Why a pediatric radiology department made the move to dual-energy head CT scanning

When imaging pediatric patients, dual-energy head CT decreased radiation dosage, reduced artifacts and maintained a high-quality image compared to conventional head CT protocols, reported authors of a Feb. 7 study published in Clinical Imaging.

“Given the results of this study and radiologist preference, our department now utilizes dual energy scans on all head CTs performed on our dual energy scanner,” wrote first author Jason P. Weinman, MD, with the department of radiology at Children’s Hospital Colorado in Aurora, and colleagues.

Weinman et al. retrospectively compared both CT techniques, which were utilized to visualize regions of interest in 11 areas of the brain in 75 patients.

Overall, the dual-energy protocol modestly lowered radiation exposure in all populations. And in children older than six years, dual-energy CT resulted in significantly less noise in the infratentorial region of the brain, and significantly improved sharpness in image quality of the supratentorial region, with overall increases in diagnostic acceptability.

The group also determined the dual-energy technique resulted in lower contrast-to-noise ratio in pediatric patients over six and similar image quality in those younger than six.

Why did the dual-energy protocol result in improved performance? The protocol, which only allows the use of 40 detectors instead of the 128 in conventional scans, is likely a large factor.

“This use of a narrower band of detectors for the (dual-energy) DE protocol may account for some of the improvement in image quality,” the authors wrote. “This also explains why there is a greater reduction in radiation exposure, as the difference is likely due to over ranging with the wider detector field in the conventional scan.”

The only real disadvantage to the dual-energy technique, according to the authors, is that scans will take approximately 8.4 seconds, compared to the 4.7 seconds for traditional CTs. This could lead to more failed or repeated exams, but has not happened at the Colorado institution, Weinman and colleagues noted.