CT evaluation of nonventricular CSF space disease.

Most of the central nervous system lesions betray themselves by an alteration in attenuation, ventricular shift, or a variable degree of contrast enhancement. Certain lesions, however, are predominantly or exclusively confined to the nonventricular CSF spaces. These lesions either deform these CSF space or are marked in them. Abnormal contrast enhancement helps in their identification. The spectrum of diseases include meningitis, isodense subarachnoid hemorrhage, isodense subdural hematoma, meningeal and subependymal neoplastic seeding, isodense tumors, and brain herniations.