60 year old with metastatic breast cancer. Now with new stroke seen on MRI. Signs and symptoms: new stroke stroke seen on brain MRI. CTA of intracranial circulation:65 cc of omni-350 is administered for this study.3-D reformatted images of this study were obtained utilizing a independent workstation. These images were utilized for interpretation on this exam. Additional 2-D reformatted images as well as MIP images were also utilized.CTA of intracranial circulation:Examination demonstrates patent and normal appearing bilateral internal carotid arteries across to skull base and in their supraclinoid portions. There are normal appearing patent bilateral posterior communicating arteries.Bilateral ophthalmic arteries are also visualized and unremarkable.Bilateral anterior and middle cerebral arteries with no evidence of pathology. Anterior communicating artery is unremarkable.There is a small left vertebral artery (hypoplastic nondominant). The left pica is visualized and unremarkable. The distal portion of left vertebral artery is extremely small and hypoplastic. This is a normal anatomical variation.The patent dominant right vertebral artery is also very small in size in a uniform fashion. The right pica is visualized and unremarkable. The basilar artery is small in it's caliber in a uniform fashion however remains patent throughout its course.The small size of the vertebral -- basilar system is believed to be secondary to prominent bilateral posterior communicating arteries.None infuse head CT:Examination again demonstrates a large area of vasogenic edema surrounding a mass in the right lateral aspect of the cerebellum measuring approximately 34 x 25-mm in size as was noted on prior MRI exam. There is significant mass effect on the fourth ventricle and anterior displacement and partial collapse of the fourth ventricle. This results in early onset of hydrocephalus of supratentorial ventricular system. Mass-effect in the posterior fossa and results in minimal effacement of the quadrigeminal plate cistern as well.Images through supratentorial space again demonstrate a focus of attenuation in the left periventricular white consistent with patient's known acute stroke described on prior MRI. There is no evidence of hemorrhagic transformation. There is no evidence of any new finding since prior exam.
1.CTA of intracranial circulation demonstrates no detectable abnormality of bilateral internal carotid arteries, middle and anterior cerebral arteries and their branches. There are prominent bilateral posterior communicating arteries. There is small caliber of bilateral vertebral arteries and basilar artery in a uniform fashion which is believed to be due presence of large bilateral posterior communicating arteries. There is however no evidence of any definitive vascular lumen compromise of the vertebral -- basilar system infectious carotid disease and or dissection.2.None infuse head CT demonstrates right cerebellar tumor with surrounding vasogenic edema and mass effect on the fourth ventricle. Resultant mild hydrocephalus and supratentorial ventricles. These findings remain stable since prior MRI exam. Stable left periventricular white matter stroke with no interval change.