| Objective:To evaluate the feasibility of the noncontrast-enhanced coronary magnetic resonance angiography on a 3T scanner.Methods:Totally 38 volunteers and 44 patients with clinically suspected coronary artery disease(CAD)underwent noncontrast-enhanced coronary MRA.Coronary artery was divided into 9 segments according to the American Heart Association(AHA)standard.The image quality of the noncontrast-enhanced MRA image was graded for each segment on a subjective four-point scale.The subjects were divided into two groups according to image quality score:the good image quality group and the poor image quality group.The age,heart rate,body mass index,end-expiratory diaphragm displacement,respiratory diaphragm motion amplitude,respiratory acceptance and scan duration was evaluated and compared between the two groups.Results:Totally 37 healthy volunteers and 44 CAD patients were enrolled in this study.The proximal and middle segment of left anterior descending(LAD)had a significant higher quality score than the distal segments.The proximal segment of left circumflex(LCX)coronary artery and right coronary artery(RCA)had a significant higher image quality score than the distal segments.In all,58 of the 81 subjects(71.6%)were scored as good and 23 as poor image quality.The age and scan duration showed no significant differences between the good image quality group and the bad image quality group.However,the heart rate,body mass index,end-expiratory diaphragm displacement and respiratory diaphragm motion amplitude is significantly lower in the good image quality group(p<0.05).And the respiratory acceptance is significantly higher in good image quality group(p<0.05).Conclusion:Noncontrast-enhanced MR Angiography on 3T is a feasible tool for visualization of the proximal and middle segments of coronary arteries,and the image quality can be optimized by controlling heart rate and respiration pattern in the future.Objective:To investigate the diagnostic performance of 3.OT magnetic resonance non-contrast coronary angiography for detection coronary artery disease with clinically significant stenosis,and to further evaluate the impact of heart rate BMI and respiratory acceptance on the diagnosis of coronary heart disease.Methods:A total of 56 patients with clinically suspected or confirmed coronary artery disease and planned to undergo invasive coronaryAngiography or coronary CTA were enrolled in this study.The MR angiography was performed on a 3.OT MR scanner using a navigator-gated,ECG-triggered whole-heart GRE sequence,with a T2 preparation and a fat suppression pre-pulse.Invasive coronary angiography was used as the "gold standard",and luminal stenosis ?50%was defined as clinically significant stenosis.Coronary artery MRA was assessed on the patient-based,vessel-based and segment-based level for detecting clinically significant stenosis.The inter-modality between coronary MRA and CTA was evaluated and the diagnostic performance for detecting coronary artery stenosis of the two noninvasive modalities was compared.Patients were divided into different groups according to heart rate,BMI and respiratory acceptance,compare the diagnostic performance of these groups were compared to investigate the impact factors on MRA diagnostic performance.The P value less than 0.05 was considered as statistically significant.Results:A total of 56 patients with clinically suspected or confirmed coronary artery disease were enrolled in the study.Of these,22 patients underwent invasive coronary angiography,46 underwent coronary CTA,and 12 underwent both coronary angiography and coronary CTA.In a patient-based analysis,the sensitivity,specificity,positive predictive value(PPV)negative predictive value(NPV)and diagnostic accuracy of non-contrast MRA for the detection of significant coronary artery stenosis is 78%,91%,90%,81%,85%.Compared with coronary CTA,there is no significant differences in the diagnostic accuracy between MRA and CTA,but the area under the receiver-operator characteristic curve(AUC)is higher than that of coronary MRA.In a segment-based analysis,the specificity and PPV is higher in patients with heart rate<70 bpm.There was no significant differences in the diagnostic performance of coronary MRA between the different BMI and respiratory acceptance groups.Conclusion:3.0T MR non-contrast coronary MRA has a high specificity for the diagnosis of clinically significant coronary stenosis.Heart rate maybe an impact factor on the diagnosis performance of MRA.Objective:To evaluate the feasibility of compression-sensing coronary artery MRA in coronary artery imaging,and to investigate the diagnostic performance of CS-MRA in detecting clinically significant coronary stenosis.Methods:A total of 50 patients with clinically suspected or confirmed coronary artery disease and planned to undergo cardiac MR were enrolled in this study.The MR angiography was performed on a 3.0T MR scanner using a navigator-gated,ECG-triggered whole-heart GRE sequence using compressed sensing technique.Coronary artery was divided into 9 segments according to the American Heart Association(AHA)standard.The image quality of the CS-MRA image was graded for each segment on a subjective four-point scale.Invasive coronary angiography was used as the "gold standard",and luminal stenosis ?50%was defined as clinically significant stenosis.The diagnostic performance of CS-MRA was assessed on the patient-based,vessel-based and segment-based level for detecting clinically significant stenosis.The inter-modality between coronary MRA and CTA was evaluated.The P value less than 0.05 was considered as statistically significant.Results:A total of 50 patients with clinically suspected or confirmed coronary artery disease were enrolled in the study.The mean scan duration of CS-MRA is 6.0±1.5 minutes.Of these,15 patients underwent invasive coronary angiography,27 patients underwent coronary CTA.The left anterior descending(LAD)and right coronary artery(RCA)had a significant higher quality score than left circumflex(LCX)coronary artery.The inter-modality agreement between CS-MRA and CTA on a segment-based level is 0.74.The inter-modality agreement between CS-MRA and CTA of LAD,LCX and RCA is 0.81?0.69 and 0.74.The proximal segment of left circumflex(LCX)coronary artery had a significant higher image quality score than the distal segments.In a segment-based analysis,the sensitivity,specificity,positive predictive value(PPV)negative predictive value(NPV)and diagnostic accuracy of CS-MRA for the detection of significant coronary artery stenosis is 860%,91%,64%,97%and 88%.Conclusion:Coronary MRA using compressed sensing technique can significantly shorten acquisition time,CS-MRA allows for the promising detection of coronary artery stenosis with high negative predictive value. |
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