Mesenteric Ischemia: A Comprehensive Review of the Role of Radiology in Diagnosis

Acute mesenteric ischemia (AMI) is an uncommon yet immensely fatal cause of abdominal pain with significant clinical consequences. Chronic mesenteric ischemia (CMI) accounts for a small proportion of intestinal ischemic cases but has significant clinical consequences. The majority of AMI occurs due to occlusive etiologies, including arterial and venous emboli and thrombus. Non-occlusive causes resulting in decreased blood supply to the intestines constitute the remaining cases. CMI results from an indolent formation of atherosclerotic plaques in the superior and inferior mesenteric arteries, pertaining to risk factors including hypertension, hyperlipidemia, and advanced age. Timely diagnosis of mesenteric ischemia is crucial and can aid in curtailing the associated morbidity and mortality. This review aims to provide an overview of the role of radiological modalities in diagnosing AMI and CMI. Computed tomography (CT) is the most widely accepted modality utilized to detect intestinal ischemia in clinically suspected cases. CT angiography (CTA) has shown the best results in identifying the vascular findings, delineating the primary etiologies. Additionally, several non-vascular CT findings have also been reported. Bowel wall thickening, mesenteric stranding, and ascites are common but non-specific findings that correlate poorly with disease severity. Pneumatosis intestinalis and porto-mesenteric venous gas, while not pathognomonic for ischemia, are highly specific in cases of high clinical suspicion. Exposure to radiation, nephropathy, and allergic reactions to contrast agents limit the use of CT in certain cases. Duplex ultrasound and magnetic resonance imaging have proved to be useful among these patients. However, each imaging modality has its limitations and challenges that need to be addressed. It is imperative to formulate definitive guidelines regarding the use of radiological tools compounded with other clinical and laboratory markers to help clinicians timely diagnose and treat mesenteric ischemia to enhance patient outcomes.