PET/CT衰减系数转换方法对标准摄取值测量的影响研究

Effect of Different Attenuation Coefficient Transformation Algorithms on PET/CT SUV Measurement

目的研究两种不同的衰减系数转换方法对正电子发射计算机断层显像/计算机体层扫描(PET/CT)标准摄取值(SUV)测量值的影响。方法 2009年11-12月,从经过PET/CT氟代脱氧葡萄糖(FDG)显像患者中选取20例,其口腔中均有金属假牙。以四段转换法和二段转换法重建全身衰减校正断层图像。分别选取3种高密度区域和7种低密度区域,测量其最大SUV和平均SUV,比较两种转换方法SUV测量值。结果平均SUV:二段转换法的3种高密度区域SUV降低,在7种低密度区域中,1种区域增高,1种区域降低(P值均<0.05)。最大SUV:二段转换法的2种高密度区域的SUV降低,在7种低密度区域中,1种区域增高,2种靠近高密度组织的区域降低(P值均<0.05)。结论二段转换法能降低高密度区域的SUV,可用于减小体内金属植入物和CT对比剂造成的过度校正。

Objective To explore the effect of two attenuation correction algorithms on PET/CT SUV measurement.Methods From November to December 2009,the PET Slice of 20patients with metallic dental implant were reconstructed with four-and two-section algorithms respectively.Mean SUV and maximum SUV were measured in three high-density areas and 7low-density areas.Paired t test were performed to compare the differences.Results Mean SUV：two-section algorithm produced significantly lower SUV in all the three high-density areas;in the 7low-density areas,SUV increased obviously in one area and decreased apparently in one area（P0.05）.Maximum SUV： two-section algorithm produced significantly lower SUV in two high-density areas,SUV increased obviously in one area and decreased apparently in two areas which was adjacent to the high density areas（P0.05）.Conclusion Two-section algorithm produces lower SUV measurement value than the four-section algorithm does,and it is useful in PET/CT studies for patients with metallic dental implant and when CT contrast is used.