Purpose

Current European Association of Nuclear Medicine (EANM) Research Ltd. (EARL) guidelines for the standardisation of PET imaging developed for conventional systems have not yet been adjusted for long axial field-of-view (LAFOV) systems. In order to use the LAFOV Siemens Biograph Vision Quadra PET/CT (Siemens Healthineers, Knoxville, TN, USA) in multicentre research and harmonised clinical use, compliance to EARL specifications for ¹⁸F-FDG tumour imaging was explored in the current study. Additional tests at various locations throughout the LAFOV and the use of shorter scan durations were included. Furthermore, clinical data were collected to further explore and validate the effects of reducing scan duration on semi-quantitative PET image biomarker accuracy and precision when using EARL-compliant reconstruction settings.

Methods

EARL compliance phantom measurements were performed using the NEMA image quality phantom both in the centre and at various locations throughout the LAFOV. PET data (maximum ring difference (MRD) = 85) were reconstructed using various reconstruction parameters and reprocessed to obtain images at shorter scan durations. Maximum, mean and peak activity concentration recovery coefficients (RC) were obtained for each sphere and compared to EARL standards specifications.

Additionally, PET data (MRD = 85) of 10 oncological patients were acquired and reconstructed using various reconstruction settings and reprocessed from 10 min listmode acquisition into shorter scan durations. Per dataset, SUVs were derived from tumour lesions and healthy tissues. ANOVA repeated measures were performed to explore differences in lesion SUV_max and SUV_peak. Wilcoxon signed-rank tests were performed to evaluate differences in background SUV_peak and SUV_mean between scan durations. The coefficient of variation (COV) was calculated to characterise noise.

Results

Phantom measurements showed EARL compliance for all positions throughout the LAFOV for all scan durations. Regarding patient data, EARL-compliant images showed no clinically meaningful significant differences in lesion SUV_max and SUV_peak or background SUV_mean and SUV_peak between scan durations. Here, COV only varied slightly.

Conclusion

Images obtained using the Vision Quadra PET/CT comply with EARL specifications. Scan duration and/or activity administration can be reduced up to a factor tenfold without the interference of increased noise.

中文翻译：

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使用体模和临床数据对 Biograph Vision Quadra PET/CT 进行 EARL 依从性和成像优化

目的

当前欧洲核医学协会 (EANM) 研究有限公司 (EARL) 为传统系统开发的 PET 成像标准化指南尚未针对长轴视场 (LAFOV) 系统进行调整。为了在多中心研究和协调临床使用中使用 LAFOV Siemens Biograph Vision Quadra PET/CT（Siemens Healthineers，Knoxville，TN，USA），符合^{18的 EARL 规范}在当前的研究中探索了 F-FDG 肿瘤成像。包括在整个 LAFOV 的不同位置进行的额外测试和使用更短的扫描持续时间。此外，还收集了临床数据，以进一步探索和验证在使用符合 EARL 的重建设置时减少扫描持续时间对半定量 PET 图像生物标志物准确性和精确度的影响。

方法

使用 NEMA 图像质量模型在整个 LAFOV 的中心和不同位置执行 EARL 合规性模型测量。使用各种重建参数重建 PET 数据（最大环差 (MRD) = 85）并重新处理以在更短的扫描持续时间内获得图像。获得每个球体的最大、平均和峰值活性浓度恢复系数 (RC)，并与 EARL 标准规范进行比较。

此外，使用各种重建设置获取和重建 10 名肿瘤患者的 PET 数据（MRD = 85），并将 10 分钟列表模式采集重新处理为更短的扫描持续时间。根据数据集，SUV 来源于肿瘤病变和健康组织。进行 ANOVA 重复测量以探索病变 SUV _max和 SUV _peak的差异。执行 Wilcoxon 符号秩检验以评估扫描持续时间之间背景 SUV_峰值和 SUV_{平均值的差异。}计算变异系数 (COV) 以表征噪声。

结果

体模测量显示在所有扫描持续时间内整个 LAFOV 的所有位置都符合 EARL 标准。关于患者数据，符合 EARL 标准的图像显示扫描持续时间之间的病变 SUV_最大值和 SUV_峰值或背景 SUV_平均值和 SUV_峰值没有临床意义的显着差异。此处，COV 仅略有变化。

结论

使用 Vision Quadra PET/CT 获得的图像符合 EARL 规范。扫描持续时间和/或活动管理可以减少多达十倍，而不会增加噪音的干扰。