| Worldwide, the coronary heart diseases has become not only the common cause of impairing human health , but also the commonest cause of death .Coronary arteriography (CAG) is the "gold standard "of diagnosising the coronary heart diseases by two-dimensional angiography to detect stenotic coronary artery stenotic invasively ,but limited to evaluate the myocardial perfusion supplied by a stenotic coronary artery .Along with the development of MR equipments, the MR myocardial perfusion imaging has become an advanced technique for noninvasive detection of coronary heart diseases .MR myocardial perfusion imaging not only is used to detection of coronary heart diseases but also used in re-perfusion, evaluating the effect of coronal pass-b or dilataltion 。Compared with the other noninvasive SPECT, PET, etc ,the MR myocardial perfusion imaging has the better tissue and time resolution ,can also acquisite images by multiplane and multidimensional tomoraphic scanning. This technique can provide the real-time information about myocardial perfusion, and reflect the effect of stenotic coronary artery to myocardial perfusion directly and accurately By going through the domestic and international cultural related in 20 years, only a little cultural reported this and big part of this was concentrated in foundation research and clinical qualitative analysis. What is new in our study is comparing myocardial perfusion imaging before and after stress with CAG .Only a few researchers took notice of the signal intensity in first-pass phase,and only a few experiments was on measuring the dgree of the myocardium signal increase the myocardium supplied by a stenotic coronary artery or supplied by a non stenotic coronary artery . 20 healthy volunteers and 30 patients who were diagnosed CHD according to ISFC/WHO and confirmed by DSA were performed MR myocardial perfusion imaging before and after ATP stress with GE Singa CV/i 1.5-T imager and the cardiac phased-array coil for adults under ECG and breath gating . Scanning sequences as follows:1, the real fast and steady returns ( FIESTA) were used for cardiac long-axis and short-axis cine MRI. 2 fast gradient-echo pulse were used for myocardial perfusion imaging .The experiment includes:1, myocardial perfusion scanning at rest: myocardial perfusion imaging before ATP stress 2, myocardial perfusion scanning under stress :one hour after step 1,through elbow vein ATP were injected for 5 minutes; 3 minutes after starting injection repeat the step 1.ATP dosage was 0.1kg-1.Min-1 and injection time was 5 minutes; 15ml gadolinium DTPA(Magnevist) was rapidly injected with 3-5ml/s。All images were send to the independent work station (SUN WORK STATION) automatically, then the images were observed and the data were measuresed and analyzed. 1 Observe images characteristics before and after stress and analyze the difference between images signal.2 .gain ROIs signal intensity-time curves applying GE AW4.0 work station DCEMI( Dynamic Contrast Enhanced Myocardial Imaging) software bag,ROIs include myocardial segments supplied by stenotic coronary artery conformed by CAG。low signal segments and normal myocardial segments .the intensity-time curves were analyzed. the ratio of upslopes before and after stress were achieved respectively,the results were mean +/-SD, SPSS11.0 analysis software was used to analyze the difference between two data .Finally, compare the relativity between MR myocardial perfusion imaging and coronary artery angiography in diagnosing CHD. Result:1. there was no low signal regions in 20 healthy volunteers before and after ATP stress and low signal regions were found in some of 30 patients, moreover the obvious low signal regions were found after st ress 2.from signal intensity strength-time curves, we can get the the reference... |
