Image-Processing Algorithm Reduces CT Radiation Dose By As Much As 95 Percent
Perfusion CT scanning, an emerging imaging technology, got a bad rap last year when a machine set to incorrect radiation levels overdosed hundreds of people in Los Angeles. In the wake of this incident, researchers at the Mayo Clinic, excited by the technology's promise for diagnosing stroke, cancer, and possibly heart disease, have developed a way to reduce the amount of radiation involved in the procedure - which, when done properly, already involves very little risk.
"At the correct dose, there should be no injury," said Cynthia McCollough. "We believe in the clinical value of perfusion CT, so we're trying to lower the dose and reduce the stigma."
McCollough and her colleagues created a new image-processing algorithm that can give radiologists all of the information they need using as up to 20 times less radiation, depending on the diagnostic application. The research was presented at the 52nd Annual Meeting of the American Association of Physicists in Medicine (AAPM) in Philadelphia.
A typical CT perfusion procedure lasts about half a minute and scans the same tissue many times, each scan at a low dose. These scans both reveal the internal anatomy of the patient and show how levels of a contrast agent, such as iodine injected into the bloodstream, change of over time. Changing concentrations of iodine can be used to calculate blood volume and flow in order to detect injuries to blood vessels or tumor responses to treatment.