Association of spectral CT-derived hepatic fat fraction with pericoronary adipose tissue attenuation and high-risk coronary plaque features

Purpose To stratify the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) using the liver-to-spleen CT attenuation ratio and assess its correlation with hepatic fat volume fraction (FVF) via a spectral CT multi-material decomposition (MMD) algorithm and further explore the associations of MASLD severity and FVF with pericoronary adipose tissue (PCAT) phenotype and coronary high-risk plaque (HRP). Methods This retrospective study included patients who underwent coronary CT angiography (CCTA) for chest pain or suspected coronary artery disease, with concurrent contrast-enhanced upper-abdominal spectral CT in 2025. Of 733 consecutive patients, 568 were finally included after screening and stratified into non‑MASLD (n = 271), mild MASLD (n = 194), and moderate/severe MASLD (n = 103) based on the liver‑to‑spleen CT attenuation ratio obtained from unenhanced CT. FVF and liver volume were measured with the MMD algorithm. PCAT fat attenuation index (FAI) and PCAT volume were measured across three major coronary arteries, and HRP was assessed on CCTA. Multivariable logistic regression models were built to assess the relationship between MASLD severity and HRP, with prespecified subgroup analyses. Results MASLD severity was positively associated with FVF, liver volume, and multiple metabolic and inflammatory markers, and inversely associated with high-density lipoprotein cholesterol and the alanine aminotransferase/aspartate aminotransferase ratio (all p < 0.001). LAD-PCAT-FAI, LCX-PCAT-FAI, and RCA-PCAT-FAI differed significantly among the three groups (all p < 0.05). In the full-cohort Model 2 (n = 568), FVF was associated with total PCAT volume (B = 0.033 cm³, p = 0.004), but not with mean PCAT-FAI (B = − 0.007 HU, p = 0.926). The prevalence of HRP was 20.7%, 33.5%, and 37.9% in the non-MASLD, mild MASLD, and moderate/severe MASLD groups, respectively (p < 0.001). Compared with non-MASLD, the ORs for mild and moderate/severe MASLD were 1.935/2.340 in Model 1, 1.834/2.827 in Model 2, and 1.986/2.750 in Model 3. Subgroup interaction P values were 0.004 for age, 0.027 for hypertension, and 0.050 for diabetes. Conclusion Spectral CT-derived FVF was associated with MASLD severity. FVF was associated with total PCAT volume, but not with mean PCAT-FAI. MASLD severity was associated with HRP. An integrated one-stop heart-liver CT assessment is feasible and may facilitate the concurrent imaging assessment of hepatic fat and coronary features.