基于体积测量的^(18)F-FDG PET/MR与PET/CT代谢参数的比较

Comparison of metabolic parameters between ^(18)F-FDG PET/MR and PET/CT based on volume measurement

目的:比较^(18)F-FDG PET/MR与PET/CT在基于体积测量的代谢参数的相关性和差异性。方法 :回顾性分析37例经病理或影像学随访证实为肝转移瘤的患者,所有患者同日先后接受PET/CT及PET/MR显像。根据2种检查的先后顺序分为先PET/CT后PET/MR组24例和先PET/MR后PET/CT组13例。分别在PET/MR及PET/CT图像中测量病灶的标准化摄取值(SUV)峰值(SUV_(peak))、SUV平均值(SUV_(mean))、肿瘤代谢体积(MTV)及糖酵解总量(TLG)。采用Spearman秩相关分析、Wilcoxon秩和检验比较2种检查方法在病灶各代谢参数值间的相关性和差异性。结果:先PET/CT后PET/MR组共测量46个病灶,先PET/MR后PET/CT组共测量24个病灶。PET/MR与PET/CT在病灶SUV_(peak)、SUV_(mean)、MTV、TLG均具有较好的相关性(r=0.726~0.973,均P<0.001)。PET/MR中病灶的SUV_(peak)、SUV_(mean)、TLG均高于PET/CT。在先PET/CT后PET/MR组中,病灶PET/CT MTV显著高于PET/MR MTV(Z=-2.156,P<0.05),在先PET/MR后PET/CT组中,病灶PET/MR MTV高于PET/CT MTV(Z=-2.800,P<0.05)。结论:^(18)F-FDG PET/MR与PET/CT在基于体积测量的代谢参数均具有较好的相关性,提示PET/MR基于体积的半定量分析具有较好的稳定性和可靠性。MTV受检查顺序的影响超过机器类型,当PET/MR与PET/CT交替使用时,MTV可能是一个相对比较合适的指标。

Objective: To assess the correlation and difference of metabolic parameters between ^(18)F-FDG PET/MR and PET/CT based on volume measurement. Methods: Thirty-seven patients with liver metastases confirmed by pathology or imaging were retrospectively analyzed. All patients underwent PET/CT and PET/MR on the same day. Patients were divided into two groups, PET/CT first and sequentially PET/MR group(n=24) and PET/MR first and sequentially PET/CT group(n=13).Peak and mean standardized uptake values(SUV_(peak)and SUV_(mean)), metabolic tumor volume(MTV) and total lesion glycolysis(TLG)were measured in PET/MR and PET/CT. Spearman’s rank correlation analysis and Wilcoxon’s signed rank test were performed to assess the correlation and difference of metabolic parameters between the two group. Results: Forty-six lesions were measured in PET/CT first and sequentially PET/MR group, and twenty-four lesions were measured in PET/MR first and sequentially PET/CT group. There were significant correlations of SUV_(peak), SUV_(mean), MTV, and TLG between PET/MR and PET/CT(r=0.726~0.973, all P<0.001). The SUV_(peak), SUV_(mean), and TLG of lesions in PET/MR were higher than that in PET/CT. In PET/CT first and sequentially PET/MR group, the PET/CT MTV of lesions was significantly higher than PET/MR MTV(Z =-2.156, P<0.05). In PET/MR first and sequentially PET/CT group, the PET/MR MTV of lesions was significantly higher than PET/CT MTV(Z=-2.800, P<0.05). Conclusion: There are significant correlations of metabolic parameters between^(18)F-FDG PET/MR and PET/CT based on volume measurement, suggesting that PET/MR has good stability and reliablity in metabolic parameters based on volume measurement. MTV is affected by exam order more than machine type, suggesting that MTV is relatively more appropriate index than others when PET/MR and PET/CT are used interchangeably.