Findings:
Moderate calcified atherosclerotic plaques are seen involving the aortic arch and the supra-aortic branches in the origins without any significant stenoses.
Atheromatous mixed plaques promote stenosis in the transition of common carotid arteries to the internal carotid artery on the right side (>80%). The right internal carotid artery above this lesion remains patent but of reduced caliber and shows reduced enhancement in the terminal right ICA.
No significant stenosis is seen on the left side.
There are tortuosity and kinking of the vertebral arteries bilaterally, which show no hemodynamically significant changes.
Absent right A1 segment. Fetal origin of the left PCA. The intracranial circulation is otherwise unremarkable without evidence of any aneurysm or branch occlusion.
The dural venous sinuses are normal.
The orbits have a normal appearance and the paranasal sinuses and mastoid air cells are clear.
The soft tissue of the neck is unremarkable. Mild enlargement of the thyroid gland is noted.
Moderate centrilobular and paraseptal pulmonary emphysema is noted. A small spiculated nodule apical segment of the right upper lobe, measuring approximately 1 x 1.5 cm.
Moderate degenerative changes of the spine are seen. No suspicious bony lesions.
Conclusion:
Critical stenosis of the right internal carotid artery. No further significant stenosis.
Incidental finding of a 1 x 1.5 cm measuring right upper lobe pulmonary nodule. Further evaluation with CT chest is advised.