May 2013

 

Dr. Steven Don   Washington University School of Medicine, St. Louis Children's Hospital

Up-Close and Candid Dr. Steven Don is an associate professor of radiology at the Mallinckrodt Institute of Radiology, Washington University School of Medicine, and specializes in pediatric radiology at St. Louis Children's Hospital. He received his medical degree from Vanderbilt University in 1985 and completed a pediatrics internship at the University of Minnesota, a radiology residency at Indiana University, and a fellowship in pediatric radiology at James Whitcomb Riley Children's Hospital in Indianapolis. He won the Caffey Research Award for Best Scientific Paper in 2008 from the Society for Pediatric Radiology; the paper was based on a quality assurance phantom he developed from NIH STTR grants. In 2011 he was part of the Pediatric Dose Reduction Group effort of Image Gently that received an FDA Leveraging/Collaboration Award for developing a network aimed at reducing unnecessary radiation exposure to pediatric patients from imaging exams.

"Nationally, 74 % of the exams radiologists interpret are x-rays....While [they] may not have the sex appeal of the MRI or CT, we need to make sure we do the basics right." -S. Don

How do we best safeguard children from the over-radiation that medical imaging procedures deliver?

In an interview with AJR InBrief, Dr. Steven Don, corresponding author of the review article "Image Gently Campaign Back to Basics Initiative: Ten Steps to Help Maintain Radiation Dose in Pediatric Digital Radiography" in May's AJR Online, tells us why he's so passionate about low-dose for kids and why you should be, too.

Here's what he had to say:

Q: Radiology exposure has been a hot topic in medicine for years. What specifically draws you to this subject?
A: When I was a resident in the 1980s, we obtained radiographs using screen-film cassettes. Towards the end of my residency, I started using computed radiography at Riley Children's Hospital; I was fascinated with the use of computers and saw the potential for image distribution. Even though computed radiography was reported as dose savings, I saw the exposure factors rising. Exposure creep was a problem mainly due to the issue of noise. Some attending radiologists would be worried about missing disease processes because of the noise. I became interested in studying the relationship among noise, diagnosis, patient exposure, and quality assurance.

Q: Was there a particular medical case that made you take notice?
A: There was no specific case. But I've been interested in radiology exposure research since my residency, when every day I saw some neonates getting multiple x-rays. I thought if we could lower the dose yet provide the information the clinicians needed, such as endotracheal tube position, it would be in that neonate's best interest.

Q: You refer to exposure creep in patients. Is there a tell-tale sign that a child has been overexposed?
A: No, and that is the potential problem. As with CT, overexposed images appear ideal without any noise in the image, whereas underexposed images are recognized by radiologists and radiographers as grainy or noisy. We prefer to interpret ideal, noise-free images. And over time, there is a tendency to raise the exposure factors to create the perfect image. I want an acceptable image, not a perfect one. The best way to avoid overexposure is to monitor the exposure indicators to check that they are within an acceptable range.

Q: Why the Image Gently campaign? Aren't there other low-dose initiatives out there for pediatrics?
A: There are other initiatives, such as the Image Wisely and Choosing Wisely campaigns, but they focus on adults. Image Gently (part of the Alliance for Radiation Safety in Pediatric Imaging) was the first initiative and focuses on children. It has had five educational campaigns and two summits. The second summit focused on digital radiography and helped forge an agreement between the imaging community and vendors to adopt the International Electrotechnical Commission exposure standards for reporting exam exposure (Step 3 of 10 outlined in Dr. Don's article).

Q: Of the 10 steps you outline in your article to best manage radiation exposure in pediatrics, which is the most important?
A: I think each step is important, but the most important step(s) depends on the physician's experience with digital radiology. I like to group the steps. The first three steps are knowledge basics, the next four steps deal with setting up and optimizing imaging of a particular patient, and the final three steps are quality assurance.

Q: Which is the most challenging?
A: I think the most challenging aspect is getting some departments to measure body-part thickness instead of using patient age as the primary technique determinant. The measuring-thickness technique was first used years ago with film-screen radiology. With digital radiography, many centers began using patient age. We need to go back to measuring thickness because there's a difference in techniques between a rail-thin, 5-year old and an overweight 5-year-old. One size does not fit all! We need to measure each patient and adjust the technique to suit that patient. In this sense, the old way is better. In fact, one hospital that decided to switch back to measuring thickness reported that they had to go and purchase calipers. So this will change the department workflow but should improve overall image quality. By following the imaging steps, using a technique chart, and developing a quality assurance program, exposures can be monitored to avoid exposure creep.

Q: What about patients with childhood conditions, such as scoliosis, who need several radiography treatments before age 18? How can Image Gently make a difference with them?
A: I would encourage the parent of any child undergoing a medical test to talk with the ordering physician to make sure that the test is medically indicated. When in the radiology department, the parents should ask the radiologic technologist if the study will be appropriately "child-sized" for their child.

Image Gently provides valuable educational materials geared separately to the parent, radiologic technologist, medical physicist, radiologist, and referring physician. So, everyone involved—from the patient to the medical team—has information that speaks directly to him/her.

Q: How should your colleagues promote low-dose radiology in their facility?
A: Radiology exposure first became a hot topic with the February 2001 AJR issue and still is. Like I mentioned in #6, Image Gently is a great resource. Its Digital Radiography Back to Basics campaign has five PPT presentations, two papers, and the talks at the CR/DR summit in February 2010. Plus, there is a section on quality improvement containing a "do and verify" safety checklist developed in conjunction with the FDA, and a Practice Quality Improvement project for the radiology department.

Q: Last thoughts?
A: Nationally, 74% of the exams radiologists interpret are x-rays; we read a lot of radiographs every day. While it may not have the sex appeal of the MRI or CT, we need to make sure we do the basics right.

For more information on radiology exposure or the Image Gently campaign, read Dr. Steven Don's review article, "Image Gently Campaign Back to Basics Initiative: Ten Steps to Help Manage Radiation Dose in Pediatric Digital Radiography," in May's AJR Online.