摘要
目的 评估99m锝 亚甲基二膦酸盐 (Tc99m MDP)三相骨显像对糖尿病足 (DF)的诊断价值。 方法 对 4 5例DF患者和 36例对照者进行Tc99m MDP三相骨显像。每个单足单独进行资料处理。在足背 (楔骨和跖骨 )、胫骨粗隆各勾画感兴趣区 (ROI) ,计算各ROI放射性浓度 (千计数 /像素 ,counts/ pixel)以及足部 /胫骨放射性浓度比值 (Rm/t)。生成各ROI的时间 活度曲线 ,从曲线读取各部位的灌注时间 (Tp) ,并计算各部位摄取速率 (V)。患足与健足之间Rm/t、Tp、V等指标的比较采用t检验。计算各指标的诊断灵敏度、特异性、准确率。各指标对DF诊断效能的差异采用u检验。 结果 Tp、V、Rm/t比值在对照组分别为 (33± 9)s、(2 3± 0 8)counts/s、0 85± 0 2 9,在DF组分别为(36± 13)s、(1 5± 0 3)counts/s、0 72± 0 31。两组之间比较 ,除Tp差异无显著意义外 (t=1 80 2 4 ,P>0 0 5 ) ,V(t=7 736 0 ,P <0 0 0 1)及Rm/t比值 (t=2 7395 ,P <0 0 1)在两组间差异均有显著意义。V值诊断DF的灵敏度为 82 6 % ,特异性为 83 8% ,准确率为 83 3% ,Rm/t比值则分别为 6 5 2 %、6 8 8%、6 7 3%。V值的灵敏度 (u =2 32 74 ,P <0 0 5 )和特异性 (u =2 4 0 6 8,P <0 0 5 )均优于Rm/t比值。
Objective To evaluate the diagnostic efficacy o f Tc 99m -MDP bone scintigraphy in diabetic foot. Methods Tc 99m -MDP three-phase bone imaging was performed on 45 cases with di abetic foot and 36 controls without diabetes mellitus.Each foot was analyzed in dependently. Radioactive concentration per pixel(C,counts/pixel) was calculate d and the time-radioactivity curve of each region of interest (ROI) was created .The ratio of foot to tibia(R m/t ) was calculated.From the curve of perfu sion time (Tp) was read out and the uptake velocity(V)of foot was calculated. The indices such as R m/t ,Tp and V were compared between two groups.The di agnostic indices such as sensitivity,specificity,accuracy,positive prediction va lue and negative prediction value were calculated and compared. Result s In control group,the Tp,V and R m/t were (33±9)s, (2.3±0.8)c ounts/s and 0.85±0.29,respectively; in diabetic foot group, the Tp,V and R m/t were (36±13)s, (1.5±0.3)counts/s and 0.72±0.31,respectively.Tp s howed no significant difference (P>0.05), but V (P<0.001)and R m/t (P<0.01) showed significant difference when compared between the two gro ups. The sensitivity,specificity, and accuracy were 82.6%,83.8% and 83.3%,r espectively for the V value, and 65.2%, 68.8% and 67.3%,respectively for th e ratio of R m/t . The sensitivity(P<0.05) and specificity(P<0.05 ) of V value surpassed those of R m/t . Conclusions Tc 99m -MDP three-phase bone imaging can find the decreased uptake velocity (V)and foot-tibia ratio in diabetic foot.The uptake velocity is more sensiti ve and special than the foot-tibia ratio in the diagnosis.
