title: Response to letter: Vrselja et al.
authors.affiliation: Trinity College, Dublin, Ireland.
authors.forename: Joseph
authors.initials: J
authors.lastname: Harbison
authors.affiliation: Kings College Hospital, London, UK d_jamesryan@yahoo.co.uk.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Ryan
mesh_terms: D002941:Circle of Willis / Q000473:pathology*; D005260:Female; D006801:Humans; D056784:Leukoencephalopathies / Q000473:pathology*; D008297:Male