Avoiding unnecessary CT exams, adjusting individual scanning parameters, revising protocols and educating staff were among a number of methods that radiologists at William Beaumont Hospital in Royal Oak, Mich., found effective in reducing CT radiation dose.
While CT accounts for nearly 15 percent of all imaging tests, it contributes up to 70 percent of the total radiation dose to the population, according to the authors of a recent study published in the American Journal of Roentgenology. The increased scrutiny over the growing amount of radiation exposure has prompted efforts to reduce dose.
In March 2010, a committee was formed at William Beaumont to address radiation dose at the institution. Composed of four radiologists, two physicists, a radiation safety officer, two CT technologist supervisors and others, they formulated a plan that included avoiding unnecessary procedures, adjusting parameters, targeting organ-sensitive dose reduction and quality control.
“The most effective way to reduce radiation dose attributed to CT is by reducing the number of CT examinations performed unnecessarily,” wrote Elias J. Antypas, MD, PhD, and colleagues from the department of diagnostic radiology at William Beaumont. “Many CT examinations are performed annually for many reasons that are unwarranted.” For example, authors noted research that reports 30 percent of all CT examinations in children are needless, and many exams are duplicate studies.
To reduce repeat CT exams within the hospital, a CT log book was placed at each scanner to record the number of repeat exams ordered within 24 hours of each other. Data were collected for repeat studies and new policies and modified low-dose protocols were established as a result. Some revised policies included review and approval for new CT exams and automatic alerts to physicians and technologists of repeats.
The committee also made efforts to minimize scanning length to only areas of interest, and in targeting organ-sensitive dose reduction, used shielding to limit radiation exposure. The use of a thyroid shield was implemented for all patients undergoing chest CT exams as well.
“To ensure the proper implementation of procedures and new protocols, multiple inservice lectures were given to CT technologists by radiologists and physicists,” wrote Antypas et al. "This was done to outline the previously discussed approach to radiation dose reduction without compromise to image quality.”
Additionally, monthly quality control conferences were held and a call center was established to answer questions from physicians, patients and the public regarding radiation dose.
“CT is a valuable diagnostic tool that has achieved widespread use because of the benefits provided for patient care,” the authors wrote. “However, with its increased use, CT accounts for a significant portion of the total population radiation dose, which has led to increasing scrutiny. At our institution, using a team approach, we have put in place a culture that is attentive and responsive to patient radiation exposure and have established a means to address this based on the avoidance of unnecessary CT examinations, adjustment of scanning parameters, revision of protocols and education of CT technologists and physicians.”