It’s one of the primary goals at the heart of patient safety in radiology: balancing the need for heightened image quality with the inherent risks of radiation exposure.
It’s also a goal that prompted researchers from the University of Massachusetts Medical School to develop some simple yet creative radiation-dose solutions, according to an article published online Jan. 20 in the Journal of the American College of Radiology.
“Larger doses result in higher quality images,” wrote lead author Byron Chen, MD, and colleagues. “The goal then is to strike a balance to maximize patient safety: reduce radiation without compromising the quality of the image.”
When Chen and his team discovered that the typical dose rate for lumbar spine CT at their Memorial Campus facility—15.5 mSv over a five-month span—was more than 50 percent higher than a typical CT scan of the lumbar spine, they knew there was a problem with the process. Seventeen cases involving larger patients were also found to have exceeded 25 mSv, considered by the researchers to be an extraordinarily high dose.
To better understand what was causing this increase in radiation exposure, Chen and his colleagues performed a root-cause analysis and determined that the issue was largely linked to personnel and protocol.
“This problem was due to technologists failing to properly set a maximum radiation dose,” the researchers wrote. “It was further determined that the issue resulted from a lack of a specific protocol and proper training that would have allowed the technologists to better use the limitation of maximum dose.”
Chen and his team implemented two major countermeasures to fix the problem. First, they formalized personnel training for lumbar spine CT protocols, including the addition of a note for radiation limitation into the standard work protocol binder as well as specific instructions for technologists to set a maximum radiation dose prior to performing a scan.
Their second countermeasure consisted of the completion of a standard radiologist survey evaluating imaging quality following radiation dose limitation. Polling of fellowship-trained musculoskeletal radiologists before and after implementing the countermeasures was conducted to determine their effectiveness.
Their results showed that establishing a specific protocol and technologist training regimen resulted in a 19 percent reduction in average dose, from 15.5 to 12.5 mSv, in the two months after implementation. Additionally, the number of cases involving doses higher than 25 mSv was reduced to zero for the month directly following deployment of the countermeasures.
That’s a big improvement, said Chen and his colleagues, and a result that should spur other providers to reexamine their own protocols and technologist training regimens.
“Given the findings of our study, similar systems involving specific protocol reconfiguration and proper technologist training on the use of maximum dose in (automatic exposure control) systems should be applied to other CT scanner locations and examinations performed,” the researchers concluded.