July 18, 2011

Heart Scans: Safer for Kids

(Ivanhoe Newswire) -- Coronary computed tomography angiography (CTA) is an effective way to diagnose kids with heart problems. Now, newer techniques are making CTA safer for pediatric patients.

"Traditionally, pediatric patients who require coronary artery imaging have undergone a cardiac catheterization, which is an invasive procedure with a significant radiation dose, requiring sedation or anesthesia for all patients," B. Kelly Han, M.D., a pediatric cardiologist at Minneapolis Heart Institute at Abbott Northwestern Hospital and the Children's Heart Clinic and Children's Hospitals and Clinics in Minneapolis, was quoted as saying. "The newer CT scanners deliver far less radiation than both previous generation CT scanners and catheter-based angiography. Also, CTA is non-invasive and has different protocols that can be tailored to decrease the risk for each individual patient."

The researchers say one problem with using CTA on children has been their higher heart rates. However, using a combination of medications to slow the heart rate along with the new scanner technology, doctors have been able to obtain clear images of the coronary arteries in children as young as 5 months of age.

Researchers conducted a review of all coronary CTAs performed on patients less than 18 years of age at Minneapolis Heart Institute from June 2007 through February 2011. They examined the heart rate control with beta blockade and the radiation dose with varied scan modes. Their goal was to compare the image quality and radiation dose.

Results showed high image quality was maintained in patients despite decreased radiation exposure. Overall, 17 patients underwent surgery, and the surgical findings correlated with the CTA results in all the cases.

"We found that the newer imaging modes decrease the radiation dose between four-fold and seven-fold, without loss in diagnostic accuracy or image quality," Han said. "The estimated radiation dose reduction over traditional angiography is even greater. The aggressive use of beta-blockade to slow the heart rate, in combination with the newer scan modes, allows for a very low radiation dose in this young patient population."
SOURCE: The Sixth Annual Scientific Meeting of the Society of Cardiovascular Computed Tomography in Denver, July 14-17