Introduction

The whole-heart coronary MRA technique has advantages ofnoninvasive, contrast agent-free, and radiation-free to evaluatecoronary artery disease.Compressed Sensing (CS) is a novel technique to accelerate scanning with flexible acceleration factors(AFs) settings.Atrial fibrillation has been widely concerned as a common complication ofdiaphragm navigator-based free-breathingcoronary MRA,which might increase scanning difficulty and harm image quality.The purpose of this study is to explore if the whole-heart coronary MRA with different compressed sensing AFscould be applied in patients withatrial fibrillation.

Methods

This study was approved by the institutional IRB. 206 patients with sinus rhythm(SR)and 50 patients with atrial fibrillation(AF)were enrolled and under went whole-heart coronary MRA on a 1.5T MR scanner (Ambition, Philips Healthcare, the Netherlands) with a 32-channel body coil. The whole-heart coronary MRA was based on a free-breathing electrocardiogram-triggered navigator-gated steady-state free precession sequence, which was accelerated by CS^[1]. The MRA protocols with different CS AFs were implemented in random orders for each subject. The electrocardiogram trigger delay was identified by visualizing the quiescent period of the right coronary artery (RCA) using a 100 phases breath-hold cine image in the two-chamber view (temporal resolution 7.5ms). Three radiologists independently assessed the image quality on nine branches of the coronary artery through a four-point scale (1=poor, 2=medium, 3=good, 4=excellent) subjective score system. The scored coronary artery included left main coronary artery (LM),left anterior descending coronary (LAD), left circumflex artery (LCX),posterior descending artery (RCA) at proximal (index 1), middle/distal (index 2), distal (index 3) positions.After the consistency test, the mean values of image quality scores were compared between two groups using anMann-Whitney Utest

Results

The representative images of the right coronary artery and left coronary artery with different acceleration schemes were shown in figure 1, figure 2, and figure 3. The quality scores of images with CS AFs of 2,4were in table1and table2.There was no statistical difference in image quality inLM, LAD1, LAD2, LAD3,LCX1,LCX2,RCA1,RCA3(p ＞0.05) except RCA2(p<0.05). The image quality scores with CS AFs of 6 were in table3, There were no statistical differences in image quality in LM, LAD1, LAD2, LAD3,LCX1,LCX2,RCA1,RCA2(p＞0.05), and slight differences in image quality in RCA3(p <0.05).When the CS AFs increased, the image quality was reduced(table1,2,3).

Discussion

Despite the arrhythmia in patients with atrial fibrillation, there was little difference in image quality compared with sinus rhythm except for a few vessels.This suggested that whole-heart coronary MRA with CS technique was also suitable for atrial fibrillation patients. Further studies are necessary to evaluate its diagnostic accuracy compared with the gold standard digital subtraction angiography (DSA).

Conclusion

This study showed that whole-heart coronary MRA with different CS AFs in sinus rhythm and atrial fibrillation patients could get approximately the same image quality, which suggested CS accelerated coronary MRA was a promising and valuable non-invasive clinical method for the diagnosis of coronary artery disease.

Acknowledgements

On this occasion, there is no one we wish to acknowledge.