Stankovic Zoran, Rössle Martin, Euringer Wulf, Schultheiss Michael, Salem Riad, Barker Alex, Carr James, Langer Mathias, Markl Michael, Collins Jeremy D
Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA,
Eur Radiol. 2015 Sep;25(9):2634-40. doi: 10.1007/s00330-015-3663-x. Epub 2015 Apr 8.
To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique.
Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement.
Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision.
Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies.
• 4D flow MRI, a non-invasive, non-contrast imaging technique, is feasible after TIPS. • Provides visualization and quantification of hepatic arterial, portal venous, collateral and TIPS haemodynamics. • Better understanding of liver blood flow changes after TIPS and patient management.
使用四维（4D）血流磁共振成像（MRI）这一非侵入性、无需造影剂的成像技术，评估经颈静脉肝内门体分流术（TIPS）患者门静脉和内脏动脉血流动力学的变化。
纳入11例行TIPS植入术的患者。在3特斯拉磁场下应用K-t GRAPPA加速无造影剂的肝脏血管系统4D血流MRI，加速因子R = 5。血流分析包括使用时间分辨三维粒子追踪的三维（3D）血流可视化和半定量血流模式分级。定量评估包括整个动脉和门静脉（PV）系统的峰值流速和净流量。在TIPS放置前24小时内和放置后4周进行MRI测量。
4D血流MRI的三维血流可视化显示图像质量良好，但PV血流存在一些小的局限性。定量分析显示，TIPS术后PV血流（术前562±373 ml/min，术后1831±965 ml/min）、肝动脉血流（176±132 ml/min vs. 354±140 ml/min）以及脾动脉和肠系膜上动脉的联合血流（770 ml/min vs. 1064 ml/min）均显著增加。分流血流评估显示，2例患者在TIPS翻修时确诊并治疗了狭窄。
4D血流MRI可能有潜力提供关于TIPS放置对肝脏灌注影响的新信息。它可能解释临床观察研究中的一些意外发现。
• 4D血流MRI是一种非侵入性、无需造影剂的成像技术，TIPS术后可行。• 可对肝动脉、门静脉、侧支和TIPS血流动力学进行可视化和量化。• 更好地理解TIPS术后肝脏血流变化及患者管理。
