To enhance the comparability of research results, a uniform terminology is proposed for the description of the duration of transient hyperechoic images of white matter seen on cranial ultrasound scans of very-low-birthweight infants. The term 'flare' should be restricted to any hyperechoic image that resolves completely without any abnormality in its place. A flare should be termed 'brief' if it resolves within 6 days of its appearance, 'intermediate' if it disappears between 7 and 13 days after onset, and 'prolonged' if it disappears on day 14 or later.