New technique reduces radiation exposure by 60 percent in abdominal CT of children

By lowering the tube current to account for both the weight and body symmetry of a child, an abdominal CT radiation dose can be reduced by 60% without compromising the image quality, says a new study by researchers from the Children's Hospital of Philadelphia in Pennsylvania.

For the study, the researchers reviewed the abdominal CTs of 74 children. The researchers found that on average, modulating the tube current to account for body symmetry reduced the radiation dose by 15% over the usual weight-adjusted dose. In addition, the overall dose reduction from combining the two techniques into one ranged from 14% to 82%, depending on the weight group, for an average of 60%.

"CT is a large source of radiation exposure in medical practice for children. Although CT scans represent about 5% of all X-ray imaging, the radiation from CT is 40% to 67% of all medical radiation. By using the above technique, we can decrease the level of radiation risk to children, while still maintaining acceptable image quality. This is especially important because children have a longer lifetime in which to manifest radiation-related cancer," said Soroosh Mahboubi, MD, one of the researchers on the study.

The full results of the study were presented on May 2, 2006 during the American Roentgen Ray Society Annual Meeting in Vancouver, BC.