Doctors in Sheffield are testing a tiny neonatal MRI (magnetic resonance imaging) scanner to improve diagnostic accuracy in paediatric brain scans.
The ‘miniature’ scanner being pioneered at the Royal Hallamshire Hospital, which is one of only two in the world, is part of a two-year research project into the feasibility and benefits of scanning babies in the neonatal unit.
Its size – not much bigger than a washing machine – means the scanner can be metres away from the neonatal intensive care unit allowing specialist staff to be close by in case of issues.
At present, ultrasound imaging is normally used to scan the brains of newborns. However, research has shown that magnetic resonance imaging is a better tool to visualise the brain conditions seen in neonates, said the Wellcome Trust, which funded GE Healthcare to build the machines.
“Key reasons for the lack of utilisation of magnetic resonance in neonate imaging are that the equipment is often bulky, difficult to site and therefore usually placed in separate and often distant areas of hospitals. There is a huge need for a dedicated, bespoke magnetic resonance imager that addresses these issues,” the Wellcome Trust saidin a statement explaining the reasons for founding the project.
Prof Paul Griffiths, who teaches radiology at the University of Sheffield and is specialised in diseases of the developing brain, said that MRI was better at showing the structures of the brain and abnormalities more clearly.
Ultrasound of the brain is possible in newborn babies only because the bones in their skull are not yet fused, meaning sound waves can travel through the two soft spots between the bones, the fontanelles.
“Ultrasound is cheap, portable and convenient, but the position of the fontanelles means there are some parts of the brain which cannot be viewed,” Prof Griffiths told BBC.
“MRI is able to show all of the brain and the surrounding anatomy, making the images easier to explain to parents.
“From a diagnostic point, the big advantage is that MRI is able to show a wider range of brain abnormalities, in particular those which result from a lack of oxygen or blood supply.”
So far the scanner, built by GE Healthcare with funding by the Wellcome Trust, has been used to scan 40 babies.
Two prototype 3 Tesla neonatal MRIs were eventually built, the other is in Boston Children’s Hospital in Massachusetts and is not currently in use. Both machines are still used purely for research and have not received the green light for clinical use yet.
Another machine, called a 1.5 Tesla MR scanner, was created at Cincinnati Children’s Hospital where a small-bore magnet designed for imaging adult knees was adapted into one suitable for imaging an infant’s whole body.
Prof Griffiths told BBC that the next step would be to do a trial in premature babies to compile definitive evidence that MRI produces a better diagnosis and whether it altered the clinical management of children.
In the UK, five in every 1,000 newborns suffer brain injury, and nearly one in five die from it, GE said in a statement released when it received the grant to build the machines in 2011.
Survivors are at risk of developing long-term neurological problems. Faster and more accurate diagnosis could help improve clinical outcomes, the company said.