Intraoperative US of the pituitary gland. Work in progress

PURPOSE: To evaluate the use of ultrasound (US) of the pituitary gland during transsphenoidal surgery as a means of detecting microadenomas in patients with Cushing disease. MATERIALS AND METHODS: Thirteen patients with Cushing disease and one with acromegaly underwent US during transsphenoidal surgery. Mechanically oscillating transducers (10 MHz [n = 8] or 15 MHz [n = 6]) mounted on a 15-cm-long probe were used. RESULTS: Seven adenomas were definitely visualized, two were poorly seen, and four were overlooked. Small tumors (<5 mm in diameter) tended to be hypoechoic; larger ones, hyperechoic. All four overlooked adenomas were imaged with the 15-MHz transducer. The cavernous sinuses and internal carotid arteries could be seen, but minimal invasion of the medial wall of the cavernous sinus could not. CONCLUSION: Pituitary microadenomas can be detected with transsphenoidal US; however, evaluation of larger series with instrumentation developed specifically for transsphenoidal application will be necessary to determine the ultimate value of this technique.