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

Abstract

Purpose: To demonstrate the feasibility of detecting patency, stenosis, or occlusion of transjugular intrahepatic portosystemic shunts (TIPS) with 4D Flow MR. Materials and Methods: Sequential adult patients with TIPS were eligible for enrollment. A volumetric phase contrast sequence was used to image the TIPS. Particle tracing CINE images were used for qualitative assessment of stenosis. TIPS were segmented to generate quantitative data sets of peak velocity. Segmentation and quantitative measurement of flow throughout an entire TIPS stent defined technical success. Comparison was made to Doppler US. Venogram, when available, and 6-month clinical follow-up were used as reference standards. Results: 4D Flow MR was performed in 23 patient encounters, and was technically successful in 16/23 encounters. Three cases demonstrated both focal turbulence and abnormal velocities (>190cm/s or <90cm/s) on 4D Flow and had venogram confirmed stenosis (true positives). Seven cases had normal velocities and no turbulence on 4D Flow and all were confirmed negative with clinical follow-up or venogram (true negatives). Six cases had discordant 4D flow results, with abnormal velocities but no turbulence, or focal turbulence but normal velocities. All six discordant cases had no evidence of dysfunction with 6-month follow-up. Conclusion: 4D Flow MR can detect TIPS patency and stenosis, but requires further investigation before it can be used to assess for TIPS dysfunction.

Abdominal Applications of 4D Flow MRI

“…4D flow MRI correctly excluded flow abnormalities in seven patients without TIPS dysfunction. However, six patients without TIPS dysfunction had discordant 4D flow results demonstrating flow alterations [45]. These results indicate that further studies are needed to establish more specific 4D flow MRI criteria for monitoring TIPS function.…”

“…4D flow MRI may also be used to assess TIPS dysfunction (i. e. stenosis) by detection of focal turbulence and abnormal velocities [45,46]. A recent feasibility study aiming to detect TIPS dysfunction included 16 patients with a successfully performed 4D flow MRI [45]. Qualitative and quantitative flow properties (i. e. flow abnormalities like focal turbulence and peak velocities, respectively) were separately evaluated in each patient.…”

Time‐resolved 3D cine phase‐contrast magnetic resonance imaging (4D‐flow MRI) can quantitatively assess portosystemic shunt severity and confirm normalization of portal flow after embolization of large portosystemic shunts

“…However, US has some limitations, such as relatively low intra-and interobserver agreement, relatively poor reproducibility, limited field of view, limited visualization of complex structures, and image quality hampered by obesity or gastrointestinal gas. [7][8][9][13][14][15][16] In contrast, 4D-flow MRI is characterized by comprehensive data sampling of complete velocity and morphology, followed by objective retrospective data analysis. [6][7][8][9][10][11] No special expertise is needed in collecting and analyzing the data of 4D-flow.…”

“…[5][6][7][8] The usefulness of 4Dflow MRI in the PV area has been reported, and the procedural indications and therapeutic effects of portal intervention have been evaluated. [9][10][11] To our knowledge, there have been no reports describing the usefulness of 4D-flow MRI for the evaluation of portal hemodynamic patterns in PSS-related HE before and after PSS embolization. Here, we present our evaluation and management of two such cases.…”

A New Choice for the Use of the Stents for Transjugular Intrahepatic Portosystemic Shunt Creation: Viabahn ePTFE covered stent/bare metal stent combination

“…The development of shunt dysfunction mainly attributes to pseudointimal hyperplasia and thrombosis [26,27]. Back when BMS was widely utilized, shunt dysfunction occurred commonly due to bile leakage and extended liver parenchyma growth into the shunt via the mesh of bare stents.…”