CT patterns of acute enterocolitis - a practical guide for the emergency radiologist

Acute enterocolitis encompasses a broad spectrum of conditions affecting the small and large bowel, frequently presenting with nonspecific symptoms such as abdominal pain, diarrhea, fever, and vomiting. Given the clinical overlap among infectious, inflammatory, immune-mediated, vascular, and miscellaneous etiologies, imaging plays a pivotal role in refining the differential diagnosis, identifying complications, and guiding timely management. Computed tomography (CT), owing to its accessibility and rapid acquisition, remains the cornerstone of imaging evaluation in acute settings. CT enables detailed assessment of bowel wall morphology, disease distribution, vascular involvement, and extraintestinal manifestations. While ancillary imaging modalities have a role in select scenarios, this review emphasizes a CT-focused approach tailored for acute care. We present a comprehensive, pattern-based review of the CT imaging features across various forms of acute enterocolitis, highlighting diagnostic hallmarks, interpretive pitfalls, and clinically relevant mimics. The included cases were encountered by the radiologists in their day-to day practice and included based on their ability to highlight the majority representative features of each pathology. Through the integration of structured tables, illustrative cases, and diagnostic tips, this article aims to enhance the radiologist's ability to recognize key imaging signatures, avoid diagnostic errors, and contribute meaningfully to multidisciplinary patient care.