Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.
Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland.
Eur J Nucl Med Mol Imaging. 2021 Jul;48(8):2395-2404. doi: 10.1007/s00259-021-05282-7. Epub 2021 Apr 2.
To investigate the performance of the new long axial field-of-view (LAFOV) Biograph Vision Quadra PET/CT and a standard axial field-of-view (SAFOV) Biograph Vision 600 PET/CT (both: Siemens Healthineers) system using an intra-patient comparison.
Forty-four patients undergoing routine oncological PET/CT were prospectively included and underwent a same-day dual-scanning protocol following a single administration of either F-FDG (n = 20), F-PSMA-1007 (n = 16) or Ga-DOTA-TOC (n = 8). Half the patients first received a clinically routine examination on the SAFOV (FOV 26.3 cm) in continuous bed motion and then immediately afterwards on the LAFOV system (10-min acquisition in list mode, FOV 106 cm); the second half underwent scanning in the reverse order. Comparisons between the LAFOV at different emulated scan times (by rebinning list mode data) and the SAFOV were made for target lesion integral activity, signal to noise (SNR), target lesion to background ratio (TBR) and visual image quality.
Equivalent target lesion integral activity to the SAFOV acquisitions (16-min duration for a 106 cm FOV) were obtained on the LAFOV in 1.63 ± 0.19 min (mean ± standard error). Equivalent SNR was obtained by 1.82 ± 1.00 min LAFOV acquisitions. No statistically significant differences (p > 0.05) in TBR were observed even for 0.5 min LAFOV examinations. Subjective image quality rated by two physicians confirmed the 10 min LAFOV to be of the highest quality, with equivalence between the LAFOV and the SAFOV at 1.8 ± 0.85 min. By analogy, if the LAFOV scans were maintained at 10 min, proportional reductions in applied radiopharmaceutical could obtain equivalent lesion integral activity for activities under 40 MBq and equivalent doses for the PET component of <1 mSv.
Improved image quality, lesion quantification and SNR resulting from higher sensitivity were demonstrated for an LAFOV system in a head-to-head comparison under clinical conditions. The LAFOV system could deliver images of comparable quality and lesion quantification in under 2 min, compared to routine SAFOV acquisition (16 min for equivalent FOV coverage). Alternatively, the LAFOV system could allow for low-dose examination protocols. Shorter LAFOV acquisitions (0.5 min), while of lower visual quality and SNR, were of adequate quality with respect to target lesion identification, suggesting that ultra-fast or low-dose acquisitions can be acceptable in selected settings.
使用患者内对照研究，比较新型长轴向视野（LAFOV）Biograph Vision Quadra PET/CT 和标准轴向视野（SAFOV）Biograph Vision 600 PET/CT（均来自西门子医疗）系统的性能。
前瞻性纳入 44 例行常规肿瘤 PET/CT 检查的患者，在单次给药 F-FDG（n=20）、F-PSMA-1007（n=16）或 Ga-DOTA-TOC（n=8）后，进行同日双扫描方案。一半患者首先在连续床动模式下接受 SAFOV（FOV 26.3 cm）的临床常规检查，然后立即在 LAFOV 系统上进行检查（10 分钟采集，FOV 106 cm；列表模式重排）；另一半患者以相反的顺序进行扫描。比较了不同模拟扫描时间（通过列表模式数据重排）的 LAFOV 与 SAFOV 的靶病变积分活动、信号噪声比（SNR）、靶病变与背景比（TBR）和视觉图像质量。
在 LAFOV 上以 1.63±0.19 分钟（平均值±标准误差）获得与 SAFOV 采集等效的靶病变积分活动（106 cm FOV 的 16 分钟持续时间）。以 1.82±1.00 分钟 LAFOV 采集获得等效 SNR。即使 LAFOV 检查时间为 0.5 分钟，TBR 也无统计学差异（p>0.05）。两位医生主观评估的图像质量证实，10 分钟 LAFOV 的质量最高，LAFOV 与 1.8±0.85 分钟的 SAFOV 相当。类似地，如果 LAFOV 扫描保持 10 分钟，则在放射性药物应用量减少的情况下，仍可获得低于 40 MBq 的活动的等效病变积分活动，且 PET 成分的等效剂量低于 1 mSv。
在临床条件下，对头对头比较，LAFOV 系统显示出更高的灵敏度、改善的图像质量、病变定量和 SNR。LAFOV 系统可在不到 2 分钟的时间内提供与常规 SAFOV 采集（16 分钟用于等效 FOV 覆盖）相当的图像质量和病变定量。或者，LAFOV 系统可允许进行低剂量检查方案。虽然较短的 LAFOV 采集（0.5 分钟）的视觉质量和 SNR 较低，但在靶病变识别方面具有足够的质量，表明在某些情况下可以接受超快速或低剂量采集。
