In addition, radiographic investigations
such as X-ray may reveal asymmetric swelling,
subcortical cysts without either erosions or
proliferative bony reaction and ‘geodes’, which
are punched-out erosions with sclerotic margins
characterised by overhanging edges. Ultrasound
is being used in diagnostic cohort studies
in some centres where the aim is to identify
features present during an acute episode of
gout, specifically focusing on periarticular soft
tissue oedema and hypervascularity that occurs
in and around joints.