SPECT/CT双探头符合线路衰减与非衰减校正在肿瘤诊断中的应用

Lesion-to-background ratio in tumor 18F-FDG SPECT-CT with or without attenuation

目的 评价SPECT CT双探头符合线路衰减和非衰减校正技术对肿瘤诊断的意义。方法 用1 8F 脱氧葡萄糖 (FDG)SPECT双探头符合线路显像 ,经衰减和非衰减校正测量病灶的靶与本底 (L B)比值。结果 ①衰减校正检出恶性病变 4 1例 (5 6个病灶 )、良性病变 7例 (11个病灶 ) ;非衰减校正检出的良恶性病变部位和数量与衰减校正一致。②经衰减校正检出的 5 6个恶性病灶L B比值为 2 4 .0 7～ 1.39,平均 5 .2 0± 4 .2 8,其中 <2 .0为 8个 ,2 .0～ 2 .5为 7个 ,>2 .5为 4 1个 ;良性病灶 11个 ,L B比值为 2 0 .1～ 1.4 8,平均 5 .6 1± 4 .79,其中 <2 .0为 2个 ,2 .0～ 2 .5为 2个 ,>2 .5为 7个。③经衰减校正良恶性病灶L B比值平均为 5 .2 8± 3.5 1,非衰减校正为 3.2 2± 2 .0 0 ,两者间差异无显著性(P >0 .0 5 ) ,且呈正相关 (r =0 .77,P <0 .0 1)。结论 1 8F FDGSPECT双探头符合线路显像中衰减和非衰减校正对检出病灶数量和定位无明显区别 ,但前者图像明显好于后者。仅据L B比值判断良恶性病变不可靠。

ObjectiveTo compare the diagnostic efficacy of attenuation and non-attenuation in tumor 18F-FDG SPECT-CT. MethodsForty-eight cases underwent 18F-FDG SPECT-CT. Among them, 41 were with malignant tumors (56 lesions) and 7 were with benign space occupying lesions (11 lesions). Reconstructed attenuation-corrected and uncorrected images were displayed and the FDG uptake in lesions and corresponding background areas (L/B) were evaluated by the region of interest method. Results[WAlthough the numbers of lesions were not different between attenuated-corrected and uncorrected images, the attenuated images were clearer than uncorrected ones. The average ratio of L/B of attenuation group was 5.28±3.51, higher than the ratio of L/B of non-attenuation group, 3.22±2.00. There was a linear correlation between L/B ratios calculated on attenuated and non-attenuated images (r=0.77, P<0.01). ConclusionsAttenuation is worthwhile to use for the diagnosis of tumor. The ratio of L/B alone has its limitations to differentiate benignancy from malignancy.