Published online by Cambridge University Press: 29 June 2007
A new imaging technique is described, in which photographic subtraction as practised in angiography, is combined with Gadolinium enhanced Magnetic Resonance (GdMR)imaging and applied to the investigation of the paranasal sinuses and skull base. The densities on the subtraction image are dependent upon the blood supply of the tissues examined, thus producing a record of their vascularity: in effect a vasculogram. The method has proved to be technically feasible, and is advantageousin certain situations, particularly those in which the anatomy is complex as in theskull base or where normal structures havebeen distorted by previous surgery. The technique provides a more accurate record of tumour extent than that shown on unsubstracted GdMR scans.