Ultrasound B-scan
Ultrasound B-scans are used to examine the internal structures of the eye in detail. B-scanning is especially informative for diagnosing retinal detachment, gross changes in the vitreous, and tumors.
Ultrasound examination in B-scan mode. or B-mode, 2D transverse image eyeball and eye sockets. The image is reproduced in shades of gray, the brightness of which depends on the strength of the echo. Strong echo waves appear white, weaker ones appear gray. Examples of strong echoes include retinal tissue, sclera, and calcifications. Weaker echoes are seen from clusters of cells within the vitreous. B-mode images are easier to interpret than A-mode images. since the image obtained during B-scanning is most often similar to the macroscopic picture or microscopic image of the cross section of the eyeball.
Methodology
For B-scanning, standardized techniques are used. The immersion technique is used to examine the anterior chamber of the eye. Immersion is achieved by installing a small scleral cup (cylinder) between the eyelids; the cup (cylinder) is filled with a solution of methyl cellulose, into which the sensor is immersed. Used to study the posterior segment contact method when the sensor is placed directly on the eyeball. When performing a contact study, each segment of the eye is studied in accordance with a specific system. The position of the ultrasonic sensor is selected in such a way as to exclude the passage of a wave or echo through the lens system, so as not to provoke artifacts. Ultrasound information is most often captured using Polaroid snapshots of special frozen images that are selected during the examination, although this technique does not capture the dynamic information of the ultrasound examination.
27) Dopplerography (one-dimensional and two-dimensional) principle of the method, indications, scope of application.
Dopplerography is one of the most elegant instrumental techniques. It is based on the Doppler effect. The effect consists of a change in wavelength (or frequency) when the source of the waves moves relative to the device receiving them. As the source approaches the receiver, the wavelength decreases, and as it moves away, it increases. There are two types of Doppler studies - continuous (constant wave) and pulsed. Continuous Dopplerography Principle: generation of ultrasonic waves is carried out continuously by one piezo-crystal element, and registration of reflected waves by another. In the electronic unit of the device, two frequencies of ultrasonic vibrations are compared: those directed at the patient and those reflected from him. By the shift in the frequencies of these oscillations, the speed of movement of anatomical structures is judged. Frequency shift analysis can be done acoustically or using recorders. Indications and scope Continuous Dopplerography- a simple and accessible research method. It is most effective at high blood flow rates, for example in areas of vasoconstriction. However, this method has a significant drawback: the frequency of the reflected signal changes not only due to the movement of blood in the vessel under study, but also due to any other moving structures that occur in the path of the incident ultrasonic wave. Thus, with continuous Doppler ultrasound, the total speed of movement of these objects is determined.
Pulsed Dopplerography. Principle:
It allows you to measure speed in prescribed by the doctor control volume area. The dimensions of this volume are small - only a few millimeters in diameter, and its position can be arbitrarily set by the doctor in accordance with the specific task of the study. In some devices, blood flow velocity can be determined simultaneously in several (up to 10) control volumes. Scope of application:reflects full picture blood flow in use
the following area of the patient's body. The results of a pulsed Doppler examination may be
presented to the doctor in three ways: 1) in the form quantitative indicators blood flow speed, 2) in the form of curves
3)audially, i.e. tone signals at the sound output of the device. The sound output allows you to differentiate by ear the homogeneous, correct, laminar flow blood and vortex turbulent blood flow in a pathologically altered vessel. When recorded on paper, laminar blood flow is characterized by a thin curve, whereas
the vortex flow of blood is displayed by a wide heterogeneous curve.
Color Doppler mapping The method is based on color coding of the average Doppler shift of the emitted frequency. In this case, the blood moving towards the sensor is colored red, and from the sensor - blue. The color intensity increases with increasing blood flow speed. Sometimes, to enhance contrast, a perfusate with microparticles simulating red blood cells is injected into the blood.
Power Doppler.
Principle With this method, it is not the average value of the Doppler shift that is encoded in color, as with conventional Doppler.
drovsky mapping, and the integral of the amplitudes of all echo signals of the Doppler spectrum.
