Acute appendicitis is a common clinical problem. Accurate and prompt diagnosis is essential to minimize morbidity. While the clinical diagnosis may be straightforward in patients who present with classic signs and symptoms, atypical presentations may result in diagnostic confusion and delay in treatment. Helical computed tomography (CT) and graded compression color Doppler ultrasonography (US) are highly accurate means of establishing the diagnosis. These imaging modalities have now assumed critical roles in the treatment of patients suspected to have appendicitis. The purpose of this article is threefold: to provide an update on new information regarding the pathophysiology, clinical diagnosis, and laparoscopic treatment of acute appendicitis; to describe the state-of-the art use of CT and US in diagnosing this disease entity; and to address the role of medical imaging in this patient population.

CT is more accurate than US in diagnosis of acute appendicitis.

In 19 patients with closed-loop intestinal obstruction, including 16 patients with strangulating obstruction, the findings at examination with computed tomography (CT) were retrospectively correlated with the surgical and pathologic findings and evaluated by two radiologists. Signs of closed-loop obstruction, present in 15 patients, were associated with the configuration of the incarcerated loop of small bowel, abnormalities detected at the site of obstruction, or both. These abnormalities were the following: a U-shaped, distended, fluid-filled bowel loop; the whirl sign; the beak sign; a triangular loop; two adjacent collapsed loops of bowel at the site of obstruction; or all of these. CT signs of strangulation, seen in 10 of the 16 patients with ischemic or infarcted bowel, were associated with the appearance of the bowel wall (thickening, high attenuation, and the target sign), abnormalities in the attached mesentery, or both. In mechanical obstruction of the small bowel, detection of ischemic changes in the bowel wall or mesentery with CT indicates strangulation. Absence of CT findings of ischemia or infarction does not rule out strangulation.

http://radiology.rsnajnls.org/cgi/content/full/242/1/109/DC1