Clivus Lesions

CT and MRI images from six patients with lesions affecting the clivus:

• Case A: A heterogeneous, T2 isointense to hypointense, avidly enhancing soft tissue mass is centered within the clivus and right petrous temporal bone. An additional ring-enhancing lesion is seen in the left posterior occipital lobe. Note the normal appearance of the pituitary gland and preservation of the nasopharyngeal mucosa.

• Case B: A homogenous expansile clival mass is present with slight intrinsic T1 hyperintense signal and intermediate T2 signal. The tumor abuts the left petrous and bilateral cavernous carotid artery flow voids. Involvement of the sellar floor is noted with upward displacement of the distinct pituitary gland. There is mild enhancement.

• Case C: A destructive mass is seen arising from the posterior clivus with effacement of the prepontine cistern and associated scalloping of the pons. The soft tissue component of the mass is low in CT attenuation with restricted diffusion, T1 hypointensity, and marked T2 hyperintensity. There is no appreciable enhancement. The mass partially engulfs the basilar artery.

• Case D: A large destructive soft tissue mass involves the clivus, sphenoid sinus, and nasopharynx. Axial postcontrast images best demonstrate involvement of the nasopharynx and longus colli musculature. T2 signal is intermediate and heterogeneous. Note the normal appearance of the pituitary gland on sagittal T1-weighted images.

• Case E: A large mass remodels the superior clivus. The epicenter is in the sellar and suprasellar regions, with marked upward displacement of the optic chiasm (accounting for the patient’s visual disturbance). Tiny hyperintense cystic spaces are seen on T2-weighted images. There is mild enhancement.

• Case F: A destructive expansile lesion is seen involving the right petroclival synchondrosis with ring and arclike calcifications suggestive of chondroid matrix.