Coronal CT head scans (Fig 4.20; postenhancement) from the patient whose visual fields are shown in Fig. 4.19. The left scan, performed on a Delta 25 scanner, is before therapy; the right scan, performed on a GE 8800 scanner is after two weeks of bromocriptine therapy, 2.5mg three times per day. In (a), the scan shows an enlargement of the pituitary fossa and an enhancing mass extending inferiorly into the sphenoid sinus, superiorly into the chiasmatic cistern, and abutting on the third ventricle. In (b), the scan shows a marked reduction in tumour size, with regression of the suprasellar extension. The chiasmatic cistern is now largely free of tumour, apart from a finger-like process to the left of the midline. The intrasellar high density is present in the pre-enhancement scan and represents calcification within the tumour.
