. Following image reconstructions, kinetic parameters obtained from a 2-tissue-compartmental model (2TCM) were estimated, making use of the static image, and the time duration of dynamic PET data were incrementally shortened. We also investigated, in the first 2-min, different frame sampling rates, towards optimized dynamic PET imaging. Kinetic parameters from shortened dynamic datasets were additionally estimated for 9 patients (15 scans) with liver metastases of colorectal cancer, and were compared with those derived from full dynamic imaging using correlation and Passing-Bablok regression analyses.
The results showed that by reduction of dynamic scan times from 60-min to as short as 5-min, while using static data at 60-min post-injection, bias and variability stayed comparable in estimated kinetic parameters. Early frame samplings of 5, 24 and 30 s yielded highest biases compared to other schemes. An early frame sampling of 10 s generally kept both bias and variability to a minimum. In clinical studies, strong correlation (r ≥ 0.97, P < 0.0001) existed between all kinetic parameters in full vs. shortened scan protocols.
Shortened 5-min dynamic scan, sampled as 12 × 10 + 6 × 30 s, followed by 3-min static image at 60-min post-injection, enables accurate and robust estimation of 2TCM parameters, while enabling generation of SUV estimates.
我们旨在研究从注射开始的短动态PET成像，辅以注射后60分钟的常规临床采集（静态），是否能够实现可靠的动力学分析。
使用真实模拟生成动态和静态18F-2-氟-2-脱氧-D-葡萄糖（FDG）PET数据，以评估统计噪声和偏差引起的不确定性。图像重建后，利用静态图像估计从双组织室模型（2TCM）获得的动力学参数，并逐步缩短动态PET数据的持续时间。我们还在前2分钟内研究了不同的帧采样率，以优化动态PET成像。另外对9例结直肠癌肝转移患者（15次扫描）缩短的动态数据集的动力学参数进行了估计，并使用相关性分析和Passing-Bablok回归分析将其与全动态成像得出的参数进行比较。
结果表明，将动态扫描时间从60分钟缩短至短至5分钟，同时使用注射后60分钟的静态数据时，估计的动力学参数中的偏差和变异性保持相当。与其他方案相比，5、24和30秒的早期帧采样产生的偏差最大。10秒的早期帧采样通常将偏差和变异性都保持在最低水平。在临床研究中，全扫描与缩短扫描方案的所有动力学参数之间存在强相关性（r≥0.97，P<0.0001）。
缩短为5分钟的动态扫描，采样为12×10 + 6×30秒，随后在注射后60分钟进行3分钟的静态图像采集，能够准确且稳健地估计2TCM参数，同时能够生成SUV估计值。
