Northwest Health Summer 2011

Patient Safety

Taking a Closer Look at CT Scans

CT scans are helpful when it comes to diagnosing a disease or condition, but they are not without risks.

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The CT or CAT scan — shorthand for X-ray computed tomography — is a powerful diagnostic tool that gives physicians two-dimensional images of internal organs, bones, and soft tissue. It detects many abnormalities or injuries not seen in a typical X-ray.

Despite its benefits, the CT scan has come under scrutiny because of a dramatic increase in its use. Nationwide, the use of CT scans increased by 115 percent between 1998 and 2005, according to an analysis by the American College of Radiology.

While some individual patients have benefited, there is no clear evidence that the higher usage has resulted in better care for all patients. A CT scan delivers a big dose of radiation which has caused a small increase in cancer risk for patients. And they're expensive, contributing to higher health care costs.

Is a scan really necessary? The increase in CT scans across the country comes down to an over-reliance on technology over other equally effective diagnostic methods, says Matt Handley, MD, Group Health associate medical director of quality and informatics.

"Physicians are looking for the diagnostic certainty that one test can deliver," says Dr. Handley. But often, taking a thorough health history and carefully examining the patient will lead to a diagnosis with no need for a scan. Other times, another test with fewer risks and a lower cost, such as an ultrasound, may yield equally informative results.

Several years ago, when physicians at Group Health looked at reports that indicated a significant upswing in CT scan use, they began to consider how to decrease use while maintaining high-quality patient care, says Dr. Handley. Their first step was adding a series of questions to Group Health Medical Centers' electronic medical record system. These questions help physicians assess whether a CT scan is the best way to diagnose a patient's condition. If they're still uncertain that a scan is needed, physicians are encouraged to consult a radiologist.

"We can send a quick message to a radiologist to review the clinical case and make a recommendation on what's best for the patient," says Dr. Handley.

Safer scans. When a CT scan is important for a diagnosis, Group Health Medical Centers is investing in training and equipment that reduces a patient's radiation exposure, says Carl Mayberry, a district manager for radiology services. Technologists and radiologists work together to make sure the smallest area possible is scanned, and that each scan is tailored to the person's body type.

Manufacturers are also developing new ways to reduce radiation from CT scans without compromising quality. Software for new and older CT scanners is reducing the amount of radiation by 60 percent to 80 percent, says Mayberry.

How to protect yourself. The best thing patients can do if their doctor orders a CT scan is to ask this question, says Dr. Handley: How will the test results change my care? "Often, people assume that establishing a diagnosis will lead to an improvement in care. That's not always the case. If it won't change the decision about care, the test may not be important.

"The only reason to do a CT scan is if the benefits of doing it outweigh the risks. The only way to determine that is to have a conversation with your doctor based on your symptoms and your health history."

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