Magnetic resonance imaging of intracavernous pathology

To evaluate the usefulness of magnetic resonance (MR) imaging of intracavernous pathology, T1-weighted spin echo images of four vascular lesions and 10 neoplastic lesions with surgically confirmed cavernous sinus (CS) invasion were reviewed retrospectively. In one case of traumatic carotid-cavernous fistula (CCF) and one of dural arteriovenous malformation (AVM), the internal carotid artery (ICA) and rapid shunted flow were depicted as signal voids, and the relationship between the ICA and shunted flow was clearly shown. Normal venous flow appeared as a low-intensity area and was observed even in the presence of the CCF and dural AVM. In two cases of thrombosed aneurysms, the thrombosis was clearly demonstrated, along with patent arterial flow in one case; in the other case, however, it was impossible to differentiate patent arterial flow from calcification. The intensity of all neoplastic lesions was similar to that of the cerebral cortex. The relationship between the ICA and the tumors was clearly demonstrated. The visual pathways were also plainly shown unless they were involved, or markedly compressed, by tumor. CS invasion was strongly associated with four findings: 1) encasement of the ICA by the tumor; 2) marked displacement of the ICA; 3) absence of low intensity, which reflects normal venous flow, in the CS; and 4) extension of extrasellar tumors to the medial wall or of intrasellar tumors to the lateral wall. MR imaging was judged promising in the evaluation of intracavernous pathology.