Internal carotid artery is known as the carotid sinus or the carotid bulb. The ascending portion of the cervical segment occurs distal to the bulb, when the vessel walls are again parallel. The internal carotid runs vertically upward in the carotid sheath and enters the skull through the carotid canal. During this part of its course, it lies in front of the transverse processes of the upper three cervical vertebrae. It is relatively superficial at its start, where it is contained in the carotid triangle of the neck, and lies behind and medial to the external carotid, overlapped by the sternocleidomastoid muscle, and
Intima-media thickness not satisfactory. IMT can be measured using external ultrasound in large arteries relatively close to the skin (e.g. the carotid, brachial, radial, or femoral arteries). External ultrasound methods have the advantage of being non-invasive, comparatively low cost and convenient. Deeper internal arteries, such as the coronary arteries require special intravascular catheters employing ultrasound or optical coherence tomography to measure IMT. The carotid artery is the usual site of measurement of IMT and consensus statements for carotid IMT have been published for adults and children. Often, IMT is measured in three locations: in the common carotid artery (typically at one cm