Pitfalls in computed tomographic evaluation of the cavernous sinus

Computed tomography (CT) is the diagnostic procedure of choice in cavernous sinus evaluation. Two patients are reported with painful ophthalmoplegia due to metastatic carcinoma to the cavernous sinus in which initial CT scanning was considered to be normal. These cases illustrate the necessity of thin tomographic sections (5 mm or less), multiple projections (axial, coronal) and large doses of intravenous contrast medium (bolus and drip infusion). Careful technique is essential in order to thoroughly evaluate the parasellar region and avoid a false-negative CT examination.