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.”