Scope of application. This makes it possible to obtain an image of a blood vessel over a much larger extent and to visualize vessels of even a very small diameter (ultrasound angiography). Angiograms obtained using power Doppler do not reflect the speed of movement of red blood cells, as with conventional color mapping, but the density of red blood cells in a given volume. Doppler mapping is used in the clinic to study the shape, contours and lumen blood vessels. Using this method, narrowing and thrombosis of blood vessels, individual atherosclerotic plaques in them, and blood flow disorders are easily detected. In addition, an introduction to clinical practice Power Doppler allowed this method to go beyond pure angiology and take its rightful place in the study of various parenchymal organs with diffuse and focal lesions, for example in patients with liver cirrhosis, diffuse or nodular goiter, pyelonephritis and nephrosclerosis, etc., which is facilitated by the emergence of a class of contrast agents for ultrasound examination.
Tissue Doppler. Principle It is based on the visualization of native tissue harmonics. They arise as additional frequencies during the propagation of a wave signal in a material environment and are integral part of this signal and are multiples of its main (fundamental) frequency. By registering only tissue harmonics (without the main signal), it is possible to obtain an isolated image of the heart muscle without an image of the blood contained in the cavities of the heart. Indications, scope. Such visualization of the heart muscle, performed in fixed phases of the cardiac cycle - systole and diastole, allows non-invasive assessment contractile function myocardium
By registering only tissue harmonics (without the main signal), it is possible to obtain an isolated image
cardiac muscle without an image of the blood contained in the cavities of the heart. Such visualization of the cardiac muscle, performed in fixed phases of the cardiac cycle - systole and diastole, allows non-invasive assessment of the contractile function of the myocardium
B-scan is a technique for recognizing the internal structures of the eyes using an ultrasound machine.
It is a non-invasive method and does not cause discomfort or pain during the procedure.
Therefore, all categories of patients easily tolerate the process. Using the technique, it is possible to recognize changes in the internal structure of the eyeball when it is impossible to examine the fundus using a slit lamp. It is recommended that the examination be carried out by the surgeon who will perform the operation so that he can put accurate diagnosis.
The technique is carried out on the basis of an ultrasound machine, which is brought to eyes closed patient. First, the doctor applies a gel that eliminates the possibility of air appearing between the patient’s eyes and the sensor. The device sends ultrasonic waves into the eyeball, which are reflected and returned back. All wavelength data is displayed on the monitor screen. They are deciphered by an ophthalmologist after completion of the study.
With the help of B-scanning, the procedure is performed quickly, it is possible to determine large number deviations in normal structure eyeball.
B-scanning of the eyeballs is carried out to determine the following pathologies:
It is recommended to conduct an examination before surgery to identify the exact structure of the eyeball. The procedure is also carried out after completion of the operation to identify the patient’s tendency to recovery.
This is a non-invasive procedure, so no specific preparation is required for the study. The person must sit on a chair and close his eyes. The doctor will apply a gel that can be used to attach an ultrasound probe.
Women are advised not to wear makeup, as the gel will remove it and smear it over the eyes. It is recommended that there are no large wounds on the skin of the eyelids into which the gel can penetrate, causing pain and additional inflammation.
The technique is carried out in several stages:
There are practically no contraindications to the ultrasound technique. Therefore, even a person with strong eye sensitivity can perform it. Side effects after completion of the procedure there are no.
There are normal indicators that the device sensor detects:
If deviations are detected in one of the test results, it is recommended to repeat diagnostic test. After this, the doctor prescribes medication and surgical treatment.
Vision is restored up to 90%
It is actively used in many areas of medicine ultrasound scanning as a highly informative diagnostic method with virtually no contraindications. It is also used in ophthalmology to help accurately diagnose pathological processes in the eyes. Examination of the organ of vision in A-scan mode is also known as echobiometry of the eye.
An A-scan is an example of a one-dimensional scan. During its implementation, the following is measured:
The received information is reflected on the monitor in the form of a graph with two axes - vertical and horizontal. The obtained indicators of echobiometry of the eye are used to analyze all structures of the eye, which allows us to obtain a comprehensive picture.
Echobiometry lasts on average from 15 minutes to half an hour. Eyes must be open throughout this time. The procedure does not require the use of painkillers, so it is recommended for both adults and children.
Echobiometry of the eye in children is carried out when the indicators obtained from a slit lamp examination are not very informative.
Indications for ultrasound in children are the following conditions:
Echibiometry of the eye in adults has the same indications.
At the same time, such an absolutely safe study as echobiometry, when prescribed for children, has certain contraindications:
The listed contraindications are also relevant for adult patients.
Echobiometry is a fairly informative research method. It should be remembered that only a specialist will be able to determine what indicators are normal. A table is often used to decipher the results.
