# Portal vein hemodynamics measured by 4D flow MRI in predicting minimal hepatic encephalopathy in chronic hepatic schistosomiasis patients

## TL;DR

This study shows that 4D flow MRI can detect subtle changes in blood flow in the liver, which may help diagnose a hidden brain disorder in patients with chronic liver disease.

## Contribution

The study introduces 4D flow MRI as a non-invasive tool for diagnosing minimal hepatic encephalopathy in chronic hepatic schistosomiasis patients.

## Key findings

- MHE patients had significantly lower portal vein peak and mean velocities and higher portal area compared to non-MHE patients.
- Portal vein mean velocity showed the best diagnostic performance with high specificity and positive predictive value.
- 4D flow MRI parameters correlated with MHE, suggesting potential for non-invasive diagnosis and improved clinical outcomes.

## Abstract

Minimal hepatic encephalopathy (MHE) is a subclinical neuropsychological disorder frequently observed in chronic hepatic schistosomiasis (CHS) patients. Early diagnosis is challenging due to the subtle and nonspecific nature of MHE symptoms. Advances in magnetic resonance imaging (MRI), specifically 4D flow MRI, allow for non-invasive evaluation of portal vein hemodynamic parameters, offering a potential tool for diagnosing MHE.

To evaluate the application of portal vein hemodynamic parameters measured by 4D flow MRI in diagnosing MHE in CHS patients.

This prospective observational study included 118 CHS patients, divided into MHE (n = 52) and non-MHE (n = 66) groups. Portal vein hemodynamic parameters, including peak velocity, mean velocity, flow volume, and vessel area, were measured using 4D flow MRI. Correlation analyses were used to assess the relationship between these parameters and MHE. Diagnostic performances of portal vein hemodynamic parameters in MHE were also evaluated.

Patients with MHE exhibited significantly lower portal peak velocity (p < 0.001) and mean velocity (p < 0.001). Portal area (p < 0.001) was higher in MHE patients. Correlation analysis revealed significant associations between MHE and portal peak velocity (r = −0.389), mean velocity (r = −0.566), and area (r = 0.435). The diagnostic performance of portal peak velocity, mean velocity, and area in MHE demonstrated AUC of 0.70 (95% CI: 0.61–0.79) with specificity, sensitivity, negative predictive value (NPV) and positive predictive value (PPV) of 0.92, 0.47, 0.58, and 0.89, respectively; AUC of 0.82 (95% CI: 0.74–0.89) with specificity, sensitivity, NPV and PPV of 0.98, 0.64, 0.68, and 0.98, respectively; AUC of 0.74 (95% CI: 0.65–0.83) with specificity, sensitivity, NPV and PPV of 0.94, 0.46, 0.69, and 0.86, respectively.

4D flow MRI-derived portal vein hemodynamic parameters, particularly portal mean velocity, are significantly associated with MHE in CHS patients. These findings suggest that non-invasive imaging can provide insights for diagnosis and management of MHE, potentially improving clinical outcomes.