The Value Of Respiratory Trigger Gating In Optimizing The Quality Of MRI Images Of Brachial Plexus

Purpose:Under the fixed scanning time,evaluate whether the respiratory trigger gating technology can reduce the respiratory motion artifacts,so as to improve the image quality of oblique sagittal brachial plexus MRI sequence and improve the clarity of brachial plexus display.Materials and methods:In this study,24 patients who were examined in our hospital from September to December 2019 were selected.3.0T MRI was used to obtain oblique sagittal images with and without respiratory trigger gating.Then two radiologists blindly evaluated the images of non-RT and RT sequence.The subjective scoring criteria include the ghosting artifact,the brachial plexus conspicuity,diagnostic confidence and the contrast between nerve and surrounding tissues.Nerve conspicuity at three distinct plexus levels were summed to calculate an overall image quality score.The subjective scores of each category between non-RT and RT were compared by using the marginal proportional odds logistic regression model.The kappa consistency coefficient was used to assess interobserver agreement.Result:With respiratory triggering(RT),the subjective scores of the overall image quality,artifact,confidence in the diagnosis of brachial plexus and the contrast between nerve and surrounding tissues were significantly better than those of non-RT.With RT,the image artifact was reduced(reader A: OR=0.18,95%CI:0.02-1.48;reader B: OR=0.13,95% CI:0.02-0.92),improved overall image quality(reader A: OR=25.67,95% CI:2.20-299.14;reader B:OR=36.23,95%CI:3.56-368.28),increased diagnostic confidence(reader A: OR=17.38,95%CI:2.80-107.87;reader B: OR=14.99,95%CI:2.90-77.50)and contrast between nerve and surrounding tissues(reader A:OR=21.39,95%CI:1.91-239.21;reader B: OR=15.03,95%CI:1.32-171.38),P < 0.05,the difference was statistically significant.Interobserver agreement of the two doctors on all aspects of the brachial plexus MRI image were fairly good or excellent(k = 0.61-0.85).Conclusion:Respiratory triggering technology can effectively reduce the respiratory motion artifacts in the process of MRI,improve the MRI images quality of brachial plexus,and improve the accuracy of image diagnosis.