Normal and Altered Three-dimensional Portal Venous Hemodynamics in Patients with Liver Cirrhosis
Normal and Altered Three-dimensional Portal Venous Hemodynamics in Patients with Liver Cirrhosis
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DOI：
10.1148/radiol.11110127
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发表时间：
2012-03-01
期刊：
影响因子：
19.7
通讯作者：
Markl, Michael
中科院分区：
文献类型：
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作者：
Stankovic, Zoran;Csatari, Zoltan;Markl, Michael
目的：以多普勒超声(US)为标准，比较时间分辨三维(3D)相衬磁共振(MR)成像和三向速度编码(血流敏感四维[4D]MR成像)，研究肝硬变患者门静脉三维血流动力学的变化，并与年龄匹配的健康对照组和健康青年志愿者进行比较。材料与方法：这项前瞻性研究得到当地伦理委员会的批准，并征得所有参与者的书面知情同意。应用3-T磁共振系统(空间分辨率约2 mm(3)；时间分辨率约45毫秒)，对20名肝硬变患者、20名年龄匹配的健康对照组和21名健康青年志愿者的门静脉三维血流动力学进行了评估。利用三维流线和时间分辨颗粒轨迹分析了流动特性。定量分析是通过回顾评估区域峰值和平均血流速度、流量和血管面积进行的。以彩色多普勒超声为参考标准。组间比较采用独立样本t检验或Wilcoxon-Mann-Whitney检验。结果：门静脉血流动力学三维成像获得成功，18例患者和35例志愿者门静脉血流动力学完全显示，但肝内左支血管显示受限(A组87%，B组89%)。在几乎所有的最大和平均血流速度、血流量和血管面积上，4D磁共振成像与多普勒超声均有中等但显著的相关性(r=0.24-0.64，P=.001-.044)。在磁共振成像中，除了血管面积外，肝内血流速度和流量被显著低估，多普勒超声表现为更低(P<；.001至P=.045)。6例脐静脉再通，1例肠系膜上静脉血流逆转。结论：血流敏感的4D磁共振成像可作为评价肝硬变患者门静脉系统血流动力学的一种有前途的替代技术，并可作为一种评价血流特征的病理改变的手段。
Purpose: To compare time-resolved three-dimensional (3D) phase-contrast magnetic resonance (MR) imaging with three-directional velocity encoding (flow-sensitive four-dimensional [4D] MR imaging), with Doppler ultrasonography (US) as standard of reference, for investigating alterations in 3D portal venous hemodynamics in patients with liver cirrhosis compared with healthy age-matched control subjects and healthy young volunteers.Material & Methods: This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. Three-dimensional portal venous hemodynamics was assessed, employing flow-sensitive 4D MR imaging with a 3-T MR system (spatial resolution, approximately 2 mm(3); temporal resolution, approximately 45 msec) in 20 patients with hepatic cirrhosis, 20 healthy age-matched control subjects, and 21 healthy young volunteers. Flow characteristics were analyzed by using 3D streamlines and time-resolved particle traces. Quantitative analyses were performed by retrospectively evaluating regional peak and mean velocities, flow volume, and vessel area. Doppler US was used as standard of reference. Independent-sample t tests or Wilcoxon-Mann-Whitney tests were applied for comparing each subject group. Paired-sample t tests or Wilcoxon tests were applied when comparing MR imaging and US.Results: Three-dimensional visualization of portal venous hemodynamics was successful, with complete visualization of the vessels in 18 patients and 35 volunteers, with limitations in the left intrahepatic branches (87%, reader A; 89%, reader B). A moderate but significant correlation was observed between 4D MR imaging and Doppler US in nearly all maximum and mean velocities, flow volumes, and vessel areas (r = 0.24-0.64, P = .001-.044). With MR imaging, significant underestimation was observed of intrahepatic flow velocities and flow volumes, except vessel area, which Doppler US represented as even lower (P < .001 to P = .045). Six patients had collateralization with reopened umbilical vein, while one had flow reversal in the superior mesenteric vein visible at MR imaging only.Conclusion: Flow-sensitive 4D MR imaging may constitute a promising, alternative technique to Doppler US for evaluating hemodynamics in the portal venous system of patients with liver cirrhosis and may be a means of assessing pathologic changes in flow characteristics.