非对比剂增强MR血管成像联合多反转空间标记脉冲技术在肺动脉成像的可行性研究

摘要

目的：评估非对比增强磁共振血管成像联合多反转空间标记脉冲技术(SLEEK-MRA)在肺动脉成像中应用的可行性，并探讨最佳成像效果的血流抑制反转时间(BSP-TI)。材料与方法对14例健康志愿者通过SLEEK-MRA序列应用不同的血流抑制反转时间(BSP-TI)分别进行肺动脉成像。扫描后的图像由2名放射学诊断医师分别对4级肺动脉(①肺动脉主干；②左右主肺动脉主干；③叶间动脉；④段间动脉)通过4分法进行主观评分，同时计算图像的相对信噪比(SNR)及对比信噪比(CNR)。结果13例志愿者成功完成检查，其中1名志愿者因情绪紧张呼吸过快且不规则导致检查失败。各级别肺动脉图像质量主观评分BSP-TI=700 ms及900 ms均优于500 ms、1100 ms、1300 ms，差异均具有统计学意义(P值均<0.05)，BSP-TI=700 ms及900 ms之间无明显统计学差异；BSP-TI=700 ms时，肺动脉干及左、右肺动脉主支图像对比信噪比及相对信噪比优于500 ms (P<0.05)，与900 ms、1100 ms、1300 ms无明显统计学差异；BSP-TI=1100 ms及1300 ms时产生静脉污染(5/13，9/13)。结论非对比剂增强SLEEK-MRA序列用于肺动脉成像可清晰显示肺动脉主干及外周细小分支动脉，700 ms为肺动脉成像效果的最佳BSP-TI。%Objective:The purpose of this study was to demonstrate the feasibility of a non-contrast-enhanced magnetic resonance angiography (MRA) sequence, Multiple Inversion Pulses Sequence (SLEEK), used in pulmonary artery, and to explore the optimum blood-suppression inversion time (BSP-TI) for good image quality. Materials and Methods: Fourteen healthy volunteers who had no contraindications to MRI and no recent health problems or surgeries were recruited in the study. All subjects were performed at a 1.5 T MRI system for assessing pulmonary artery. The ability to present four segments (①pulmonary trunk.②main right and left pulmonary arteries.③interlobar arteries.④ segmental arteries bilaterally) were evaluated independently by two radiologists using a four-point scale. Relative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) also were determined. Results:Thirteen volunteers were successfully performed SLEEK MRA, only one volunteer failed because of irregular respiration. The subjective image quality was signiifcantly better with BSP-TI 700 ms and 900 ms than with 500 ms, 1100 ms and 1300 ms (P<0.05). The CNR and relative SNR of pulmonary artery were significantly better with BSP-TI 700 ms than with 500 ms (P<0.05), though showed no signiifcantly better than with 900 ms, 1100 ms and 1300 ms (P>0.05), taking into the pulmonary venous contamination consideration (1100 ms 5/13, 1300ms 9/13), the image quality with BSP-TI 700 ms for pulmonary artery was signiifcantly better than with others. Conclusions:Performing non-contrast-enhanced MRA with SLEEK sequence can achieve clear vessel delineation both in central and peripheral pulmonary arteries with the BSP-TI of 700 ms.