Also ... > Unlike in post hoc disease studies, the availability of pre-infection imaging data helps avoid ... That depends on why the earlier brain scans were

Also ... > Unlike in post hoc disease studies, the availability of pre-infection imaging data helps avoid ... That depends on why the earlier brain scans were done. edit - I didn't find discussion on the UK one, but an Australian study found those with some health concerns were more likely to accept the invitation. Not surprising.