PET/CT显像中连续采集模式病灶定量参数分析比较研究

Quantification in whole-body positron emission tomography(PET)with continuous bed motion(CBM)

目的:以步进采集(SS)模式作为“金标准”,与连续采集(CBM)模式进行配对比较,评估良性及恶性病变在CBM采集方式下多种定量指标的可靠性。方法:选取24例接受PET/CT检查者,随机先后采用CBM和SS模式在Siemens Biograph Vision 600 PET/CT完成图像采集。采用40%SUV阈值勾画容积感兴趣区,记录病灶标准摄取值(SUVmax、SUVpeak、SUVmean)、总糖酵解值(TLG)、代谢肿瘤体积(MTV)值。采用配对t检验及Pearson相关分析评价2组数据间的差异。结果:24例患者均经病理确诊,7例良性,17例恶性,共13个良性病灶和49个恶性病灶用于定量分析。除良性病变MTV因标准误差为0,无法计算相关性和t值,不论是良性病变还是恶性病变,在SS模式和CBM模式采集条件下SUVmax、SUVpeak、SUVmean、TLG、MTV值差异均无统计学意义(t=-0.726~0.973,P>0.05)。各定量参数在良性(r>0.995)及恶性病变(r>0.985)中存在较好相关性。Bland-Altman分析显示2种采集模式下良性及恶性病变平均差异值均接近0。结论:在良性及恶性病变中,CBM模式可提供可靠、准确的PET定量参数值,等同于SS采集获得的定量参数。

Objective:To evaluate the accuracy of multiple quantitative parameters of benign and malignant lesions on PET/CT with CBM acquisition mode,comparing it with step and shoot(SS)mode as the"golden standard".Methods:Twenty-four patients were examined in Siemens Biograph Vision 600 PET/CT using CBM and SS modes at random.The ROI(region of interest)was delineated using 40%SUV threshold,and the standard uptake value(SUVmax,SUVpeak,SUVmean),total glycolysis(TLG),and metabolic tumor volume(MTV)values of the lesions were recorded.Paired t test or paired rank sum test and Pearson correlation analysis were used to evaluate the difference between the two groups of data.Results:All patients were confirmed by pathology,7 cases were benign,17 cases were malignant.Altogether 13 benign lesions and 49 malignant lesions were measured for quantitative analysis.The standard error of MTV for benign lesions is 0,thus the correlation and t value cannot be calculated.No significant statistical difference(t=-0.726~0.973,P>0.05)was found in SUVmax,SUVpeak,SUVmean,TLG,MTV values obtained under SS mode and CBM mode acquisition conditions for both benign and malignant lesions.The quantitative parameters had good correlation in benign(r>0.995)and malignant lesions(r>0.985).Bland-Altman analysis showed the average difference between benign tumors or malignant lesions under the two modes was close to 0.Conclusion:In benign and malignant lesions,CBM mode can provide reliable and accurate quantitative parameters of PET,which is comparable to those obtained by SS.