Echoencephalography ( Echo EG) - Causes, Symptoms and Treatment .MF .
Echoencephalography (EhoEG) - noninvasive brain studies using ultrasonography (ultrasound frequency of 0.5 MHz to 15 MHz / s).Sound waves of this frequency are capable to penetrate through body tissue and reflect on all the surfaces lying on the boundary of fabrics of different composition and density (soft tissues of the head, the skull bones, meninges, brain tissue, cerebrospinal fluid, blood).Reflects the structure may be a pathological formation (crush lesions, foreign bodies, abscesses, cysts, hematomas, and others.).
Indications echoencephalography (EhoEG)
Children up to 1.5 years, not yet overgrown fontanelle, which is carried out through research EhoEG to evaluate all the brain structures.In adults echoencephalography is used primarily for the detection of space-occupying lesions of the brain during the following pathologies:
diffuse and localized swelling of the brain,
inflammatory brain disease,
other cerebral diseases.
Echoencephalography (EhoEG) is used to diagnose diseases:
brain ischemia, stroke
concussion, brain contusion
vegetative-vascular dystonia (VVD)
Violation of cerebral blood flow
ears Intracranial pressure
stroke EhoEG research
survey produced mostly lying down, consistently with the right, then to the left side of the head from the forehead to the occipital region.The most constant pulse echo is reflected from the midline structures of the brain (the transparent partition, the third ventricle, the pineal gland), named "M-echo".
There are no contraindications.
Echoencephalography (EhoEG) decoding results
Echoencephalography (EhoEG) base on the registration of ultrasound reflected from the boundaries of intracranial structures and environments with different acoustic impedance (the bones of the skull, brain matter, blood, CSF).In neurological practice it introduced Leksell Swedish physician L. (L. Leksell, 1956).Intended for this device creates an exciting echoencephalograph generating momentum and allows the registration of the reflected echo signal on the oscilloscope screen (echoencephalography), which can be recorded and playback (actual echoencephalography).
During echoencephalography echolocation (emission method) mode can be used.This uses the same piezoelectric transducer for emitting and receiving the reflected ultrasound from brain structures, and when the transmission mode localization signal emitted from a piezoelectric transducer is received by the other piezoelectric element.The resulting thus echoencephalogram make initial complex - an echo of the soft tissues of the head and the skull bone directly below the ultrasonic probe;echoes from different intracerebral structures and finite complex - echoes from the inner surface of the skull bones and soft tissues of the opposite side.
From the echoes of intracerebral structures of the most important is the signal with the highest amplitude - M-echo (the first diagnostic criteria Leksell) reflected from the middle of the brain structures located in the sagittal plane (III ventricle and its walls, transparent dividing wall, a large crescent-shaped appendage, hemisphericslot epiphysis);
located on either side of the M-echo signals further significantly smaller amplitude (second diagnostic criterion Leksell) in the norm are usually a reflection of the walls of the lateral ventricles.
Normally structure forming M-echo, arranged strictly in the sagittal plane and are at the same distance from the symmetry points of the right and left sides of the head, so echoencephalogram in the absence of pathology M-echo signal are equally spaced from the initial and final complexes.
deviation median M-echo more than 2 mm in one of the parties must be regarded as a manifestation of pathology.The most informative indicator of the presence in the supratentorial space volume of the pathological focus (tumor, abscess, local cerebral edema, intracranial hematoma) should be considered as the displacement of the median M-echo in the direction opposite to the location of the fire.The appearance on the EEG large number of reflected signals between the initial complex and the M-echo signal indicates the probable presence of cerebral edema.If the signal of the median M-echo is composed of two pulses or has jagged peaks and wide base, this indicates expansion III ventricle.
different number of echoes of the left and right hemispheres of the brain is considered as ultrasonic hemispheric asymmetry, which may be the cause of the pathological focus of different origin in one or both hemispheres of the brain.Additional signals from pathological
structures located in the cranial cavity (third diagnostic criterion Leksell), indicate the presence of the cranial cavity tissues with different densities.They can be of different origin and therefore should not be overestimated when determining entity determines their
concussion displacement of midline structures during echoencephalography (EhoEG) does not exceed the physiological abnormalities.In focal cerebral contusion, brain tissue due to edema, the offset M-echo signal in echoencephalography (EhoEG) towards intact hemisphere may be 2-5 mm with a gradual increase to the 4th day and tends to regress during 1-3weeks.The bruised area on echoencephalography (EhoEG) can register pikopodobnye signals caused by reflection of ultrasound from small focal hemorrhages.
special znachenieehoentsefalografiya (EhoEG) acquires the compression of the brain.Possible early diagnosis of supratentorial meningeal hematoma, in which the displacement of median brain structures in the direction of healthy hemisphere appears already in the first hours after TBI, and tends to increase up to 6-15 mm.Often when echoencephalography (EhoEG) observed a direct reflection of the ultrasonic signal from the border between the hematoma and brain matter or the surrounding brain membranes.When you try to echolocation side hematoma location reflected from its boundary signal enters the initial "dead zone" and therefore echolocation hematoma is possible only on the opposite side.
Gematomnoe echo in echoencephalography (EhoEG) is a non-pulsating high-amplitude signal, registering between pulsating low-amplitude signals from the walls of the lateral ventricles and the final complex (reflection from the sensor located opposite the skull wall).Please note that in case of damage and swelling of soft tissues of the skull echoencephalography (EhoEG) shows a significant difference in the distance to the end systems, which often leads to errors in the interpretation of research results.In these cases, you should focus not on the initial and the final set of signals from the inner surface of the bone to the M-echo with subsequent determination of the magnitude of its displacement by the known formulas.
At bilateral hemispheric hematomas, with hematomas of the posterior fossa, as well as localization of basal lobnopolyusnoy and volume of hemorrhage diagnostic value echoencephalography (EhoEG) method is reduced, as is losing its essential definition of displacement of median brain structures.In these cases, the diagnostic capabilities of the multi-dimensional echoencephalography (EhoEG), in which through the use of special nozzles wound "dead" space and angle change input is achieved over a wide range of ultrasound.
In observing the dynamics of traumatic disease of the brain determine the size of the ventricular system (basically largest ventricular index) and the value of their pulsation (in percentage of the M-echo).Gain ripple is usually correlated with an increase in intracranial hypertension.Normalization ripple and the size of the ventricular system in echoencephalography (EhoEG) is an indication of a favorable course of traumatic brain disease.The complete absence of pulsation on echoencephalography (EhoEG) is an additional criterion, testifying to stop cerebral blood flow in cases of terminal coma.
In recent years, methods have been developed and the multi-EhoEG ehopulsografiya allowing to assess the shape and amplitude of the pulse echo from the walls of blood vessels and the ventricular system, determine the extent of deployment of vessels and to judge the severity of intracranial hypertension.
main advantage of the method is that it helps to diagnose the disease, leading to the displacement of the structures of intracranial middle cerebral line.Currently echoencephalography increasingly replaced by computed tomography (CT) and nuclear magnetic resonance (NMR).