Researchers at the Johns Hopkins Children's Center in Baltimore have found a way to minimise radiation exposure in children who require repeat CT scans, it was announced in October 2013. According to a report in the Journal of Neurosurgery, this reduction was achieved without compromising diagnostic accuracy or affecting treatment decisions.
Typically, a CT scan will take around 32-40 snapshots or 'slices' of the brain. Here, the team took only seven, reducing exposure by an average of nearly 92%. Contrary to expectations, this did not affect the clarity of the images.
Over a period of five years, the team looked at 50 young patients (aged 17 and under) who suffered from hydrocephalus. Characterised by excess fluid in the brain, the condition requires periodic surgeries and a CT scan before every procedure.
The repetitive nature of these scans has historically been a concern. Ionising radiation is implicated in the development of certain cancers due to the risk of damage it poses to DNA - in fact, it is estimated that up to 2% of all cancers stem from exposure to medical radiation.
"We have been searching for ways to minimise radiation exposure in kids without sacrificing the diagnostic accuracy of the images - which is no easy feat - but we believe our limited-slice CT scans achieve that balance," said lead investigator Dr Edward Ahn.