The Clinical Research Of 3.0 Tesla Contrast-enhanced Whole-heart Coronary MR Angiography

Part I The feasibility study of 3.0 tesla contrast-enhanced whole-heart coronary MR angiographyObjective To investigate the suitable imaging method of whole-heart coronary MR angiography (CMRA) on 3.0 tesla MR device.Materials and Methods 3.0T contrast-enhanced whole-heart magnetic resonance angiography(CE-CMRA) was utilizd to examine 12 volunteers using so-called navigator-gated, ECG-triggered, fat-saturated, segmented FLASH sequence for whole-heart coronary artery imaging during free breathing. The other 4 volunteers who had been examined by the same sequence without contrast agent administration.The image quality was estimated, and the principal branches of coronary arteries were evaluated based on AHA 9 segments classification.There were 40 source-images selected to measure and calculate the signal to noise ratio(SNR) and contrast to noise ratio(CNR) in each imaging model.Results 16 volunteers were examined successfully completed.CE-CMRA displayed 90% segments of coronary which image quality were good or excellent.However,none contrast enhanced CMRA showed poor image quality and the coronary segments were invisible.The SNR and CNR of source-iamges with CE-CMRA were higher than none contrast enhanced CMRA,and there was considered statistically significant between the two methods. Conclusions The navigator-gated, ECG-triggered, fat-saturated, segmented FLASH sequence for whole-heart coronary artery imaging during free breathing,combined with blood pool contrast agent injection,which can depict main artery segments,achieve better image quality, as well as higher SNR and CNR, is suitable for 3.0T whole-heart coronary MR angiography. PartⅡA control study between 3.0 tesla contrast-enhanced whole-heart coronary MR angiography and coronary computer tomography angiographyObjective To investigate the clinical value of 3.0 tesla contrast enhanced whole-heart coronary MR angiography (CE-CMRA) in coronary artery disease.Materials and Methods 3.0 T CE-CMRA was utilizd to examine 21 patients who had been examined by coronary computer tomography angiography(CCTA). Gd-BOPTA (0.2mmol/kg) was injected in vein with slow infusion rate(0.3ml/s) to perform enhancement. Datas was post-processed to obtain principal branches of coronary artery and picture's quality was evaluated. According to the results of CCTA, the principal branches were evaluated based on AHA 9 segments classification of coronary artery.Results 21 patients were examined successfully completed. The mean scanning time was 10.6±2.3 minutes. CE-CMRA displayed 164 segments of coronary which image quality were good or excellent.There was no significant difference in presenting proximal and middle segments of coronary artery principal branches between CE-CMRA and CCTA (P >0.05). There were 12 cases with significant stenosis(≥50%) of the principal branches examined by CCTA. CE-CMRA, however, only found 10 cases with significant stenosis(≥50%) of the principal branches. There was no significant difference in detecting stenosis length in both imaging modalities.The extent of stenosis was higher in CE-CMRA compared with CCTA.Conclusions:3.0 T CE-CMRA is a non-invasive imaging modality which is reliable on detcting significant stenosis in proximal and middle segments of coronary artery principal branches,and it can be used as a screening methods in coronary artery disease.And CE-CMRA also can be utilizd as an alter imaging modality in patients who were not suitable in CCTA examing. However,it is still limited in assessing stenosis of distal segment and small branches of coronary artery. Part III The clinical application and value of 3.0 tesla contrast-enhanced whole-heart coronary MR angiographyA comparative study with selective coronary arteriographyObjective To investigate the clinical application feasibility and value of 3.0 tesla whole-heart contrast enhanced coronary MR angiography (CE-CMRA) in three dimensions with free-breathing navigator-gated model.Methods 3.0 T CE-CMRA was utilizd to examine patients suspected coronary heart disease (CAD). Gd-BOPTA (0.2mmol/kg) was injected in vein with slow infusion rate(0.3ml/s) to perform enhancement. Datas was post-processed to obtain principal branches of coronary artery and picture's quality was evaluated. According to the results of selective coronary arteriography (SCAG),the diagnostic accuracy of CE-CMRA in CAD was judged by means of detecting significant stenosis(≥50%) of the principal branches based on AHA 9 segments classification of coronary artery.Results 23 patients were examined successfully completed in 26 cases.The mean scanning time was 10.4±2.1 minutes. Based on segment-level, SCAG demostrated 202 segments and CE-CMRA ruled out 178 segments(88.1%).The imaging quality of proximal and middle segments of coronary artery principal branches was super than distal segment. And there was no statistical significant between CE-CMRA and SCAG in evaluating proximal and middle segments of coronary artery principal branches. Based on patient-level,there were 9 positive cases and 14 negative cases examined by CE-CMRA, 11 positive cases and 12 negative cases examined by SCAG, respectively. The whole diagnose accordance rate of CE-CMRA was 91.3%(21/23) compared with SCAG. The sensitivity, specificity and negative predictive value were 81.8%,88.48%and 98.8% respectively.Conclusions 3.0 T CE-CMRA is a non-invasive patient-friendly imaging modality in CAD examination,and has better concordance with SCAG, which can be utilizd to detect significant stenosis in proximal and middle segments of coronary artery principal branches. However, it is still limited in assessing stenosis of distal segment and small branches of coronary artery.