Dual-energy head CT reduces radiation, maintains image quality for pediatric patients

Pediatric imaging centers switching from standard head CT protocols to dual-energy CT can expect such improvements as fewer artifacts, lower radiation doses, equivalent or slightly improved image noise and no significant difference in signal-to-noise ratio. In fact, the only significant downside to watch out for is longer scan times.

That’s according to the authors of a study published online in Clinical Imaging

Jason Weinman, MD, of Children’s Hospital Colorado and colleagues retrospectively compared the two CT techniques as applied to scans for visualizing regions of interest in 11 areas of the brain in 75 patients.

In CT imaging, the dual-energy approach allows the technologist to obtain two sets of image data in each slice—one at lower energy, such as 60 or 80 keV, the other at higher energy, such as 120 or 140 keV.

The gains the Colorado team observed post-upgrade were particularly pronounced in exams of children who’d passed their sixth birthday. In these dual-energy scans, there was significantly less noise in images of the infratentorial region (which contains the cerebellum), significantly improved sharpness in images of the supratentorial region (which contains the cerebrum), and overall boosts in diagnostic acceptability.

The authors also found the dual-energy protocol yielded slightly lower contrast-to-noise ratio for children over six and closely similar image quality in patients younger than 6.

Meanwhile, radiation exposure was modestly lower with the dual-energy protocol in all study populations.

“An important disadvantage to the dual-energy protocol is that the scans take longer to acquire, approximately 8.4 seconds versus 4.7 seconds for the conventional protocol,” Weinman et al. wrote. “While this has the potential to lead to more failed or repeated exams, we have not experienced this subjectively.”

The team further reported that, in the wake of this study and the stated preferences of their institution’s radiologists, their department is obtaining dual-energy scans on all head CTs performed on their dual-energy scanner. They’ve also added virtual non-contrast reconstructions to head CTs performed with contrast.

“Dual-energy CT can be used clinically in pediatric patients to maintain or improve image quality while reducing radiation dose,” the authors concluded.