Ultrasound is as effective in diagnosing appendicitis as a traditional CT scan, providing doctors with a possible new way to identify the condition without posing patients to radiation risks, new research shows.
The study, by medical specialists from the Washington University School of Medicine in St. Louis, compared the effectiveness of CT scans, which involve radiation, with ultrasound scans, which use sound waves instead of radiation to confirm or rule out the need for surgery to remove the appendix.
The results showed that children suspected of having appendicitis are more likely to receive CT scans, if they are evaluated at a general hospital. But patients who went to St. Louis Children's Hospital were more often evaluated with an ultrasound scan — a technique that is safer, but equally effective.
Both techniques were found to reduce the risk of unnecessary surgeries. But researchers noted the radiation exposures in CT scans can significantly increase a patient’s lifetime cancer risk, particularly in children.
"Appendicitis is a very tough diagnosis, because its symptoms overlap with viral infections and other problems," said Jacqueline Saito, M.D., an assistant professor of surgery who helped conduct the study, published in the journal Pediatrics. "We don't want to operate when the appendix is fine, but if we wait too long, an inflamed appendix can rupture or perforate, making recovery more complicated and much slower."
The appendix is a finger-shaped organ that extends from the large intestine. Infection or blockage of the appendix causes appendicitis, which can lead to abdominal pain, vomiting, and fever. For many years, CT scans, which take X-ray images from multiple angles, have been used to detect appendicitis and indicate the need for an appendectomy — surgery to remove the appendix.
For the new study, Saito and her colleagues analyzed medical charts of 423 children who had appendectomies at St. Louis Children's Hospital. About half were initially evaluated at Children's Hospital and the others at general hospitals.
The results showed about 85 percent of the patients initially evaluated at a general hospital underwent CT scans. But more than half of those evaluated at St. Louis Children's Hospital had preoperative ultrasound instead and were accurately diagnosed at a rate comparable to those who received CT scans.
"Ultimately what we'd like to do is learn how we can reduce our use of CT imaging without compromising patient care," Saito said. "We want to find ways to identify the patients who really need these scans and those who can be effectively evaluated using other methods."