Splanchnic hemodynamic parameters measured with 4D flow MRI can diagnose severe portal hypertension

Objectives: To assess the diagnostic performance of splanchnic hemodynamic parameters measured with 4D flow MRI for diagnosis of severe portal hypertension (PH; hepatic venous pressure gradient (HVPG) ≥ 12 mmHg), and prediction of liver decompensation in patients with chronic liver disease. Materials and methods: Our single-center prospective study (2018–2022) enrolled patients undergoing transjugular liver biopsy with wedge HVPG measurement for abdominal 4D flow MRI (MRI-HVPG interval = 28 ± 18 (1–78) days). 4D flow MRI was acquired at 1.5 T, 10 min. after injection of gadoxetic acid, with a prototype sequence in coronal-oblique orientation (VENC = 60 cm/s). Multiple observers manually segmented the portal, superior mesenteric, splenic and middle hepatic veins, supraceliac aorta, celiac trunk, hepatic and splenic arteries. Time-averaged vessel cross-section area, through-plane time-averaged velocity and flow, and peak velocity were compared between patients with/without severe PH, and with/without future liver decompensation by Mann–Whitney U test and ROC analysis. Results: 50 patients (M/F: 26/24, age = 52 ± 15 years) were included, of which 47 had clinical follow-up 1084 ± 618 days after MRI. Twenty-three of 50 (46%) patients had PH, 8/50 (16%) had severe PH, and 12/47 (26%) had decompensation. Celiac trunk peak velocity [AUC (95% CI) = 0.90 (0.80–0.99)] and superior mesenteric vein area [AUC (95% CI) = 0.88 (0.77–0.99)] identified severe PH with the highest diagnostic performance. A logistic regression model combining celiac trunk peak velocity and superior mesenteric vein flow identified severe PH with AUC (95% CI) = 0.95 (0.88–1.00), sensitivity = 100%, specificity = 89%. Hepatic [AUC (95% CI) = 0.74 (0.57–0.92)] and splenic artery [AUC (95% CI) = 0.74 (0.52–0.96)] area, celiac trunk [AUC (95% CI) = 0.70 (0.51–0.89)] and superior mesenteric vein [AUC (95% CI) = 0.72 (0.55–0.89)] flow predicted liver decompensation with good diagnostic performance. Conclusion: Splanchnic 4D flow MRI measurements have excellent performance for diagnosing severe PH and good performance for predicting liver decompensation. Key Points: Question Noninvasive detection of severe portal hypertension (hepatic venous pressure gradient ≥ 12 mmHg) is important to prevent bleeding, decompensation, and death in patients with chronic liver disease. Findings Splanchnic hemodynamic measurements by 4D flow MRI can identify patients with severe portal hypertension and predict liver decompensation with excellent/good diagnostic performance. Clinical relevance 4D flow MRI can potentially be integrated into the clinical MRI protocols of patients with liver cirrhosis.