两种图像重建算法对实验肿瘤模型的^(18)F-脱氧葡萄糖PET/CT定量结果的影响

Effect of two image reconstruction algorithms on the quantification analysis of experimental animal tumor model with ^(18)F-FDG PET/CT

目的:比较不同图像重建算法对试验动物肿瘤的18F-脱氧葡萄糖(FDG)PET定量分析的影响。方法:选用5只新西兰大白兔,于前肢种植VX2瘤,分别进行18F-FDG PET动态显像,获得肿瘤的动态图像,利用滤波反投影法(filtered backprojection method,FBP)及有序子集最大期望值法(ordered-subset expectation maximization algorithm,OSEM)进行图像重建,计算并比较肿瘤的Ki值和SUVmax。结果:FBP法重建图像的噪声较OSEM法高,两种算法重建的图像定量计算的参数Ki与SUVmax均高度相关(r≥0.95),但是OSEM法重建图像计算的Ki和SUVmax(Ki:0.03±0.013;SUV:4.89±1.69)明显高于FBP法重建图像的计算值(Ki:0.025±0.011;SUV:4.14±1.42),P均<0.05。结论:不同重建算法对18F-FDG PET定量分析的结果不同。在相同条件下,OSEM重建图像计算的定量参数明显高于采用FBP重建算法计算的定量参数。

Objective: To compare the effect of image reconstruction algorithms on the quantification analysis of experimental animal tumor model with18F-FDG PET / CT. Methods: Dynamic scans with18F-FDG PET / CT were performed in five New Zealand rabbits bearing VX2 tumor in fore limbs,tumor dynamic images were obtained and reconstructed with both filtered back projection method( FBP) and ordered-subset expectation maximization algorithm( OSEM). Quantification parameters of Ki and SUVmax were calculated and compared. Results: More noise presented in the images reconstructed by FBP than that by OSEM. Ki and SUVmax calculated by both reconstruction algorithms correlated well( r≥0. 95); Ki and SUVmax calculated from images reconstructed by OSEM( Ki: 0. 03 ± 0. 013; SUVmax: 4. 89 ± 1. 69) were significantly higher than that by FBP( Ki: 0. 025 ± 0. 011; SUVmax: 4. 14 ± 1. 42),all P < 0. 05. Conclusion: Reconstruction algorithms had effect on the quantification measures,and parameters calculated from image reconstructed by OSEM was higher than that by FBP.