Mesenteric Ischemia: 2026 Update-<i>AJR</i> Expert Panel Narrative Review.

Abstract

Mesenteric ischemia (MI) represents a spectrum of vascular intestinal injuries for which delayed diagnosis remains the leading determinant of outcomes. Despite advances in multidetector CTA technology and endovascular therapy, substantial variation persists in how mesenteric ischemia is defined, imaged, interpreted, and incorporated into clinical pathways. This AJR Expert Panel Narrative Review provides radiologists with pragmatic guidance for mesenteric ischemia evaluation on imaging. Key issues considered include the pathophysiologic spectrum and diagnosis of acute mesenteric ischemia (AMI); CT protocol optimization (including the role of spectral CT); vascular pathologies that lead to occlusive or nonocclusive AMI; CT features associated with ischemia and necrosis; scoring systems for estimating necrosis likelihood; interventional and surgical management; evaluation of postischemic reperfusion; chronic mesenteric ischemia; and the emerging role of dedicated mesenteric stroke centers in reducing time to revascularization. A simplified four-phase framework is presented to illustrate the temporal progression of CT findings in occlusive arterial AMI from occlusion without visible bowel ischemia, to early ischemia, late ischemia, and irreversible transmural necrosis. The article concludes with consensus statements addressing image acquisition, interpretation, and reporting, with the aim of supporting radiologists who serve as first-line decision makers in the diagnosis and management of mesenteric ischemia.