ACR Appropriateness Criteria ® Acute Nonlocalized Abdominal Pain.

The range of pathology in adults that can produce abdominal pain is broad and necessitates an imaging approach to evaluate many different organ systems. Although localizing pain prompts directed imaging/management, clinical presentations may vary and result in nonlocalized symptoms. This review focuses on imaging the adult population with nonlocalized abdominal pain, including patients with fever, recent abdominal surgery, or neutropenia. Imaging of the entire abdomen and pelvis to evaluate for infectious or inflammatory processes of the abdominal viscera and solid organs, abdominal and pelvic neoplasms, and screen for ischemic or vascular etiologies is essential for prompt diagnosis and treatment. Often the first-line modality, CT quickly evaluates the abdomen/pelvis, providing for accurate diagnoses and management of patients with abdominal pain. Ultrasound and tailored MRI protocols may be useful as first-line imaging studies, especially in pregnant patients. In the postoperative abdomen, fluoroscopy may help detect anastomotic leaks/abscesses. While often performed, abdominal radiographs may not alter management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.