Ultrasound findings of acute appendicitis
- The appendix appears as a round target with an anechoic lumen, surrounded by a hypoechoic and thickened (greater than 2 mm) appendiceal wall.
- This finding with reproduction of pain under the transducer has a diagnostic accuracy of 95% and a negative predictive value of 97%.
- Although US evaluation for appendicitis has the advantage of bedside portability and lack of radiation, CT has been shown to have superior sensitivity, accuracy, and negative predictive value (96% versus 76%, 94% versus 83%, and 94% versus 76%, respectively).
