Anterior intercavernous sinus but not inferior intercavernous sinus was found in the cadaver (a) or CE-MRI image (b: sagittal, c: horizontal, d: coronal).

<p>AIS: anterior intercavernous sinus; BA: basilar artery; BS: basilar sinus; CS: cavernous sinus; DSS: dorsum sellae sinus; H: hypophysis; ICA: internal carotid artery; OP: optic nerve; SH: stalk of hypophsis; SP: sphenoid sinus. Direction: A-superior; P-posterior; S-superior; I-inferior.