Doppler ultrasound of the neck vessels and brain - Causes, Symptoms and Treatment .MF .
Doppler (duplex scanning, ultrasonography) - method of accurate, non-invasive, safe, painless and relatively rapid assessment of carotid and vertebral arteries, the venous system: hemodynamic parameters (speed and impaired blood flow) and the condition of the vessel (lesion of the vascular wall,the presence of a stenosis, a condition of vascular tone, atherosclerotic lesion).
vascular system (arteries and veins) head.
indications for carotid ultrasonography:
- transient ischemic attacks
- reversible neurological deficits, vertigo
- pulsating education neck
- suspected vascular malformation
disease - cerebral atherosclerosis
- visual disturbances
-osteocondritis of the spine.
held Doppler: in the presence of headache, dizziness, impairment of consciousness, the presence of neurological symptoms.
How is the Doppler
Due to the fact that the carotid arteries are located superficially and they are easy to inspect, they are a convenient window to evaluate the
early symptom of carotid arteries - increasing the thickness of the intima-media.This indicator reveals a tendency to develop atherosclerosis.Previously affected vascular wall at the bifurcation of the common carotid artery.Defeat vascular endothelium, it lipid deposition in macrophages, leading to the development of fibrosis, atherosclerotic plaque formation.Depending on the composition of the plaque, they can be sustained, brittle, with erosions with hemorrhage.On
erosive surfaces may form thrombi, which have the ability to break off and fall into the brain vessels.Plaques can grow by deposition of lipids and fibrous deposits, narrowing the lumen of the vessel and leading to stenosis.There are hypoechoic rim with a thin, predominantly hypoechoic with echogenic content inside a small, predominantly echogenic with small hypoechoic area, completely echogenic.It is believed that the first two types of plaques are often combined with clinical symptoms.Hypoechoic plaques - brittle, neustoyivye.Echogenic plaques - fibrous and stable.
Distinguish local and prolonged plaque -. 1.5 cm plaque can occupy one side of the vessel, may be concentric, polukontsentricheskoy.When reducing the diameter of the vessel spends more energy to overcome stenosis, the narrowing portion of the vessel pressure drops.This reduces perfusion pressure and blood flow to the brain tissues deteriorates.In the early stages this is offset by the increase in speed, but in stenosis of more than 50% of this is not enough.50% stenosis is hemodynamically significant.
A - small atherosclerotic plaque, lumen narrowed somewhat, B- later stage - the vessel stenosis, occlusion of the vessel B, T- artery tortuosity.
doplerography examination possible - extracranial and intracranial (transcranial) .
patient lies on the couch on his back, his head thrown back for a pillow.
chin of the subject turned to the side opposite the side of the survey.The study begins with a transverse scan of the lower segment of the common carotid artery to the right, tilt sensor down into the upper mediastinum.Then the sensor is carried out up to the neck for any angle bo ttom jaw.This makes it possible to determine the depth and stroke carotid bifurcation level location, to determine the presence of atherosclerotic plaques.After that include color Doppler, and consider the common carotid artery bifurcation and every twig.The use of color allows you to quickly differentiate between areas with disrupted blood flow and see the anomaly of the vascular wall, plaque, thrombus.Upon detection of anomalies is carried out a thorough investigation to determine the severity of the injury and its likely clinical significance.Then just examined and left carotid artery.
further investigated vertebral artery.They can be seen in the spinal canal, the side of the vertebral bodies and between the transverse processes of the vertebrae.The sensor is located along the neck.Peak systolic velocity, end diastolic velocity and the ratio of peak systolic velocities in the internal and common carotid arteries are of great importance in the study of blood flow, determination of% stenosis.
criteria for assessing the degree of carotid stenosis:
|% stenosis in diameter||Definition stenosis||Peak systolic velocity||peak diastolic velocity||ratio|
|0%||rate||& lt; 0.9||& lt; 0.5|
|0 - 15%||easy||& lt; 1.1||& lt; 0.5|
|15 - 50%||moderate||& lt; 1.5||& lt; 0.5||& lt; 2|
|50 - 70%||heavy||& gt; 1.5||& lt; 0.5||& gt; 2|
|& gt; 70%||critical||& gt; 2.25||& gt; 0.75||& gt; 3|
survey is conducted in B-mode, to quantify the vessel diameter, thickness of the layers of the vascular wall, the presence of intraluminal formations.
