Introduction

Whole heart, non-contrast agent coronary angiography (MRCA) with long scanning time is a major obstacle for clinical examination. Compressed SENSE technique has been widely used in clinical examinations. Meanwhile, it can ensure the quality of the image and reduce the scanning time significantly.[3] The aim of this study was to explore the feasibility of the whole heart non-contrast MRCA based on compressed SENSE technology and explore the best accelerator factors for clinical and research use.

Materials and Methods:

This study was approved by the Institutional Review Board and all participants signed written informed consent. Patients who had completed coronary artery CTA (CCTA) examination in our hospital were underwent whole-heart non-contrast coronary magnetic resonance angiography on 3.0T MR scanner (Ingenia CX, Philips, Netherland) All patients were suspected for acute coronary syndrome. They received four different scanning sequences: Conventional sequence SENSE2 (S2), the other three groups of sequences used compressed SENSE technology, acceleration factors were 4, 5, 6 (CS4, CS5, CS6). The S2 was considered as the control sequence and CCTA images were taken as the gold standard. Subjective image quality was scored by two experienced doctors and the scoring was based on a four-point system: (1) 4 points, clear vascular display, sharp lumen boundary; (2) At 3 minutes, the vascular display was sufficient and the lumen boundary was slightly blurred; (3) 2 marks, vascular visible, lumen boundary blurred, affecting lumen evaluation; (4) 1 point, the artifact was severe, and the lumen could not be evaluated or visible. The image quality score ≥3 was considered as good image quality and high diagnostic reliability. The image with a score of 1 was difficult to diagnose. The signal contrast CR value was measured and calculated, and the vessel with a score of 1 was abandoned，Record the CR of each segment, CR=(μ_vessel-μ_myocardium)/[(σ_vessel²-σ _myocardium²)^-2], μ is the average signal intensity of the corresponding tissue, and σ is the variance of the corresponding tissue.The image quality of different segments of coronary arteries were compared among the four sequences.

Results

Twenty-eight patients were included in this study, and the subjective scored of image quality were 4 points with 294 segments, 3 points with 414 segments, 2 points with 246 segments, and 1 point with 166 segments. There were statistically significant differences in the subjective scores of each segment of coronary artery among groups S2, CS4, CS5 and CS6 except for the distal segment of LCX (P < 0.05). Further pin-wise comparison showed that the subjective scores of each segment of CS6 group were lower than those of S2 and CS4 group (P < 0.05)（Table 1）. There were statistically significant differences in CR values between S2, CS4, CS5 and CS6 coronary artery segments in middle RCA and near LAD (P < 0.05), but there were no statistically significant differences in other segments (P > 0.05). Further pairwise comparison showed that the CR value of CS6 group was lower than S2 group (P < 0.05). The CR value of CS6 group was lower than S2 group and CS4 group (P < 0.05)（Table 2）. CS4 and CS5 had no statistical difference in image quality compared with S2, and Compared with S2 and CS4, CS6 had statistically significant difference.The average scanning time of each sequence is 344.10±47.39, 270.36±37.07, 215.18±30.39 180.39±25.06, and the CS5 and S2 are shorter than the time by about 37.5%.

Conclusion

Compressed SENSE technology can shorten the examination time ensuring the image quality. When the acceleration factor is 5, the time is obviously shortened and the image quality can be used in clinical practice.

Acknowledgements

No acknowledgement found.

References

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