Study Of Imaging Technology And Clinical Application On Free Breathing Whole Heart Coronary MRA With Real Time Navigator At 3.0T MRI

Objective To investigate the imaging technology of free breathing whole heart coronary magnetic resonance angiography (CMRA) with real time navigator at 3. 0 T MRI and find the factors that effect the image quality and evaluate the applicative value of CMRA on the diagnosis of coronary artery disease.Materials and method 17 cases of healthy volunteers and 26 cases suspected of having coronary heart disease (CHD) were examined with free breathing whole heart coronary MRA by real time navigator at 3. 0 T MRI. Examination was taken in 26 cases suspected of having coronary heart disease in one week before operation of selected coronary angiography. CMRA was obtained at Philips Achieva 3. 0T Medical Systems by using a turbo field echo sequence. High resolution three dimensional (3D) coronary MR images covering the coronary arterial system were acquired with a navigator gated for respiratory artifact suppression. 3D reconstruction of whole heart CMRA was performed by "Soap Bubble" curved planar reconstruction. To evaluate the feasibility of whole-heart CMRA to show the coronary arteries and find the factor that effect the image quality and evaluate the applicative value of CMRA on the diagnosis of coronary artery disease at 3. 0 T MRI. Result Whole heart CMRA were successfully completed in 39 of 43 cases (90.7 %); 112 normal branches and 208 segments were shown in 28 normal cases (15 cases of healthy volunteers and 26 cases suspected of having coronary heart disease) by 3. 0T CMRA. There were 21 cases whose heart rate <70/min, 7 cases whose HR were between 70/min and 84/min. The statistical different in the visible coronary segments of right coronary artery was significant (p=0. 0007). There was no statistical significant difference in the visible coronary segments of left anterior descending coronary (LAD) and left circumflex coronary (LCX) .All left major coronary artery were shown in the 28 cases(100%). When HR <70/min , the main vessels of coronary artery, including their distal segments and smaller diameter branching vessels can be displayed. There were statistical significant difference in the coronary image quality in different heart rate groups (H=12.1849,P=0.0003),the image quality was excellent when the heart rate no more than 70 times per minute. The way prolong the course of expiration base on uniformity breathing can increased the san efficiency. CMRA displayed 24 significance stenosis (more than 50%)of 22 branches in 11 cases. Comparing with the results of SCA, the agreement rate, sensitivity , specificity , false positive rate , false negative rate , likelihood ratio , positive and negative predictive values of whole heart 3T CMRA for detecting significant stenosis were 93. 1%, 84 % , 96. 1 % , 16%, 3. 9%, 21. 5, 87. 5 % and 94. 9 % , respectively. Conclusion the main vessels of coronary artery , including their distal segments and smaller-diameter branching vessels can be displayed by 3.0T CMRA. It can meet the clinic require . High resolution free breathing whole heart coronary MR angiography with a navigator gated can allows for the accurate detection of coronary artery disease noninvasively and reveal syndrome of CHD. 3. 0T CMRA can be used as a sereening tool in suspected cases of CHD before the operation of SCA .