肺部病变18F-FDG符合线路显像不同参照点半定量值的对比研究

Comparative study of semi-quantitative value based on different reference point in diagnosis of pulmonary lesions with 18F-FDG coincidence imaging

目的 探讨18 F-FDG符合线路显像诊断肺部病变良恶性的最佳半定量阈值.方法 对137例肺部病变患者(男89例,女48例,年龄33 ～ 78岁)行18F-FDG符合线路显像,测量肺部病变(T)、正常胸壁软组织(NT1)及对侧相应肺组织(NT2)的最大放射性.以正常胸壁软组织和对侧相对应肺组织为参照点,分别计算肺部病变半定量摄取比值R1(T/NT1)及R2(T/NT2),应用ROC曲线确定肺部病变良恶性的最佳临界值R1(cutoff)、R2(cutoff),并计算其对应的灵敏度、特异性、准确性.结果 R1(cutoff)取3.58,R2(cutoff)取4.40;按此2个最佳临界值,18F-FDG符合线路显像诊断肺部病变的灵敏度、特异性、准确性分别为90.0％ (90/100)、89.2％ (33/37)、89.8％ (123/137)和90.0％ (90/100)、78.4％(29/37)、86.9％ (119/137).结论 以胸壁软组织为参照点,半定量摄取比值取3.58作为18F-FDG符合线路显像诊断肺部病变良恶性的阈值更可靠.

Objective To explore the optimal semi-quantitative uptake ratio for differentiation between benign and malignant lung lesions with 18F-FDG coincidence imaging.Methods One hundred and thirty-seven patients (89 males,48 females,age range:33-78 years) with lung diseases underwent 18 FFDG coincidence imaging.The maximum radioactivity counts of the lung lesions (T),normal chest wall soft tissues (NT1) and the contralateral lung tissue (NT2) were measured.The ratios of R1 (T/NT1) and R2(T/NT2) were calculated.The optimal threshold values of R1(cutoff)and R2(cutoff) were identified by ROC curve analysis.Using the optimal threshold,the sensitivity,specificity and accuracy were calculated.Results The optimal threshold values R1(cutoff)and R2(cutoff) were identified as 3.58 and 4.40.The sensitivity,specificity and accuracy were 90.0％(90/100),89.2％(33/37),89.8％(123/137) according to R1(cutoff) and 90.0％ (90/100),78.4％(29/37),86.9％(119/137) according to R2(cutoff) Conclusion Based on which the chest wall soft tissue is taken as a reference point,the optimal threshold value of T/NT1 is 3.58 in differentiation between benign and malignant lung lesions with 18F-FDG coincidence imaging.