[en] Cerebral angiography performed on a patient with a preliminary diagnosis of jugular foramen syndrome revealed a highly vascular malignant chemodectoma supplied mainly by the left ascending pharyngeal artery. Blood flow was determined during angiography in the extracranial branches of the carotid arteries by video dilution technique. The decrease of blood flow after partial embolization of the left ascending pharyngeal artery was also quantified. The application and value of video dilution technique in blood flow determination, together with the angiographic findings are discussed. (Auth.)