SPECT心肌灌注显像评价介入栓塞法猪急性心肌梗死模型

目的 应用SPECT心肌灌注显像（MPI）对介入栓塞法猪急性心肌梗死（AMI）模型进行评价,总结获得最佳图像质量的显像条件,为相关实验研究提供借鉴.方法 采用经冠状动脉丝线堵塞法制作小型猪AMI模型18头,于模型制作后1周行MPI.观察显像剂不同剂量、注射后不同显像间隔时间、采集方式及每帧采集时间对图像质量的影响；同时应用ECToolBox软件进行图像半定量分析.结果 （1）注射低剂量显像剂,采用注射至采集间隔30 min＋门控采集30 s/帧与间隔时间≥60 min＋门控采集25 s或30 s/帧图像无统计学差别；（2）注射高剂量显像剂,注射至采集间隔时间5～10 min＋门控采集25 s/帧,与低剂量组间隔≥30 min＋门控采集30s/帧图像无统计学差别.（3）应用半定量分析软件ECToolBox能够同时获得心肌梗死面积、舒张末期容积（EDV）、收缩末期容积（ESV）、左心室射血分数（LVEF）等定量参数,且可重复性好.结论 SPECT MPI能够无创性、直观评价猪AMI模型成功与否,并同时能半定量分析多项参数,结果重复性好；应用适宜的显像条件和操作方法能够有效地提高图像质量.

Assessment of acute myocardial infarction models with intervention embolism method in pigs by SPECT myocardial perfusion imaging

Objective To assess acute myocardial infarction（AMI）models with the intervention embolism method in minipigs by SPECT myocardial perfusion imaging （MPI）.Methods The middle-far segments of left descending coronary arteries in eighteen minipigs were obstructed with thread by percutaneous intervention method to prepare AMI models.SPECT MPI was performed one week after the procedure.Under the changes of the acquisition parameters,the results of influences on image qualities were analyzed by changing of the agent dose,the interval between the injection and the scan,the acquisition mode and the time for each projection.Then the data were semiquantitatively evaluated with ECToolBox software,acquiring a series of quantificational parameters.Results First,the image quality had no difference between the two acquisition modes after the injection when the imaging agent dose was relatively low.One was the 30 min interval before the adopted ECG gated mode（30 s per frame）,and the other one was over 60 min before the adopted ECG gated mode （25 s or 30 s per frame）.Second,the time interval only need 5-10 min when the dose was relatively high,then with the ECG gated acquisition mode（25 s per frame）.The image quality was good enough.There was no difference with the low dose injection,the time interval of more than 30 min and ECG gated acquisition mode（30 s per frame）.Third,it was proved to be highly reproducible using the semiquantitatively analysis software （ECToolBox）,and many quantificational parameters were simultaneously obtained,including the size of myocardial infarction,the weigh of infracted myocardium and the percentage,end diastolic volume（EDV）,end systolic volume （ESV） and the LVEF and so on.Conclusions SPECT MPI can be used for intuitively evaluating the success or failure of AMI models in pigs,and actualize quantitative analysis in the same time.The results for semi-quantitatively analysis are highly reproducible.Feasible scan condition and manipulation can effectively improve the image quality.