CT衰减校正在IQ-单光子发射型电子计算机断层扫描心肌灌注显像中的应用价值

摘要

Objective:Using percent of radioactive counts (PRC) and auto-scores of 17 segments to evaluate the impact of CT attenuation correction (AC) on IQ-SPECT myocardial perfusion imaging (MPI) in patients without coronary artery disease.Methods:Fifty-nine patients [male 28,female 31,age (8.3 ± 9.8)years,body mass index (24.9 ± 3.4) kg/m2],who had negative rest + stress MPI result,and coronary angiography or coronary CT angiography showed that the coronary artery was normal or with the stenosis ＜ 50％,were respectively enrolled,and rest image of MPI was analyzed.Before and after AC,myocardial uptake (％)and scores were analyzed by using 4DM software,17 segments and 5-score system.Two-sample t test was used for the comparison between patients with AC and NOAC.Independent-samples T test was used for the comparison between male and female.Results:Mter AC,myocardial uptake (％) in inferior wall and septal wall was remarkably increased,while myocardial uptake (％) in apex was decreased significantly (P ＜ 0.05).After AC,myocardial uptake (％) was increased in 86％ (51/59) inferior wall and 85％ (50/59) septal wall while it was decreased in 100％ (59/59) apex.However,scores in most inferior wall (78％,46/59),septal wall (59％,35/59) and apex (69％,41/59) were not significantly changed.It indicated score was reliable.Meanwhile,after AC,in female patients,myocardial uptake was decreased in apex and anterior wall,which might lead to false positive MPI result.Conclusion:After AC,myocardial uptake was significant increased in inferior wall and septal wall,while it was significantly decreased in apex.%目的:以无冠心病者为研究对象,IQ-SPECT模式采集图像,采用4DM软件对心肌节段的放射性摄取值(％)和17节段自动评分系统对结果进行评价,比较CT衰减校正(AC)对心肌灌注显像(MPI)结果判断的影响.方法:对59例行静息+负荷SPECT MPI结果为阴性,且冠状动脉造影或冠状动脉CT造影检查结果提示冠状动脉未见狭窄或狭窄＜50％,对其静息心肌灌注图像进行回顾性分析.其中男性28例,女性31例,年龄(58.3±9.8)岁,体质指数(24.9±3.4)/(kg/m2).采用4DM软件比较衰减校正前后左心室5个大的心肌节段(心尖、前壁、间隔、下壁和侧壁)的放射性摄取值(％),以及17个心肌节段评分的变化情况.结果:AC后受检者下壁和间隔的放射性摄取值(％)显著性升高,心尖部的放射性摄取值(％)则明显降低(P＜0.05).AC后86％(51/59)的下壁和85％ (50/59)间隔的放射性摄取值(％)升高,100％ (59/59)心尖部放射性摄取值(％)均降低.采用17节段5分法的评分系统,AC后多数下壁(78％,46/59)、间隔(59％,35/59)和心尖部(69％,41/59)的评分保持不变.但对女性患者,AC后42％(13/31)的前壁和心尖部评分值均增加,可能会导致假阳性结果.结论:IQ-SPECT模式下,AC会导致受检者下壁和间隔的放射性摄取值(％)明显升高,心尖部则显著降低.临床医师在图像判读时需引起注意.