The norm for children is almost the same as for adults. In general, to calculate indicators, special formulas are used, which give an accurate answer to the question of what is the norm for echobiometry of the eye in patients of a given age.
Echobiometry is performed in a sitting position or, in as a last resort, lying down (this position is recommended for children and the elderly). To immobilize the eyeball, the doctor instills special drops. In the case of echobiometry, the sensor directly touches the organ of vision.
Today, the method is quite developed and allows one to accurately examine the eye and its internal structure.
The specialist observes on the monitor all the data that characterizes the cornea:
By comparing the average statistical data and the results obtained, the doctor determines which indicators are normal and which deviate.
Carrying out an ultrasound examination of the organ of vision allows you to avoid many pathological processes or detect them in initial stage.
My ophthalmologist prescribed this “A-Scan” to me after I suspected that my vision was deteriorating... After an examination by a doctor and a test, it turned out that in almost a year since our last meeting, it had indeed noticeably worsened. Having prescribed a number of studies that were already familiar to me and drops to improve the situation, I noticed that some new study called “A-Scan” had been prescribed, it was scary...
A similar study applies to ultrasound examinations and from these data the doctor can judge the progression of myopia. The thickness of the cornea is also measured, diagnosis and monitoring of corneal diseases, lens thickness, clarification of the form of glaucoma (if present or suspected), detection of subatrophy of the eyeball... and much more. In short, anyone who is concerned about the health of their eyes can easily find information on the Internet about this type of diagnosis.
It turned out to be completely painless and quick. The device intended for this study - see in the main photo for the review. This is exactly what it looks like and is even called the same.
Before the examination, a drop of some drops was dropped into both eyes... Apparently painkillers, but there is nothing painful in the examination, this is simply done so that the patient does not twitch from the touch of the device.
The entire study lasted about 10 minutes. The doctor brings some kind of thing (like a pencil lead) to different places to each eye and waits a couple of seconds until some indicators appear on the screen. Then, in the same eye, this thing touches another place, etc. 3-4 times (I don’t remember exactly). It’s not a pleasant feeling, but it’s because of the drops... because you have to look straight, and my eyes began to water. In general, those who can tolerate eye drops normally are generally happy. And I (why did I do this?) also had my eyes painted (but I don’t need to put in contact lenses at all, and makeup doesn’t really interfere if my eyes don’t water for any reason).
Well, they do the same with the second eye. This device calculates everything on its own, the doctor prints it out, and the study is ready.
I really liked the fact that usually, in order to monitor your health, you need to look for a competent doctor (and there are not enough of them in our time), or at least a doctor who inspires confidence in you (and I have a pathological suspicion and for me such doctors and in does not exist in nature), but in in this case, when similar devices appeared, in absolutely any medical center. center or clinic (where it is... personally, I’m in medical institute performed this diagnostic) you can obtain accurate data regardless of the talent of the operator who performs this diagnostic. And with the finished printed study, go to your doctor, who will tell you what’s wrong with your eyes and make the necessary appointments. in my case, the diagnosis was carried out by my doctor herself and she deciphered it herself.
I am, of course, very glad that such devices have appeared in our clinics... before, when I monitored the health of my eyes, the doctors constantly relied only on their conjectures, experience and some kind of knowledge acquired in an unknown place (well, for me this is not impressive, in any case), thanks to the exact figures received from the device, although the diagnostic accuracy becomes greater, there is less speculation and efficiency measures taken- higher, in my opinion.
In addition to this study, to complete the picture, they usually prescribe a “B-scan” (this is a study of the posterior axis of the eye, while an A-scan is intended to study the anterior-posterior axis) of the eyes, after which full conclusions are drawn (after these two research). Of course, it was prescribed to me too, and once I’ve done it, I’ll write a review about it. Both of these diagnostics are inexpensive and very accessible to almost everyone.
The only contraindications for it are an eye injury or an open wound.
Ultrasound diagnostics is often used to detect eye diseases. This is a safe, effective and informative method practiced by ophthalmologists. With its help they study the slightest changes in the eyeball, the muscle structure is assessed, and pathological formations are determined.
Decreased visual acuity negatively affects the quality of life. Therefore, you need to consult an ophthalmologist in time. Then the chances of recovery increase. After the examination, the specialist prescribes an examination to clarify or make a diagnosis.
One of the common ways to determine diseases is ultrasound diagnostics of the eye. This is a manipulation based on the penetration and subsequent reflection of high-frequency waves from tissues. The computer receives the information. At the final stage, the image appears on the monitor.
