Radiologists have probed changes to the brains of astronauts that could have significant implications for the future of human colonisation on the moon and Mars.

The annual gathering of the Royal Australian and New Zealand College of Radiologists in Adelaide will hear of world-first data from MRIs taken on astronauts from NASA, the European Space Agency and the Russian Space Agency.

They reveal significant changes in the brain associated with long exposure to microgravity, including Spaceflight Neuro-Ocular Syndrome, are linked to the brain's waste clearance system called glympathics.

The syndrome can have a significant impact on those in space for long periods with symptoms including vision issues, changes to the brain's structure and a shift in brain fluid.

The vision issues in particular may impact on the in-flight performance of astronauts, with about 70 per cent experiencing some level of the condition.

Lead researcher Meng Law said the study would play an important role in discovering the mechanisms behind the occurrence of Spaceflight Associated Neuro-Ocular Syndrome and the development of mitigation strategies.

While College of Radiologists president Sanjay Jeganathan said understanding the impacts of microgravity and developing measures to support the health of space travellers would ultimately help mankind become a multi-planetary species.

"Human space exploration is set for rapid development in the next decade," Professor Jegananthan said.

"The space radiology session demonstrates how radiology can support astronauts' health and documents the challenges to human physiology by prolonged exposure to low gravity."

Findings from the study will be presented at the conference on Saturday.