无衰减校正对^(18)F-FDGPET全身肿瘤显像结果的影响

Effect of unattenuation correction on qualitative and semiquantitative lesion detectability in whole body FDG PET imaging

目的 探讨无衰减校正对18F 脱氧葡萄糖 (FDG)PET全身肿瘤显像定性和半定量分析结果的影响。方法 对 12例正常体检者和 5 2例肿瘤患者行18F FDGPET全身显像 ,分别用68Ge旋转棒源进行分割法衰减校正和无衰减校正图像重建。对PET图像进行定性和半定量分析。结果 经衰减校正图像的体内解剖结构比无衰减校正图像清晰 ,64例患者在经衰减校正图像上共检出 12 6个病灶 ,在无衰减校正图像上亦均检出。有无衰减校正显像的病灶与本底放射性计数比值 (L/B)差异无显著性 (t=1.89,P >0 .0 5 ) ,且两者明显相关 (r =0 .93)。结论 无衰减校正18F FDGPET肿瘤全身显像定性诊断价值与衰减校正显像近似 ,可计算L/B值 。

Objective To investigate the effect of unattenuation correction on qualitative and quantitative lesion detectability in whole body FDG PET imaging. Methods Whole body PET studies were performed in 12 normal subjects and 52 patients with various tumors 50 min after a bolus injection of 18 F FDG.Transmission and emission data were acquired. Reconstructed attenuation corrected and uncorrected images were analyzed qualitatively and semiquantitatively. Results Attenuation corrected and uncorrected images were found to be equally sensitive for detecting lesions. There was a strong linear correlation between lesion to background(L/B) calculated on attenuation corrected and uncorrected images( r=0.93,P <0.01),and no significant difference between them( t=1.89,P >0.05). Conclusions The efficacy of attenuation uncorrected images in qualitatively evaluating tumors is similar to that in attenuation corrected images. Uncorrected images could also provide semiquantitative information, but L/B ratio is the only available index. The anatomic location of tumors in attenuation corrected images was better than in uncorrected ones.