On CT Scans

A recent set of articles on the June issue of NEJM address the issue of CT scans, NEJM — Is Computed Tomography Safe? and NEJM — The Uncritical Use of High-Tech Medical Imaging. The emergency department is one of the biggest culprits – over the last decade, CT scans have become the imaging modality of choice. It has become part of the package ED patients receive: name band, urine sample, ekg, a listen to the lungs, and a CT scan before you go on your way – just to make sure we’re not missing anything. Although the definitive risks vs. benefits of CT scans have not been studied thoroughly (the long-term effects will need to be examined in the coming decades), the cancer risk from abdominal and chest CT scans is indubitably substantial.

The CT scan is the modality of choice for patients with traumatic injuries, head injuries, and abdominal pain. It serves as a definitive screen for a myriad of medical conditions which may or may not be picked up by other imaging modalities: cholecystitis, appendicitis, small bowel obstruction, and the list goes on. But just like anything else in medicine, the benefits of the test are accompanied by substantial risks – in this case, the risk of malignancy, which may be as high as 1 percent for a single scan.

The importance of discussion around CT scans will be important in the coming years, especially in the emergency department, where time is of the essence and patients can be whisked away to the donut hole without a sense of what the consequences may be. One of the major tenets of the Hippocratic oath is First, do no harm. With the advent of new machines, imaging modalities, and medical technology, we must realize as physicians that we still have the same responsibility with these tools as we do in the operating room or in our office. The goal for the near future is to reduce use of CT scans in the ED and to transition to alternative, less radiating modalities such as MRI and ultrasound when possible.