Résumé
【Objective】 To investigate the improvement of signal uniformity in cardiac magnetic resonance image by adjusting the transmit gain (TG). 【Methods】 For this study we recruited 11 volunteers for cardiac MR scans between July and September 2018. The scanner of US GE Discovery 750 3.0T superconducting MRI was used. We divided the volunteers into normal group and overweight group according to their individual BMI index. The imaging sequences consisted of the black blood double inversion recovery sequence (T1 weighted image and T2 weighted image) and breath-holding black blood three-inversion recovery sequence (FST1 weighted image and FST2 weighted image). All sequences were performed across different TG values, including 150, 160, 170, 180, and 190. The images’ quality was scored by two experienced radiologists using a four-point system based on the blinding principle. The paired variance analysis was made to compare the image quality of different TG groups. 【Results】 We observed consistent results in both normal and overweight groups. The optimal TG value was 160 for black blood triple inversion recovery sequence and 170 for black blood double inversion recovery sequence. 【Conclusion】 Adjusting the TG value can improve the signal uniformity of the myocardium, thereby improving the quality of images.