Researchers work toward safer imaging for obese patients

Obese patients get higher doses of radiation during CT scans than other patients, but that's difficult to quantify, since there's currently no computational human phantom--models that allow radiation dose to be assessed--for obese patients. Part of the reason is that as body weight increases, it's harder to get a quality image of organs, requiring greater radiation doses.

However, optimizing procedures can produce medical images that are both safe and effective, according to a new study in the journal Physics in Medicine & Biology.

Researchers developed a set of ten computational phantoms representing five male and five female patients of body mass index (BMI) classifications ranging from normal to morbidly obese. X-ray computed tomography (CT) scans are simulated on each of the phantoms to study the effect of obesity on CT imaging dose.

"This set of new obese phantoms can be used in the future to study the optimization of image quality and radiation dose for patients of different weight classifications. Our ultimate goal is to compile all the data derived from these phantoms into a comprehensive dosimetry database," the researchers wrote.

"As medicine is trending towards more patient-specific approaches, these phantoms are expected to be useful in future studies aimed at optimizing CT image quality while appropriately managing the patient radiation exposure."

A software package called VirtualDose will contain a comprehensive database of data on normal-sized, obese and child patients. It is slated to undergo clinical testing this summer, according to HealthImaging.

Diagnostic imaging procedures should be conducted at the lowest radiation dose to make a diagnosis, the American Association of Physicists in Medicine (AAPM) has said. But some experts say fears of radiation exposure in the healthcare setting are overblown--even sensationalized.

Radiation exposure made ECRI Institute's list of top 10 healthcare technology hazards for 2012. Both the The Joint Commission and the Centers for Medicare & Medicaid Services also have weighed in on the issue of overuse of radiation testing.

To learn more: 
- check out the Physics in Medicine & Biology research report
- read the HealthImaging article