猪心梗模型MR首过灌注及延迟成像的技术探讨

目的：探讨MR首过灌注剂量及延迟扫描最佳成像时间，以获得较好心肌灌注图像及最佳延迟增强图像。方法：采用1.5T磁共振扫描仪行不同剂量（0.05mmol/kg组与0.1mmol/kg组）的首过灌注及不同延迟增强时间扫描，并对结果行统计学分析。结果：首过灌注剂量0.05mmol/kg组与0.1mmol/kg组，两组显示的心肌灌注降低或缺损区节段数有统计学差别（P<0.05）。不同延迟增强扫描时间数据显示：①在10min与5min时、40min与30min时的信号值有统计学意义；②5～10min是心肌缺损区信号值不断上升的一个阶段，10～30min信号值相对较平稳，30～40min心肌缺损区的信号值较前呈明显下降趋势。结论：首过灌注剂量0.1mmol/kg较0.05mmol/kg更利于检出缺血心肌；延迟增强扫描时间以10～30min之间的图像质量为最佳；有助于MRI更好的应用及心肌活性评价。

The technology of first-pass perfusion MR imaging and delayed enhanced MR imaging in the swine myocardial infarction model: a preliminary study

Objective：To investigate the dose of first-pass perfusion and the best delayed scanning time.Thereby,the purpose is to get a better cardiac perfusion MRI images and the best delay-enhanced images.Method：Five experimental pigs with myocardial infarction underwent two MR myocardial first-pass perfusion imaging,the contrast agent dose were 0.05mmol/kg and 0.1mmol/kg respectively.Ten experimental pigs with myocardial infarction underwent delayed enhanced MR imaging at 5min,10min,30min,40min time point.The results were analyzed statistically.Result：There was statistical difference（P0.05） between the two groups（0.05mmol/kg and 0.1mmol/kg） in detection of the myocardial perfusion decrease or defect on the firstpass MR perfusion imaging.The data of the delayed enhancement MR imaging in different scanning time showed.①The signal values were statistically significant between 10 minutes and 5 minutes,40 minutes and 30 minutes;②The signal values of myocardial infarction showed rise in the stage of 5-10 minutes;and the signal values were relatively stable in the 10-30 minutes;During the stage of 30-40 minutes,the signal value of myocardial infarction showed a clear downward trend compared with the previous time.Conclusion：The perfusion imaging quality of the dose of the 0.1mmol/kg group is better than the 0.05mmol/kg group.It can detect more myocardial perfusion defects.Delayed time between 10-30min is the best scanning time to the delayed enhancement MR imaging.These are helpful in the assessment of myocardial viability using MR first-pass myocardial perfusion imaging and delayed enhancement MR imaging.