Recently, NPR ran a story about the increasing use of Computerized Tomography (CT) scans in Emergency Departments (EDs) across the United States. CT scans are powerful X-ray machines that allow physicians to quickly and accurately diagnose a wide range of conditions. They are different than normal X-rays because they produce a three-dimensional image. Plain X-rays are two-dimensional. For many conditions, the added information that the three-dimensional image adds makes it much more useful than plain X-rays.
NPR reports that CT scan use in EDs has increased six-fold nationally since 1995. There are a number of reasons for this. First, CT scans have improved greatly in the past two decades. The images that we now obtain are truly amazing and allow physicians to see and diagnose many conditions that previous scanners were unable to visualize. Conditions such as appendicitis, pulmonary embolism (blood clot in the lung) and even heart disease are now easily diagnosed by CT scan. None of this was possible with older scanners. As scanners have improved and become more available, doctors have become more comfortable ordering scans to quickly make decisions that may have been very difficult prior to CT scans. Some conditions such as bleeding around the brain are quickly diagnosed with a CT scan. Before CT scans, this often required an operation to see if there was bleeding.
It should be noted that according to the Dartmouth Atlas, Vermont currently has the lowest CT use in the United States, with a utilization rate that is 40% of the national average. The UVM Medical Center accounts for more than half of the radiology studies in the state.
The accuracy and value of CT scans comes with some considerations. The high resolution images that are so useful require a significant dose of radiation to the patient. Some research has suggested that a single abdominal CT scan increases your lifetime risk of cancer by 1%; however, the latest research shows this percentage is most likely overstated for middle aged adults, and very likely an over-estimation for older adults. For many conditions that need to be diagnosed quickly, the risk is clearly worth it and the scan is necessary and appropriate. For other problems, your provider needs to weigh the risk of radiation exposure against how quickly the diagnosis needs to be made.
At the UVM Medical Center we are very aware of the benefits of CT scans and the concerns of radiation exposure. We balance these issues every time we consider ordering a CT scan. CT scans are used in our ED every day to diagnose a wide variety of life threatening conditions. In many situations we elect not to get a CT scan to prevent the radiation exposure to the patient. In fact, we have adopted a policy at the UVM Medical Center called “Image Gently.” This policy pledges to use the least radiation possible to make an accurate and timely diagnosis. We have just installed iDose software on the 128 slice iCT, which maintains image quality while reducing radiation exposure, and CT dose reduction of up to 50% is now used on our scanner in the Ambulatory Care Center.
We are constantly looking for ways to make scans more accurate while using less radiation. Based on research currently under way, we expect CT dose reduction of greater than 95% to be available in the next several years. Also, other technologies like MRI are being used more. MRI’s have no radiation exposure but are not yet accurate enough to replace CT’s for many problems. It is quite likely that over the next 25 years, MRI and other new exciting technologies will improve our ability to quickly diagnose patients’ problems with less radiation than we need to use now. Be assured that we will adopt new technologies as they develop and are proven safe and useful.
For now, if you need to visit an ED, be prepared to discuss the value and usefulness of a CT scan with your provider. With your provider’s input and expertise you can make an informed decision about the care strategy that is best for you.
Stephen M. Leffler, MD, is Medical Director of the UVM Medical Center’s Emergency Department.