1 Department of Radiology, Royal Melbourne Hospital, Parkville, VIC, Australia. Electronic address: jeremy.lim@mh.org.au.
2 Department of Pathology, Royal Melbourne Hospital, Parkville, VIC, Australia.
3 Department of Neurosurgery, Royal Melbourne Hospital, Parkville, VIC, Australia.
4 Department of Radiology, Royal Melbourne Hospital, Parkville, VIC, Australia; Department of Radiology, The University of Melbourne, Parkville, VIC, Australia.