Four-dimensional Flow MRI as a Marker for Risk Stratification of Gastroesophageal Varices in Patients with Liver Cirrhosis

Abstract

To assess the feasibility of four-dimensional (4D) flow MRI as a noninvasive imaging marker for stratifying the risk of variceal bleeding in patients with liver cirrhosis. Materials and Methods: This study recruited participants scheduled for both liver MRI and gastroesophageal endoscopy. Risk of variceal bleeding was assessed at endoscopy by using a three-point scale: no varices, low risk, and high risk requiring treatment. Fourdimensional flow MRI was used to create angiograms for evaluating visibility of varices and to measure flow volumes in main portal vein (PV), superior mesenteric vein, splenic vein (SV), and azygos vein. Fractional flow changes in PV and SV were calculated to quantify shunting (outflow) from PV and SV into varices. Logistic analysis was used to identify the independent indicator of highrisk varices. Results: There were 23 participants (mean age, 52.3 years; age range, 25-75 years), including 14 men (mean age, 51.7 years; age range, 25-75 years) and nine women (mean age, 53.2 years; age range, 31-72 years) with no varices (n = 8), low-risk varices (n = 8), and high-risk varices (n = 7) determined at endoscopy. Four-dimensional flow MRI-based angiography helped radiologists to view varices in four of 15 participants with varices. Independent indicators of high-risk varices were flow volume in the azygos vein greater than 0.1 L/min (P = .034; 100% sensitivity [seven of seven] and 62% specificity [10 of 16]) and fractional flow change in PV of less than 0 (P , .001; 100% sensitivity [seven of seven] and 94% specificity [15 of 16]). Conclusion: Azygos flow greater than 0.1 L/min and portal venous flow less than the sum of splenic and superior mesenteric vein flow are useful markers to stratify the risk of gastroesophageal varices bleeding in patients with liver cirrhosis.

Noninvasive Diagnostics for Portal Hypertension: A Comprehensive Review

“…57,58 Moreover, a small proof-of-concept study using four-dimensional (4D) flow MRI linked azygos flow to high-risk varices. 59 Another proof-of-concept study (58% CTP stage B/C; 67% CSPH) used PC-MRI to assess total liver blood flow by subtracting infra-from suprahepatic caval blood flow in 12 patients with ACLD. Furthermore, the authors also measured portal venous blood flow and calculated hepatic artery fraction (i.e., a measure of the increased arterial perfusion/splanchnic vasodilatation in patients with ACLD), the latter showing a direct correlation of moderate strength (Pearson's r ¼ 0.78) with HVPG.…”

Visualization of flow dynamics in the portal circulation using 320-detector-row computed tomography: a feasibility study

“…Regarding portal-hypertension-related diseases, IR treatments raise serious post-therapeutic concerns that include the emergence of ascites, deterioration of other varices, portal thrombosis, and liver failure [16,17]. Although each modality has drawbacks, recent US and 4D flow MRI studies have revealed the relationship between portal flow and the deterioration of gastroenteric varices and liver function [2,[18][19][20]. IR treatments can alter the flow dynamics of the portal circulation between pre-and post-therapy, resulting in changed liver function [18,20].…”

Quantification of the Hemodynamic Changes of Cirrhosis with Free‐Breathing Self‐Navigated MRI

“…Phase‐contrast MRI with three‐directional velocity encoding and cardiac gating (4D flow) allows for time‐resolved quantification of blood flow across any plane, definable before or after the acquisition, within the imaging volume 13–22 . Major challenges to routine use in abdominal imaging include long scan duration and artifact from respiratory and cardiac motion.…”