The Feasibility of Using Volumetric Phase-Contrast MR Imaging (4D Flow) to Assess for Transjugular Intrahepatic...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Transjugular intrahepatic portosystemic shunt (TIPS) creation is a common procedure for managing portal hypertension.
• Monitoring TIPS patency and detecting complications like stenosis or occlusion is crucial for patient outcomes.
• Current monitoring methods may have limitations, necessitating advanced imaging techniques.

Purpose of the Study:

• To evaluate the feasibility of using four-dimensional (4D) flow MR imaging for assessing the patency, stenosis, or occlusion of TIPS.
• To compare the diagnostic accuracy of 4D flow MRI with Doppler ultrasound and venography.

Main Methods:

• A volumetric phase-contrast sequence was employed for 4D flow MRI of TIPS in adult patients.
• Particle tracing and quantitative velocity measurements were used for qualitative and quantitative assessments.
• Technical success was defined by successful segmentation and flow measurement.
• Doppler US, venography, and clinical follow-up served as reference standards.

Main Results:

• 4D flow MRI was technically successful in 69.6% of patient encounters (16/23).
• The technique correctly identified stenosis in 3 cases (true positives) based on focal turbulence and abnormal velocities.
• It accurately identified patent TIPS in 7 cases (true negatives) with normal flow patterns.
• Six cases showed discordant results, with no evidence of dysfunction during follow-up.

Conclusions:

• 4D flow MR imaging is a feasible technique for detecting TIPS patency and stenosis.
• Additional research is necessary to establish its role in assessing TIPS dysfunction.
• The study highlights the potential of 4D flow MRI as a non-invasive tool for TIPS monitoring.