Reason: preop planning for tumor resection. Left side Vestibular schwannoma History: hearing loss, gait difficulty, balance The CSF spaces are appropriate for the patient's stated age with no midline shift. There is a 38 x 43 mm axial dimension mass in the left cerebellopontine angle cistern which is multi-cystic and enhances partially. It extends into the left internal auditory canal and does not appear to have changed compared to the prior exam. There is associated mass effect with compression of brainstem. The brainstem is shifted towards the right side Temporal horns of the lateral ventricles are mildly dilated. The mass distorts the adjacent seventh and eighth nerves as well as the fifth nerve. No abnormal enhancing mass lesions are appreciated intracranially. No intracranial hemorrhage is identified. No edema is identified within the brain parenchyma.Normal vascular flow voids are present in the distal carotid and vertebral arteries, the basilar artery and the proximal anterior, middle and posterior cerebral arteries as well as the internal cerebral veins and superior sagittal sinus.The visualized portions of the paranasal sinuses are clear. The visualized portions of the mastoid air cells are clear. The visualized portions of the orbits are intact.
1.Left cerebellopontine angle cistern cystic mass. 2.Examination was performed for stereotactic guidance during surgery.