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

Non-contrast-enhanced MR angiography using spatial labeling with multiple inversion pulses sequence imaging in pulmonary artery: a feasibility study

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BSPTI=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=700ms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-contrastenhanced MRA with SLEEK sequence can achieve clear vessel delineation both in central and peripheral pulmonary arteries with the BSP-TI of 700 ms.