RESUMO
Objective To investigate the techniques and influence factors for the respiratory navigator echo triggered whole-heart coronary MR angiography(WH-CMRA)and evaluate its application in visualizing coronary arteries and the image quality.Methods Ninety two volunteers were acquired with WH-CMRA at 3 T MR scanner using respiratory navigator-echo gated TFE sequence.Imaging quality was visually graded as 0—Ⅳ grade according to the visual inspection,average length,diameter and sharpness of coronary arteries.The correlation between the imaging quality and respiratory pattern,heart rate and navigator efficiency was analyzed.Results The imaging quality in 92 cases was that 28 were graded as Ⅳ, 53 were graded as Ⅲ,9 were graded as Ⅱ and 2 were graded as Ⅰ.The successful rate of scan was 88% (81/92).The imaging quality is mainly graded as Ⅳ when the heart rate was less than 75 beats per minute (bpm)and the sharpness of vessel was(48?11)%.When heart rate was more than 75 bpm,the image quality was mostly graded as Ⅲ and the sharpness was(33?15)%.The correlation between heart rate and imaging quality score was negative(r=-0.726,P0.05).Conclusion 3 T WH-CMRA technique could facilitated the visualization of whole coronary arteries at free breathing but having indications on heart rate.