Abstract Objective: To evaluate the predictive value of the perivascular fat attenuation index (FAI) surrounding the superior mesenteric artery (SMA) on non-contrast CT for SMA abnormalities in acute abdominal pain and FAI's incremental utility in risk models. Methods: This retrospective study included 262 acute abdominal pain patients (77 with SMA abnormalities, 185 controls) admitted between January 2020 and December 2025. All underwent non-contrast and contrast-enhanced CT within 48 h.