单次屏气梯度-自旋回波在三维泌尿系尿路成像中的应用:与常规三维呼吸触发自旋回波技术的对比研究  

Three-Dimensional Breath-Hold MR Urography Using Gradient and Spin-Echo at 3T:Comparison with Conventional Respiratory-Triggered Fast Spin-Echo Technique

作　　者：王玮[1] 杨俊哲[1] 李玮[1] 赵凯[1] 薛珂 邱建星[1] WANG Wei;YANG Junzhe;LI Wei;ZHAO Kai;XUE Ke;QIU Jianxing(Department of Radiology,Peking University First Hospital,Beijing 100034,China)

机构地区：[1]北京大学第一医院医学影像科,北京100034 [2]上海联影医疗科技股份有限公司中央研究院,上海201807

出　　处：《中国医学影像学杂志》2022年第2期153-158,共6页Chinese Journal of Medical Imaging

摘　　要：目的通过与常规三维呼吸触发快速自旋回波尿路成像(RT-FSE MRU)比较,探究单次屏气梯度-自旋回波尿路成像(BH-GRASE MRU)在三维磁共振泌尿系尿路成像中应用的可行性及图像质量。资料与方法前瞻性连续收集2020年12月—2021年3月于北京大学第一医院行MRU扫描的上尿路积水患者32例,均于3.0T扫描得到冠状位3D RT-FSE MRU和3D BH-GRASE MRU图像。由1名影像医师计算肾盂、输尿管及膀胱相对周围组织的信号对比率(CR),比较两组MRU序列的实际采集时间。由另外2名影像医师应用5分评分标准独立评价两组图像的整体图像质量、伪影、背景抑制及尿路系统结构(双侧肾盏、肾盂、输尿管和膀胱)显示情况,分析尿路梗阻位置的形态特征。结果BH-GRASE MRU的采集时间为14.8 s,较常规RT-FSE MRU的(214.2±60.0)s显著缩短(t=18.188,P<0.001)。BH-GRASE MRU图像上尿路系统相对于周围组织的CR较RT-FSE MRU略减低(肾盂:0.81±0.09比0.85±0.10;t=3.110,P=0.004;输尿管:0.93±0.03比0.95±0.03;t=2.799,P=0.009;膀胱:0.93±0.03比0.96±0.02;t=6.599,P<0.001)。BH-GRASE MRU较RT-FSE MRU的整体图像质量、伪影及结构显示情况相似(Z=−1.377~1.473,P>0.05),但背景抑制略差于常规FSE MRU(Z=-3.998,P<0.001)。2名评分者主观评分一致性较好(Kappa=0.759~1)。5例患者3D RT-FSE MRU图像可见呼吸相关伪影(图像模糊),其中4例图像质量于3D BH-GRASE序列上得到改善。对于尿路梗阻处狭窄的形态特点分析,GRASE MRU对于梗阻良恶性的初步判断结果与常规FSE MRU一致。结论与常规3D RT-FSE MRU相比,BH-GRASE MRU在保证图像质量及影响诊断一致性的基础上,可以明显缩短扫描时间,并降低呼吸因素对图像质量的影响。通过单次屏气GRASE序列可以快速获得满足诊断需求的三维泌尿系尿路成像图。Purpose To assess the clinical feasibility and image quality of three-dimensional breath-hold gradient and spin echo magnetic resonance urography(BH-GRASE MRU)compared with three-dimensional respiratory-triggered magnetic resonance(RT-FSE MRU).Materials and Methods From December 2020 to March 2021,thirty-two consecutive patients with hydrops of the upper urinary tract were prospectively recruited.All patients underwent FSE MRU and GRASE MRU at 3T machine in Peking University First Hospital.The acquisition time and relative duct-to-periductal contrast ratios(CR)at pelvis,ureter,and bladder were quantitatively compared between the two MRU sequences by one radiologist.Two other radiologists independently and subjectively evaluated the overall image quality,artifacts,background suppression,duct visualization,and obstructive features(bilateral calyces,pelvis,ureter and bladder)of the two MRU images on a 5-point scale.Results The acquisition time of BH-GRASE MRU(14.8 s)was significantly decreased compared with that of RT-FSE MRU(214.2±60.0)s(t=18.188,P<0.001).The CR values of BH-GRASE MRU at urinary tract were slightly lower than that of RT-FSE MRU(pelvis:0.81±0.09 vs.0.85±0.10,t=3.110,P=0.004;ureter:0.93±0.03 vs.0.95±0.03,t=2.799,P=0.009;bladder:0.93±0.03 vs.0.96±0.02,t=6.599,P<0.001,respectively).Both reviewers found no significant differences in overall image quality,degree of artifacts,and duct visualization between the two methods(Z=−1.377−1.473,P>0.05),however,the background suppression of GRASE MRU was slightly worse than that of conventional FSE MRU(Z=−3.998,P<0.001).Inter-observer agreement of the qualitative results was good to perfect(Kappa=0.759−1).On 3D RT-FSE MRU,5 patients had image blur due to breath movement,in whom 4 patients had an image quality improvement on 3D-BH-GRASE MRU.There were no significant differences in the assessment of the obstructive features between the two MRUs.Conclusion Compared with the conventional 3D RT-FSE MRU,BH-GRASE MRU can significantly shorten scan time wit

关 键 词：磁共振成像 尿路造影术 梯度自旋回波 快速自旋回波 

分 类 号：R69[医药卫生—泌尿科学] R816.7[医药卫生—外科学]