Doisy College of Health Sciences, Saint Louis University, St. Louis, Missouri
Doisy College of Health Sciences, Saint Louis University, St. Louis, Missouri.
J Nucl Med Technol. 2020 Dec;48(4):354-360. doi: 10.2967/jnmt.120.244160. Epub 2020 Sep 4.
The digital PET/CT scanner with digital photon-counting technique promises a shorter scan time, improved small-lesion detectability, and reduced radiation dose for the PET and CT portions of the exam while improving image quality. In this single-institution retrospective review study, 84 participants who had undergone PET/CT on both analog and digital scanners were analyzed. The aim was to evaluate the impact of image field of view (FOV) and body mass index (BMI) on the digital compared with the analog PET/CT scanners. The participants were categorized into different groups based on their BMI. Total scan times, F-FDG doses, and dose-length products (DLP) were collected and compared. Image quality was also assessed by certified nuclear medicine physicians and graded on a scale from 1 to 5. In the skull-to-mid-thigh FOVs, the digital scanner had a scan time shorter by 37% ( 0.001), a F-FDG dose lower by 16% ( 0.001), but only an 8% reduction in DLP ( 0.2). In the head-to-toe FOV cases, the digital scanner showed reductions in scan time (33%; 0.001), F-FDG dose (13%; 0.001), and DLP (19%; 0.001). When BMI was accounted for, the digital scanner had a scan time shorter by 33% ( 0.001), as well as a reduced DLP ( 0.001) and F-FDG dose ( 0.001), with the most prominent changes being in the overweight and obese participants. Image quality was also improved by the digital scanner, with a score of 4.5, versus 4.0 for the analog scanner. The digital scanner has a shorter scan time and lower DLP, requires a lower F-FDG dose, and provides improved image quality when compared with the analog scanner. The most impactful difference in scan time, DLP, and F-FDG dose were observed in obese and overweight participants.
数字 PET/CT 扫描仪采用数字光子计数技术，有望缩短扫描时间，提高小病灶的探测能力，降低 PET 和 CT 部分的辐射剂量，同时提高图像质量。在这项单中心回顾性研究中，对 84 名在模拟和数字扫描仪上均进行过 PET/CT 的参与者进行了分析。目的是评估图像视野（FOV）和体重指数（BMI）对数字与模拟 PET/CT 扫描仪的影响。根据 BMI 将参与者分为不同的组。收集并比较总扫描时间、F-FDG 剂量和剂量长度乘积（DLP）。图像质量也由核医学医师进行评估，并按 1 到 5 分进行分级。在从头颅到大腿中段的 FOV 中，数字扫描仪的扫描时间缩短了 37%（ 0.001），F-FDG 剂量降低了 16%（ 0.001），但 DLP 仅降低了 8%（ 0.2）。在从头到脚的 FOV 情况下，数字扫描仪的扫描时间（33%； 0.001）、F-FDG 剂量（13%； 0.001）和 DLP（19%； 0.001）均减少。当考虑 BMI 时，数字扫描仪的扫描时间缩短了 33%（ 0.001），DLP 降低（ 0.001）和 F-FDG 剂量降低（ 0.001），超重和肥胖参与者的变化最为明显。数字扫描仪还提高了图像质量，评分为 4.5，而模拟扫描仪的评分为 4.0。与模拟扫描仪相比，数字扫描仪的扫描时间更短，DLP 更低，F-FDG 剂量更低，并且提供了更高的图像质量。在肥胖和超重参与者中，扫描时间、DLP 和 F-FDG 剂量的差异最为显著。
