Medical professionals meet to standardize CT scanning techniques

Imaging experts met in Atlanta last month to standardize CT scanning techniques

A national summit of medical professionals meeting last month in Atlanta called for the creation of consensus scan techniques as a way of addressing the concerns of patients undergoing CT scans -- a common medical imaging procedure that uses X-rays to show cross-sectional images of the body.

The summit brought together some of the world's leading experts in CT imaging, including medical physicists, radiologists, technologists, and equipment manufacturers. It was hosted by the American Association of Physicists in Medicine (AAPM), a professional organization whose members include board-certified health professionals and research scientists specializing in the use of radiation in medicine.

According to Cynthia McCollough, Ph.D., Professor of Radiologic Physics at the Mayo Clinic, who co-organized the meeting on behalf of AAPM, the summit achieved its goal of identifying several issues that need to be dealt with by the medical imaging community in order to address the safety concerns of patients at U.S. hospitals and clinics.

In the last several months, many medical physicists have witnessed first-hand how some patients have grown concerned about stories in the media questioning the risks and challenging the safety of CT scans.

"We all hear it every day. Patients ask, 'do I really need to have this procedure?'," said Dianna Cody, Ph.D., another co-organizer of the meeting. Cody, who is Professor of Imaging Physics at the University of Texas M. D. Anderson Cancer Center, says that patients should not be afraid of getting medically appropriate CT exams. "When medically justified," she said, "the benefits of CT scans far outweigh the risks."

Even so, patients' fears are very real. The CT Dose Summit arose partly as a response to these fears, as leaders within the AAPM CT community discussed what more professionals in their field could do to ensure patient safety and to reassure patients coming for CT.

These discussions led directly to the summit, one outcome of which was a call for imaging professionals and equipment manufacturers to precisely define and use a consistent set of terminology to eliminate ambiguity when staff move between different types of scanners or when technical issues are discussed with staff who have different backgrounds.

The summit also made the case for developing consensus CT protocols and making them freely available via the Internet to hospitals and clinics across the United States. CT protocols -- or scan instructions -- identify the equipment settings and define starting points for a given procedure. Because protocols determine the quality of a CT exam and the amount of radiation used, they must be optimized to deliver the quality needed to make a confident diagnosis and to keep the doses as low as reasonably achievable.

Up to now, hospitals and imaging centers have developed their own protocols, typically based on recommendations from the manufacturer. However, many in the field have pointed out that with the increased capabilities and complexities of modern CT systems, it does not make sense for each institution to develop its own protocols.

AAPM has long led efforts to support the use of standards for measuring and minimizing radiation dose in medical applications, including CT procedures. Hospitals and clinics employ AAPM members to review CT protocols and check the proper functioning of scanners. Organizing the summit was a logical extension of this work.

"We were responding to what we heard from many professionals, calling for consensus protocols that would improve and standardize image quality and reduce radiation dose," said McCollough, who is a medical physicist and director of Mayo Clinic's CT Clinical Innovation Center in Rochester, MN. "In Atlanta, we laid the groundwork for medical professionals, manufacturers who make and market medical scanners, and government regulators to work together to develop these protocols."

"This effort will go a long way toward addressing patient safety concerns and ensuring that CT exams are performed as safely and effectively as possible," said William Hendee, PhD, the third co-organizer of the meeting. Hendee is Chair of AAPM's Technology Assessment Initiative and a professor at the Medical College of Wisconsin, Marquette University, and the University of Wisconsin - Milwaukee.

At the summit, speakers reviewed the fundamental principles of protocol design and examined several protocols developed at some of the nation's largest and most prestigious hospitals. These protocols cover the most common types of CT exams, from routine imaging of the head and body, to newer applications such as cardiac CT and CT perfusion imaging.

The AAPM started its protocol optimization with CT perfusion, the highest-dose CT procedure. Their consensus guidelines will soon be publicly available to help practices nationwide make sure they are performing this examination correctly.

"This provides us with strategies on how to reduce overall dose to patients," said Bob Turco of West County Radiology Group in St. Louis, MO.