The arterial anastomotic ring that connects the internal carotid arteries
, and vertebrobasilar circulation by communicating arteries is called circle arteriosus cerebri.
The bilateral internal carotid arteries
were also evaluated for the presence of plaques.
Both common carotid arteries are deeply situated at the root of the neck, become more superficial in the carotid triangle, and divide into the external and internal carotid arteries
. The ICA is accompanied by the internal jugular vein and the vagus nerve courses within the carotid sheath along the pharynx to reach the skull base, where it enters the middle cranial fossa through the carotid canal.
Looping or tortuosity of internal carotid arteries
can also be observed with advancing age (2).
Patients undergoing dialysis, arterio-venous grafts or fistulas in either arm, history of cerebrovascular disease or cardiac insufficiency, notable hemodynamic disturbances such as hemorrhage or onset of anemia in the previous 3 months, smoking, alcohol or caffeine use in the previous two days, sonographic evidence of vertebral artery occlusion or plaque formation in common carotid arteries and internal carotid arteries
were excluded from the study.
Internal carotid arteries
are more commonly injured than the vertebral arteries [2, 7].
Vessel wall enhancement of both internal carotid arteries
((c), arrows), and the right vertebral artery ((d), arrow), visible on a "dark blood" sequence.
Carotid artery stenosis (CAS) is defined as narrowing of the common and internal carotid arteries
. Between 5% and10% of the general population aged over 65 years has an asymptomatic CAS of 50% or greater.7 The prevalence of asymptomatic CAS 50% or greater was highest in patients with PAD.
There was associated mass effect on the optic chiasm, and superolateral displacement of the bilateral internal carotid arteries
. There was no hydrocephalus or vascular encasement/narrowing.
The sphenoid sinuses: computed tomography assessment of septation, relationship to the internal carotid arteries
, and side wall thickness in the Malaysian population.
Pulsatile flow in the internal carotid arteries
was never interrupted .
However, unusual hemodynamic flow including unusual curve, color aliasing [Figure 1]b, and high-velocity flow (right 210 cm/s and left 208 cm/s) within both mid internal carotid arteries
were acquired with the lower frequency probe.