In 1888, William Osler wrote in the Lancet the following: "In patients with suspected acute appendicitis, one should urge towards laparotomy. The indications for surgical interference are not always clear, but in my experience I have been taught that the abdomen is much more frequently left untouched than it should be, and that an operation is too often deferred until practically useless." Clearly, diagnosis of acute appendicitis has come a long way since then. But challenges remain in selecting the safest, most timely, and cost-effective diagnostic modalities for this condition. Dr. Andrea Doria, associate professor in the department of medical imaging at the University of Toronto School of Medicine, clarifies the use of ultrasound versus CT for evaluation of acute appendicitis in children. Dr. Jason Birnholz hosts.