对比自由呼吸Star-VIBE序列与呼吸末屏气C-VIBE序列胸部MR图像质量

Comparison on chest MR image quality using free-breathing Star-VIBE and breath-hold C-VIBE sequences

目的比较分析以自由呼吸Star-VIBE序列与呼吸末屏气C-VIBE序列采及胸部MRI的图像质量。方法对20例患者行胸部MR检查,采集呼气末屏气C-VIBE(C-VIBE)和自由呼吸Star-VIBE(Star-VIBE)序列图像。于肺动脉干水平分别测量升主动脉、肺动脉干、降主动脉的信号强度(SI)和标准差(SD),计算图像信噪比(SNR)和SI变异系数(CV)。对图像质量进行主观评分。比较2个序列图像的SNR、CV及主观评分差异。结果Star-VIBE图像升主动脉、肺动脉干及降主动脉SNR值均高于C-VIBE(t=-4.87、-3.38、-9.42,P均<0.05),而SI CV均低于C-VIBE图像(t=5.52、3.67、8.04,P均<0.05)。Star-VIBE图像的主观评分高于C-VIBE图像(Z=-3.74,P<0.05)。结论自由呼吸Star-VIBE序列胸部MRI的图像质量优于呼气末屏气C-VIBE序列。

Objective To compare the image quality of chest MRI collected with free-breathing radial stack-of-stars volume interpolated breath-hold examination(Star-VIBE)sequence and conventional volume interpolated breath-hold examination sequence(C-VIBE)at the end of breath.Methods Twenty patients who underwent chest MR examination were prospectively collected,and the images were obtained with breath-hold C-VIBE sequence(C-VIBE)and free-breathing Star-VIBE sequence(Star-VIBE),respectively.The signal intensity(SI)and standard deviation(SD)of ascending aorta,main pulmonary artery and descending aorta were measured at the level of main pulmonary artery.Then signal-to-noise ratio(SNR)of images and coefficient of variation(CV)of SI were calculated.The image quality was subjectively scored.SNR,CV and subjective scores of the images were compared between 2 sequence.Results The image SNR of ascending aorta,main pulmonary artery and descending aorta of Star-VIBE sequence were higher than those of C-VIBE sequence(t=-4.87,-3.38,-9.42,all P<0.05),while the CV of SI with Star-VIBE sequence were lower than those of C-VIBE sequence(t=5.52,3.67,8.04,all P<0.05).The subjective scores of Star-VIBE sequence were significantly higher than those of C-VIBE sequence(Z=-3.74,P<0.05).Conclusion Using free breathing Star-VIBE sequence,the image quality of chest MRI was better than that with C-VIBE sequence at the end of breath.