Closer Association of Liver Stiffness Than Liver Fat Content With Imaging-Derived Neurovascular Coupling in a...

Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasingly linked to cognitive decline, yet the hepatic factors associated with imaging-derived neurovascular coupling (NVC) remain unclear. This study aimed to investigate whether liver stiffness or liver fat content was more closely associated with resting-state CBF-ReHo surrogate measures.

A total of 130 participants including 98 MASLD patients and 32 age- and education-matched healthy controls (HCs) underwent clinical assessment, neuropsychological testing, and multi-modal MRI. Liver stiffness and fat content were quantified using MR elastography (MRE) and MRI-proton density fat fraction (PDFF). Imaging-derived NVC was assessed using global cerebral blood flow (CBF)-regional homogeneity (ReHo) coupling and voxel-wise CBF/ReHo ratios, interpreted as resting-state surrogates rather than direct stimulus-evoked NVC. Multivariable regression and exploratory mediation analyses were employed.

Compared to HCs and patients with lower liver stiffness (MASLD_low), those with higher liver stiffness (MASLD_high) showed reduced global CBF-ReHo coupling and altered CBF/ReHo ratios, primarily localized to the bilateral superior temporal pole/superior temporal gyrus (TPOsup). In multivariable regression, liver stiffness remained independently associated with TPOsup CBF/ReHo ratios (p < 0.001). Exploratory mediation analysis showed a statistically significant indirect association between hepatocellular injury markers and TPOsup CBF/ReHo ratios involving MRE-derived liver stiffness (95% CI: 0.0795-0.2790).

Within this cohort and the observed PDFF range, MRE-derived liver stiffness was more closely associated with imaging-derived NVC surrogate measures than liver fat content in MASLD. These findings are hypothesis-generating and require validation in longitudinal studies.