Doctors at the Royal Hallamshire Hospital – located in Sheffield, South Yorkshire in England – are paving the way for the use of a compact neonatal MRI scanner designed for imaging the brains of premature babies.
The machine at the Sheffield hospital is one of only two purpose-built neonatal MRI scanners in the world.So far about 40 babies have been imaged in the MRI scanner, which was built by GE Healthcare with funding by the Wellcome Trust.
According to Prof. Paul Griffiths of the University of Sheffield, MRI was better at showing the structures of the brain and abnormalities more clearly.
At present, ultrasound is normally used to scan the brains of newborns.
Ultrasound of the brain is possible in newborn babies only because the bones in their skull are not yet fused.The sound waves can travel through the two fontanelles – the soft spots between the bones.
Ultrasound is cheap, portable and convenient, but the position of the fontanelles means there are some parts of the brain which cannot be viewed, Griffiths said. He also added that 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,” he said.
MRI scans are rarely performed on severely premature babies because the risks involved in transferring and handling a sick infant can outweigh the benefits.
Griffiths pointed out that MRI machines are huge and heavy objects that are often located in the basement or ground floor of hospitals. Meanwhile, maternity units are usually higher up, or in a completely different building, so it can mean a complicated journey to get a baby to and from the scanner.
Evelina Children’s Hospital in London has a full-size MRI scanner within the neonatal intensive care unit.
The compact baby MRI machine at the Royal Hallamshire is not much bigger than a washing machine and just meters away from the neonatal intensive care unit, meaning that specialist staff are on hand in case of problems.
The concept for a dedicated neonatal scanner was originally developed more than a decade ago by Griffiths and Prof. Martin Paley of the University of Sheffield.
Two prototype 3 Tesla neonatal MRIs were eventually built – the other is in Boston Children’s Hospital in Massachusetts – although it is no longer in use.
Neither machine has regulatory approval for clinical use, and both remain purely for research.
Griffiths said the next step would be to do a trial in premature babies to show definitively that MRI produces a better diagnosis and whether it altered the clinical management of children.
It is not known how much a neonatal MRI machine would cost, should the system eventually get commercialized, but full-size scanners are typically priced at several hundred thousand pounds.
Cincinnati Children’s Hospital has a 1.5 Tesla neonatal MRI scanner that was adapted from adult orthopedic use.