Evaluate/monitor for neurovascular assessment. The current invasive squamous cell cancer concern for sinus/skull/left ORBIT/current artery. CTA of intracranial circulation:45 cc of Omnipaque 350 is administered for this exam.Vertebral -- basilar system.Taken bilateral vertebral arteries, basilar artery, posterior cerebral arteries and superior cerebellar arteries. It is some mild intracranial atherosclerotic disease with moderate to severe compromise of the origin and proximal portion of the right superior cerebellar artery and high-grade stenosis of the perimesencephalic component of right superior cerebellar artery. Atherosclerotic irregularity of basilar artery and posterior cerebral arteries with no vascular lumen compromise. There is no evidence of tumor involvement/encasement of these vasculature from patient's known skull base destructive tumor.Right internal carotid is patent across the skull base and mid neuritis of compromise of the lumen or encasement by tumor in the skull base. The right anterior and middle cerebral arteries and their branches are well visualized and unremarkable. There is hypoplastic right A1 segment of anterior cerebral artery. There is a single trunk of the anterior subdural tree beyond the anterior communicating level consistent with azygos anterior cerebral artery.Left internal carotid artery demonstrate slight decreased in its caliber is pre-cavernous and its posterior genu within the cavernous sinus. This appears to be result of extension of tumor into the left cavernous sinus which applies to mass effect on the left internal carotid artery anteriorly. In the left internal carotid artery proximal and distal to these segments demonstrate normal caliber. There is no evidence of high-grade stenosis of the muscle and no areas of an aneurysm is identified. Cavernous carotids demonstrate heavy calcifications bilaterally. The branches of left anterior and middle cerebral arteries are unremarkable. There are no posterior communicating arteries visible.  Nonenhanced head CT:Examination demonstrates a large destructive mass in the skull base primarily on the left however with extension across the midline to the right side. The tumor destruction involves the left carotid canal and left cavernous sinus. There is also extensive postoperative changes of left maxillary sinus left nasal cavity, sphenoid sinus. These findings were described more in detail on prior CT of soft tissues of neck.Images through the intracranial space demonstrate no evidence of intracranial hemorrhage, edema, mass-effect, midline shift or hydrocephalus.There is evidence of minimal periventricular low attenuation of the left posterior frontal -- parietal which was noted on prior MRI exam. Bilateral posterior frontal cortical and subcortical low attenuation likely local small old strokes are again identified and unchanged since prior MRI exam.
1.Non-infused head CT demonstrate no evidence of acute intracranial process. Small areas of encephalomalacia of bilateral posterior frontal -- parietal lobes remains stable since prior MRI exam. Extensive destructive bony lesion of the skull base with involvement of left cavernous sinus and left carotid canal is partially visualized on this exam.2.CTA of intracranial circulation demonstrate minimal compromise of the lumen of the pre-cavernous left internal carotid artery as well as posterior genu of left internal carotid artery. There is no evidence of any vascular aneurysm or any significant compromise of any intracranial vasculature secondary to tumor encasement. There is evidence of intracranial atherosclerotic disease with moderate stenosis at the origin of the right superior cerebellar artery and perimesencephalic component of left superior cerebellar artery. Minimal atherosclerotic vascular irregularity of other intracranial vasculature with no hemodynamically significant stenosis. There is azygos anterior cerebral artery as described above. 