Advertisement
Improving CT Safety

Improving CT Safety

CT is a powerful diagnostic technology, but it is also associated with risks. Ionizing radiation can damage cells and act as a weak carcinogen. The challenge is to find the optimal x-ray dose for each CT exam. “About 80 million CTs are performed each year in the United States,” says John M. Boone, PhD. “The higher the dose, the better the images, but we also want the lowest possible dose so that patients are protected from unnecessary radiation exposure. The key is to find the balance between acceptable image quality and acceptable doses.” New Strategies The Journal of the American College of Radiology (JACR) recently devoted an entire issue to CT safety. Dr. Boone and other specialists from the University of California, Davis contributed three studies to the special issue. In one of the JACR papers, the need to improve dose calculations was discussed. Manufacturers use phantoms along with instruments to measure radiation, but different companies use phantoms of different sizes, making comparisons problematic in some cases. To prevent these problems, a new metric, the size-specific dose estimate (SSDE), is recommended. “SSDEs can provide a better way to estimate patient doses and can help compare scanners from different companies,” says Dr. Boone. SSDEs may also address the need to more accurately estimate CT doses from a range of patient sizes, especially in pediatric patients. The second JACR paper addressed the challenges of optimizing different CT machines. Automatic exposure protocols must be set up, but this can vary doses based on tissue thickness. “Transferring these settings between machines can be difficult and time consuming,” Dr. Boone says. To overcome this...
[ HIDE/SHOW ]