In the study in color Doppler estimated cartogram color - uniformity of filling the container, the presence of areas of turbulence, uniform filling.
In the spectral Doppler receive objective quantitative information about the nature of changes in the values of local and systemic hemodynamics.
veins study carried out in three modes - determines continuity, geometry, diameter, condition of the vascular wall, the state of the lumen, venous valves.
transcranial duplex scanning conducted through the scales of the temporal bone through the foramen magnum, transorbital through the scales of the occipital bone.
installing the sensor in front of the pinna (anterior temporal window) and above the pinna (the average temporal window) and posterior (back temporal window) visualized the rear, middle and anterior cerebral artery, posterior communicating artery, the main artery, Vienna Rosenthal, Galena,straight sinus.Transorbital (sensor on the closed upper eyelid) visualized the siphon of the internal carotid artery, ophthalmic artery.Transoktsipitalnye and transtemporal positions are determined in a sitting position and visualize the intracranial vertebral artery, the main artery, cerebellar artery, straight sinus and paravertebral venous plexus and parabazillyarnye.An obstacle for the study may be abnormalities of the cervical spine, the lack of "ultrasonic windows" or bad terms.
Doppler Ultrasound examination performed to detect disease in the arterial and venous system and its evaluation - pathogenetic and hemodynamic significance of monitoring the effectiveness of treatment, angiography and need directions to the vascular surgeon to decide on surgical treatment.
- organic changes with objective ultrasound signs - constrictive atherosclerosis, aneurysms, arteriovenous malformations, venous thrombosis, varicose veins,
- processes that do not have a specific ultrasound picture - nestenoziruyuschy atherosclerosis, angiopathy, vasculitis.
When nestenoziruyuschem atherosclerosis revealed irregularities in the structure of the intima-media of large arteries, irregular changes in echogenicity, abnormal thickening of the vessel wall narrowing of the lumen of not more than 20%.Normally, the thickness of the vascular wall is considered to be up to 0.9, the boundary values - 0,9 - 1,1.
When stenotic atherosclerosis determined atherosclerotic plaques.What matters is the structural characteristics of plaque to assess the potential ability to be a source of embolism.
When vasculitis ultrasound picture depends on the stage of the pathological process - diffuse changes of the vascular wall, the violation of differentiation of the layers, reduced or increased echogenicity, signs of inflammation.
When temporal arteritis in the superficial temporal artery and its branches revealed diffuse thickening of the wall even at low echogenicity.
When long current inflammatory process join atherosclerotic lesion symptoms.
When diabetes revealed signs of macro- and microvascular complications.
arteriovenous malformations are abnormal vasculature of various diameters or arteriovenous fistula, a vascular network of more than 200 microns in diameter.Vents greatly hypertrophied veins with hyalinosis, calcification, lipoznoy infiltration.Thinning of the vascular wall can lead to hemorrhages.Development syndrome arteriovenous shunting resulting in intracerebral syndrome "steal" and a violation of cerebral circulation.
most common abnormality of the vertebral arteries - hypoplasia .This decrease its diameter to 2 mm or less.Depending on the severity of hypoplasia and its hemodynamic significance will and ultrasound signs.Often the occurrence registered anomaly of the vertebral artery in the canal of the transverse processes of the cervical vertebrae.Typically, this anomaly does not affect the haemodynamics.
can define the structure of the anomalies of the arteries connecting the circle of Willis.
Ultrasonography may define extravasal compression - compression of the outside wall of the vessel, the germination of the vessel wall.At the cervical level frequent cause compression of blood vessels is a thyroid disease, enlarged lymph nodes, the cervical osteophytes may compress the vertebral artery.Eksravazalnye compression can be caused by cancer.All these findings require further investigation.
neurologist Kobzev SV