By Deborah R. Dakins

Power Doppler ultrasound is a valuable, cost-effective tool in assessing risk of stroke in patients with sickle cell anemia, offering a highly visual way to evaluate blood flow and arteries, according to research presented at the RSNA meeting on Tuesday.

Previous studies have shown that use of pulsed Doppler is valuable in detecting abnormal blood flow in children with sickle cell disease. Those with the most abnormal blood flows, characterized as 200 cm per second or higher, carry a 40% risk of stroke. Once those patients are identified, monthly blood transfusions can decrease that risk by 90%. But because the transfusions themselves can cause complications in young patients, it's important to ensure that only those at highest risk are tapped to receive them.

Power Doppler offers a higher edge of diagnostic confidence, according to Dr. Abe Malouf, an assistant professor of radiology at the University of Mississippi Medical Center, Jackson.

"Power Doppler is a quick, noninvasive test that can be easily learned," he said. "The visual nature of the images means we have something we can show clinicians that demonstrates the abnormal flow. And that's important, because they don't want to start transfusing someone they don't have to."

In 126 pediatric sickle cell patients studied to date, with follow-up ranging between six and 18 months, 10 patients exhibited abnormalities. Eight of those patients underwent a subsequent MRA study that confirmed the Power Doppler findings, and began a blood transfusion regime. Two patients suffered stroke, one of which was nonclinical.