Ultrasound of the eye is performed using modern equipment. This technique does not require much time, large financial costs and special training. During the diagnosis, the specialist studies the structural features of the retina, muscles, and lens. The procedure is prescribed for staging final diagnosis, before and before surgical intervention. The technique is also used to monitor the dynamics of the disease.
Ultrasound examination of the eye is a popular way to identify pathological processes and changes in internal tissues.
The procedure is indicated if there are numerous problems:
Ultrasound examination is widely used in ophthalmology. Non-invasive method applies to patients of all ages. This perfect solution for screening and searching for changes. A miniature sensor detects pathological processes of unusual configuration and localization. Therefore, in patients who contact a medical facility in a timely manner, diseases are detected on early stage. This important advantage which ensures successful treatment.
Ultrasound does not affect a person’s normal life. Some patients experience slight discomfort. Such unpleasant symptom passes soon. If a person works at a computer or drives vehicle, after diagnosis you need rest. You cannot engage in the above activities, since excessive visual strain is unacceptable.
In clinics and public hospitals equipped with innovative scanners, high-quality ultrasound diagnostics of the eye is carried out. Qualified specialists different methods are used:
Ultrasound diagnostics eyes is built on the principle of echolocation. This is a method for determining diseases of the organ of vision, which has many advantages: harmlessness, simplicity and convenience, affordability of the service. An important advantage is painlessness, since there is no need for injections or incisions.
Ultrasound diagnostics of the eye can be performed on patients who do not have the following contraindications:
There are no other contraindications. Therefore, ultrasound diagnostics of the eye finds wide application in private clinics and public medical institutions. It is used to identify tumors, congenital features of the organ of vision, inflammatory processes. Research recommends for adults, children, and pregnant women.
Ultrasound diagnostics of the eye is carried out as prescribed by a doctor in the presence of diseases. It is also possible to conduct research in for preventive purposes. This prevents the development of many eye diseases.
No special preparation is required for the diagnostic procedure. A special rule applies to representatives of the fair sex. Before conducting the study, you need to remove your makeup because the sensor is placed on the upper eyelid.
Depending on the data that the ophthalmologist needs to clarify, there are two types of research:
To conduct ultrasound, medical institutions are equipped with modern equipment. This refers to an A/B scanner and pachymeter. These are new generation devices that are characterized by safe operation. They provide quick calculation of IOLs using rational formulas. With the help of improved devices, intraocular tumors, partial or complete retinal detachment are detected, traumatic injuries organ of vision. The equipment is installed in medical institutions, whose leaders prioritize practical solutions. It pays for itself quickly. Why? Clients are actively turning to ophthalmology clinics that provide high-quality services.
The A/V scanner AVISO is in great demand. This is a device designed by leading engineers. Ultrasound equipment was produced by the French company Quantel Medical. This famous manufacturer, with the help of which early and accurate diagnosis is carried out.
A/V scanner AVISO – new model, created on a PC basis. This is a device equipped with a variety of sensors. It is designed to visualize the anatomical and topographic structures of the orbit, lens, fundus and conduct detailed studies of anomalies. High accuracy of the procedure is ensured by a biometric sensor with a laser target. With the help of such a device, a person’s gaze is recorded, and the axes of the eyes and ultrasonic beams are aligned.
The scanner from the French company has important advantages:
In medical institutions that keep up with the times, a Compact Touch pachymeter is installed. This is equipment that combines several functions. It is used to perform B-scanning, pachymetry and biometrics. The device is compact in size and ergonomic. Its main advantages include ease of use, high-quality images, and an intuitive interface.
Other technical features are also important:
The Compact Touch pachymeter is an innovative “3 in 1” ultrasound equipment from the French company Quantel Medical. The global manufacturer took into account significant aspects and created an effective device. The device is a ready-made workplace a doctor who specializes in performing ultrasound examinations of the eye. You don't need a computer to display the results. Information is quickly displayed on the touch screen.
After diagnostic procedure the specialist studies the data obtained. To check the results, a table of normal indicators is used:
Decoding the results – important stage. If abnormalities are detected, the ophthalmologist prescribes treatment. He is guided by the information received and his own knowledge.
Ultrasound diagnostics of the eye is an effective method through which pathology is detected at the initial stage and internal tissues are carefully examined. If the problem is identified in a timely manner, complications can be prevented and vision can be saved. Therefore, people who care about their health come to ophthalmology clinic and use the services of qualified specialists!
