Reducing contrast material injection in elderly patients lowers cost of exam and risks

The dose of contrast material can be effectively reduced by at least 10% for elderly patients undergoing a multi-detector CT examination of the pancreas and biliary region a new study finds.

When the dose is reduced, the cost of the examination and the risk of complications is reduced. This study was conducted by the Department of Technical Radiology at Nagoya University School of Health Science in Nagoya, Japan.

"When interpreting CT images acquired using the established protocol in our clinical practice, it was noted that in some examinations of elderly patients, contrast enhancement of the pancreatic parenchyma was too intense," said Shigeki Itoh, MD, lead author of the study. "Therefore, we speculated that it might be possible to reduce the dose and rate of contrast material injection without adversely affecting the degree of contrast enhancement in elderly patients," said Dr. Itoh.

The study included 112 patients, ranging from 23-80 years old who had known or suspected pancreatobiliary disease who were split into three groups (60 years old or younger with a contrast injection of 0.08 milliliters/kg/sec, 60 years old or older with a contrast injection of 0.08 milliliters/kg/sec, and 60 years old or older with a contrast injection of 0.07 milliliters/kg/sec).

Group 3 had a 12.2% reduction in the volume and rate of contrast material injection. According to previous studies, contrast enhancement in the vessels and the organs of the abdomen increases with an increase in the volume and rate of contrast material injection. However, Dr. Itoh said that this wasn't the case in his study. Dr. Itoh noted it is essential to administer contrast material only at the volume and rate needed to achieve an adequate level of contrast enhancement for diagnosis.