PET/CT显像中呼吸运动对肺结节SUV的影响及其校正

摘要

Objective: This study was designed to investigate the impact of breathing on evaluation of positive lung nodules and establish a correction method for positron emission tomography/computed tomography (PET/CT). Methods: Model studies are adopted to simulate breathing. Its influence on the standardized uptake value (SUV) of positive nodules on PET/CT images were analyzed by correlating with the images obtained in static status. A mathematic correction method was established and veriifed through case analysis. Results:Compared with the PET images under static status, the average SUVs under breathing status decreased, whereas the nodule volume (V) increased correspondingly and the total radioactivity (TR=SUVmean×V) remained the same. Because the volume measured on the high-speed multi-detector CT was relatively accurate, the decreased SUVs on clinical PET images with breathing inlfuence could be corrected using a formula: SUVcor ected= (SUVmeasured × VPET) /VCT. Conclusion:A mathematic method is preliminarily established to correct the breathing-related underestimation of the SUVs of positive lung nodules on PET/CT images.%目的：研究正电子发射断层/计算机断层（PET/CT）显像中呼吸运动对肺阳性病灶标准摄取值（SUV）的影响及校正方法。方法：用模型模拟呼吸运动进行PET/CT显像，研究呼吸运动对阳性球状灶SUV的影响，提出数学校正方法，并通过临床病例分析进行验证。结果：与静止时PET图像比较，呼吸运动时采集的阳性球状灶SUV降低，但体积（VPET）相应增大，而其内的总放射性（TR=SUV平均×V）保持不变。临床上，PET所示病灶为呼吸运动叠加的结果，而高速多排螺旋CT所示的病灶体积（VCT）与真实体积比较接近，因此建立了通过公式SUV校正=(SUV测量×VPET)/VCT进行校正的方法。结论：PET/CT显像中肺结节的SUV因呼吸运动而被低估，可通过所建简便方法进行校正。