New ultrasound technique for imaging defects in babies' hearts

28 March 2011

The Medical Imaging Laboratory in Trondheim, Norway, has developed a new ultrasound technique that gives an enhanced ability to discover heart defects in newborns.

Colour Doppler imaging has been the standard in ultrasound since the late 1980s. MI Lab’s new ultrasound method, called blood flow imaging (BFI), provides two-dimensional blood flow information by visualising blood speckle movement superimposed on colour Doppler images.

The resulting pattern displays blood flow regardless of the ultrasound beam orientation — providing greater information about flow direction as well as a more intuitive visualisation. Blood flow rate can also be measured, and doctors will soon be able to determine the actual volume of blood flowing through normal and pathological openings.

“Making the correct diagnosis is the greatest challenge facing paediatric cardiologists,” explains Siri-Ann Nyrnes, Consultant at the Paediatric Department of St Olav’s Hospital. “The organs are so small, and current ultrasound imaging can only provide limited information. A cardiologist needs many years of experience to be able to make a diagnosis with any certainty.”

In a pilot study, researchers examined 13 children with ventricular septal defect (a hole in the wall between the right and left ventricles of the heart, the most common heart defect in newborns). Using both new and conventional blood flow imaging methods, the researchers concluded that compared to the colour Doppler, the new method provides a significantly more detailed image of blood flow.

“The images in this study were created by the physician and technician working together, so the latter could see first-hand what we physicians are contending with, and what we need in order to improve our diagnostics,” says Dr Nyrnes. “The method is being refined with each patient.”

Now MI Lab is taking the method a step further by using plane wave imaging, which can generate an image more quickly. A pilot study of five newborns indicated that plane wave imaging yielded 5-10 times more images per second, with a substantially higher image quality.

“Quantifying the blood flow is our next objective,” says engineer and research fellow Lasse Løvstakken. “Ultimately we want to develop this method to provide blood flow information in 3D.”