ACR, ASNR call for CT scan, dosage protocols
The American College of Radiology (ACR) and American Society of Neuroradiology (ASNR) have released a joint statement calling for an established set of CT scan and radiation dosage protocols, following the FDA’s notification of a safety investigation of CT brain perfusion scans earlier this month after a radiation overexposure at Cedars-Sinai Medical Center in Los Angeles.

“It is likely that the recent incident of radiation overexposure from CT will promote more attention and resources to be allocated to appropriate CT protocol design,” read the ACR/ASNR statement.

“Ideally,” the organizations said, “each CT scan protocol would be designed to just meet the image quality need for the examination to be conducted on each patient, using the appropriate dose level.”  ACR and ASNR suggested employing a hydra-headed team of the lead radiologist, lead CT technologist and a qualified medical physicist to design and review all new or modified protocol settings, as well as a regular review process on recurring protocols.

The process for establishing a protocol has been difficult, the organizations said, pointing out that various CT scanner manufacturers have adopted slightly different implementations. As a general guideline, the Reston, Va.-based ACR has established dose reference levels for three common CT exams: adult head (75 mGy), adult abdomen (25 mGy) and pediatric abdomen (20 mGy).

Less common exams prove to be a more difficult task, and the organizations gave additional suggestions on how to minimize patient dose in CT:
  • Develop internal radiation dose thresholds during any new CT protocol design.
  • If an estimated dose value is above the applicable threshold for any routine clinical CT exam, implement steps to ensure patient safety and reduce future risk.
  • Do not disable the CT dose estimate interface option; be sure that the dose information is displayed during the exam prescription phase.
  • CT staff should maintain CT-specific continuing education that focuses on patient safety.
  • Obtain ACR CT Accreditation for an independent check of a facility’s personnel, imaging techniques, image quality and dose.