Report from ARRS: Benefits of abdominal CT in the emergency room outweigh radiation risks

April 16, 2008

Radiation protection watchdogs have raised the alarm over increasing utilization of CT, particularly in the emergency room. But a prospective study from Harvard University so far shows that CT’s benefits may outweigh the risks, at least for triaging abdominal pain.

Radiation protection watchdogs have raised the alarm over increasing utilization of CT, particularly in the emergency room. But a prospective study from Harvard University so far shows that CT's benefits may outweigh the risks, at least for triaging abdominal pain. Abdominal CT could help emergency department physicians attain a high level of diagnostic confidence while securing a faster workflow, according to Dr. Rathachai Kaewlai, a radiologist at Massachusetts General Hospital. Trial results were presented Tuesday at the 2008 American Roentgen Ray Society meeting in Washington, DC.Kaewlai and colleagues prospectively reviewed an institutional review board-approved survey that was passed among ER physicians at MGH. Physicians had to fill out the survey before and after a CT scan was performed for triage of abdominal pain. The survey included questions about the top diagnosis, the level of confidence regarding diagnosis, and the management plan.The investigators found that CT has influenced or changed management in three out of four of the 515 patients to date presenting to the ER with abdominal pain.

The survey documented the most common pre-CT diagnoses:

  • kidney stones, 17%
  • small bowel obstruction, 11%
  • diverticulitis, 10%
  • appendicitis and abscess, 8% each
  • nonacute and other conditions, about 46%

In patients with pre-CT suspected appendicitis, 15% were found to have no acute condition on post-CT. The average level of diagnostic certainty in physician top diagnosis increased from 60% (pre-CT) to 92% (post-CT). Of all cases that physicians had planned to admit before having a CT scan done, post-CT reevaluation led to patient admission in 20%, surgery in 23%, and discharge in 23%.

Abdominal CT increases ER physicians' confidence in their final diagnosis, reduces inappropriate admissions, helps lead proper admissions and avoid unsafe discharges, and serves as a guide for surgery or conservative management, Kaewlai said."Abdominal CT clearly changes the patient management and improves the quality of care in the emergency room," he said.Further studies will answer specific questions about CT's cost-benefit equation. Physicians in general may find it useful to know that when it comes to abdominal pain, CT really helps their decisions, coinvestigators attending the presentation said. For more information from the Diagnostic Imaging archives:

Emergency room CT scanning of teenagers skyrockets

Image Gently alliance seeks to cut pediatric radiation

NEJM article blames CT-related radiation up up to 2% of cancers in U.S.

Academy calls for emergency CT for some seizure patients