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目的 在健康及急性心肌梗死小型猪模型中验证99Tcm-3SPboroxime(3SP)作为快速心肌灌注显像(MPI)药物的优势.方法 制备99Tcm-Teboroxime (TEBO)和99Tcm-3SP.取2只健康小型猪,麻醉后经静脉分别注射370 MBq 99Tcm-TEBO或99Tcm-3SP,立即用标准SPECT动态采集平面图像,持续采集20 min,测量心脏、肝和肺的放射性计数及心/肝、心/肺比值,并观察其随时间的变化;取4只健康小型猪和1只急性心肌梗死模型猪,麻醉后经静脉分别注射370 MBq 99Tcm-TEBO和99Tcm-3SP,同1只猪体内2种显像剂的注射分别在连续2d内完成,同时用碲锌镉心脏专用SPECT仪(CZT-SPECT)动态采集断层图像15 min,测量心肌、肝的放射性计数及心/肝比值,评价MPI图像质量.采用配对t检验分析数据.结果 99Tcm-TEBO和99Tcm-3SP的放化纯均＞95％.99Tcm-3SP的初始心肌摄取与99Tcm-TEBO接近[平面显像,注射后2 min:309.32× 103与314.13×103计数/MBq;断层显像,注射后2 min(已校正):7.96±0.87与8.24± 1.53,t =0.277,P＞0.05],但心肌滞留优于99Tcm-TEBO[平面显像,注射后20 min:218.67× 103与143.19× 103计数/MBq;断层显像,注射后15 min(已校正):6.76±0.45与5.06±0.33,t=-12.412,P=0.001].两者肝摄取及心/肝比值相似(注射后15 min内,t值:-1.332～1.101,均P＞0.05).CZT-SPECT MPI显示,正常心肌对99Tcm-3SP呈分布均匀的高摄取,梗死心肌呈放射性缺损改变.在99Tcm-3SP注射后15 min内的任意5 min显像时间窗中,正常与心肌梗死小型猪均可获取高质量的SPECT图像.结论 99Tcm-3SP心肌摄取较高,注射后20 min内均有明显的心肌滞留,SPECT图像质量优越,是一种生物学性能优异的99Tcm标记快速MPI药物.“,”Objective To assess the superiority of 99Tcm-3SPboroxime (99Tcm-3SP for short) as a fast-myocardial perfusion imaging (MPI) tracer in normal and acute myocardial infarction (AMI) mini-swine.Methods 99Tcm-3SP and 99Tcm-Teboroxime (99Tcm-TEBO for short) were prepared.Approximately 370 MBq 99Tcm-3SP or 99Tcm-TEBO was injected intravenously in 2 healthy mini-swine separately.Dynamic planar images were acquired immediately after injection and continued for 20 min using a standard SPECT camera.The radioactivity uptakes in the heart,liver,and lungs were measured,and heart/liver and heart/lung ratios over time were calculated.Dynamic SPECT studies were performed in 4 normal swine and 1 AMI-swine using cadmium zinc telluride-SPECT (CZT-SPECT).List mode acquisitions were immediately started and continued for 15 min after intravenous injection of approximately 370 MBq 99Tcm-TEBO and 99Tcm-3SP.The injection of two radiotracers in the same swine was completed within 2 d.The radioactivity uptakes in heart and liver were measured,and heart/liver ratio was calculated.Image quality was also evaluated.Paired t test was used to analyze the data.Results The radiochemical purity of 99Tcm-TEBO or 99Tcm-3SP were both above 95％.The initial heart uptake of 99Tcm-3SP was very close to that of 99Tcm-TEBO (planar image,2 min postinjection:309.32× 103 vs 314.13 × 103 counts/MBq;SPECT image,2 min postinjection (corrected):7.96±0.87 vs 8.24± 1.53,t =0.277,P＞0.05),but the myocardial retention time was much longer than that of 99Tcm-TEBO (planar image,20 min postinjection:218.67× 103 vs 143.19× 103 counts/MBq;SPECT image,15 min postinjection (corrected):6.76±0.45 vs 5.06±0.33,t =-12.412,P =0.001).The uptake of liver and heart/liver ratio between 99Tcm-TEBO and 99Tcm-3SP were similar (t values:-1.332-1.101,all P＞0.05 within 15 min).SPECT MPI images demonstrated uniform tracer distribution with clearly visualizable myocardial boundary in normal myocardium and intense perfusion defect in infarct myocardium.High quality SPECT images could be obtained in any of the 5 min imaging windows over the first 15 min after injection of 99Tcm-3SP in normal swine and AMI-swine.Conclusion 99Tcm-3SP is a promising 99 Tcm-labeled radiotracer for fast-MPI considering its high heart uptake,long myocardial retention time (20 min postinjection) and superior SPECT image quality.