Imaging for juvenile angiofibroma

Juvenile angiofibroma presents characteristic imaging signs, many of which allow diagnosis and accurate estimation of extent without recourse to the d angers of biopsy. The diagnosis by computed tomography (CT) is based upon t he site of origin of the lesion in the pterygopalatine fossa. There are two constant features: (1) a mass in the posterior nasal cavity and pterygopal atine fossa; (2) erosion of bone behind the sphenopalatine foramen with ext ension to the upper medial pterygoid plate. Good bone imaging on CT is esse ntial to show invasion of the cancellous bone of the sphenoid. This is the main predictor of recurrence: the deeper the extension, the larger the pote ntial tumour remnant likely to be left following surgery. The characteristi c features on magnetic resonance imaging (MRI) are due to the high vascular ity of the tumour causing signal voids and strong post-contrast enhancement . MRI shows the pre-operative soft tissue extent of angiofibroma optimally, but its more important application is to provide post-operative surveillan ce: to show any residual or recurrent tumour, record tumour growth or natur al involution and monitor the effects of radiotherapy.