A study published in the October 2011 issue of the American Journal of Roentgenology, states that the radiation dose for a CT fluoroscopy is about half that for conventional fluoroscopy to guide epidural steroid injections. However, the dose is substantially more than conventional fluoroscopy when a full lumbar planning CT scan is performed as part of the CT-guided procedure, the new study shows.
Physicians may hesitate to use CT fluoroscopy because of concerns about radiation dose, said Jenny K. Hoang, MD, of Duke University Medical Center, and one of the authors of the study. However, the study found that since CT fluoroscopy itself takes less time than conventional fluoroscopy (4.7 seconds versus 37 seconds on average), the radiation dose is actually much lower. The study found that absorbed radiation dose to the skin, small bowel, large bowel, and bone marrow was greater for conventional fluoroscopy compared with CT fluoroscopy. However, when you combine the dose of the planning CT (scan range from L2 to S1) with that of the CT fluoroscopy itself, the dose is four times higher compared to conventional fluoroscopy.
Hoang emphasized that the study results are based on the protocols they use at her institution. “Radiation dose values are highly dependent on the fluoroscopy time used by the individual doing the procedure and the dose settings that are used at his or her institution,” she said.
