Atulaya Healthcare

Ultrasonography (USG) is a procedure by which images of the various organs in the body are obtained with the help of ultrasound waves. Essentially ultrasound waves are sound waves in the very high frequency range (2.5 to 5.0 MHz). At this frequency these sound waves are inaudible to the human ear.

Ultrasound waves are able to pass through body tissues to a variable degree. In the case of some body tissues they may pass through unhindered, while in other cases these waves may be partly reflected back, or absorbed by the tissue such as air cells, or be blocked completely as by bone. Those ultrasound waves that get reflected back are received by a transducer. Depending upon the signal strength of the returned waves and the time taken for the return path images can be created which show the broad outline of the organs and some of the structures in them.

Fortunately the transducer that generates the ultrasound waves can also be used to detect these waves on their return path.

Ultrasonography (USG) is widely used for diagnosis and management of many of the organs in the body, especially those within the abdomen. It provides information mostly about the structural changes in organs under examination. Repeat examinations are useful in tracking progress of disease.

No special preparation is required for this test. Ultrasonography (USG) is a non-invasive procedure which, in most instances, does not require even an injection. Anaesthesia is not required. Patients are advised to wear loose fitting clothes especially since they will be required to expose the concerned area of the body for examination.

The only part of the equipment that comes in contact with the patient is the transducer which is a small cylindrical probe held and manipulated by the person (who may be a specialist doctor or a trained technician) performing the test. The signals from the transducer are electronically processed in a machine usually kept at the bedside of the patient. Images are displayed on a monitor and recorded on paper or film or stored on a digital medium. Video images showing actual motion of the concerned body part (and the various structures that comprise it) can be seen in real time and recorded.

The echo transducer comprises several crystals each of which generates ultrasound waves of appropriate frequency on being excited by electric current. The same crystals also receive the returning ultrasound signals continuously. The signals created by multiple beams of ultrasound are then processed by a computer using dedicated software to create images of various organs in the body. These images are viewed on a monitor by the operator. Images are optimised by changing manually the direction of the transducer. Selected images are then recorded on an appropriate medium such as paper, X-ray plates or in digital format.

The computer program also provides internal callipers for measurements of various dimensions.

Ultrasonography (USG) is useful for measuring the size of various organs under examination , the presence or absence of stone disease or fluid around the organ.

Patients are required to lie down on an examination table, usually partially turned to the left side. In order to exclude any interference from pockets of air between the transducer and the chest wall a transparent non-sticking jelly is put over the area where the transducer will be placed. The transducer, a blunt flexible probe, is placed with gentle pressure at the chosen place and images reviewed on a monitor screen at various angulations to obtain the maximum information. Images may need to be obtained from different locations and angulations of the heart. You may be asked to hold your breath at times or to take a deep breath in and hold it for a few seconds in order to optimise the quality of images.

Selected images may be recorded on paper or, on any digital medium either as a video or in single frames. The test usually takes up to a half hour.

You may feel a slight pressure as the operator needs to press the transducer against the skin and fit it in between the ribs so as to avoid interference from these bones. No pain is caused. No injections are given.

The tracings are analysed on a computer using dedicated software. The data are reviewed by a doctor and a report prepared. Normally the report should be ready on the day after the test.

Please remember that similar results in different clinical circumstances may have different significance. Therefore, it is in your own interests that the reports be shown to your own doctor who recommended the procedure in the first place for the most useful interpretation of data. It is for this reason that our staff are under instructions to encourage you to seek proper interpretation of our reports from your own doctor.

There are no known risks of this procedure.

The procedure is a very useful, simple and inexpensive test that helps the doctor to take a “peep” inside the heart. Changes in structure and function of various elements in the heart can be detected with a fair degree of accuracy.Further, it is useful for assessing progress of disease and adequacy of treatment being taken.

Whereas in many forms of heart diseases it is an invaluable tool for diagnosis and management, it has only a limited use in the diagnosis of coronary artery disease.What are the limitations of the procedure?A major limitation of the test is that it is not able to directly detect disease in the blood vessels of the heart, the coronary arteries. Also it cannot provide diagnostic information about the nature of the disease process in a given location, though it can provide many useful leads.

A Doppler test is used to:

1. Detects blood clots and blocked or narrowed blood vessels in almost any part of the body, especially in the neck, arms, and legs.
2. Evaluate leg pain that may be caused by intermittent claudication, a condition caused by atherosclerosis of the lower extremities.
3. Evaluate blood flow after a stroke or other condition that might be caused by a problem with blood flow. Evaluation of a stroke can be done through a technique called Transcranial Doppler ultrasound.
4. Evaluate abnormal veins causing varicose veins or other problems.
5. Map veins that may be used for blood vessel grafts. It also can evaluate the condition of grafts used to bypass blockage in an arm or leg.
6. Find out the amount of blood flow to a transplanted kidney or liver.
7. Monitor the flow of blood following blood vessel surgery.
8. Find out the presence, amount, and location of arterial plaque. Plaque in the carotid arteries can reduce blood flow to the brain and may increase the risk of stroke.
9. Guide treatment such as laser or radiofrequency ablation of abnormal veins.
10. Check the health of a foetus. Blood flow in the umbilical cord, through the placenta, or in the heart and brain of the foetus may be checked. This test can show if the foetus is getting enough oxygen and nutrients.

During Doppler ultrasound, a handheld instrument (transducer) is passed lightly over the skin, above a blood vessel. The transducer sends and receives sound waves that are amplified through a microphone. The sound waves bounce off solid objects, including blood cells. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler Effect). If there is no blood flow, the pitch does not change. Information from the reflected sound waves can be processed by a computer to provide graphs or pictures that represent the flow of blood through the blood vessels. These graphs or pictures can be saved for future review or evaluation.

You may be asked to not use products that contain nicotine (cigarettes, chewing tobacco) for 30 minutes to 2 hours before the test. Nicotine causes blood vessels to constrict and may give false results.

There is normally no discomfort involved with having a Doppler ultrasound test. The gel may feel cold when it is put on your skin unless it is first warmed to body temperature. If your blood pressure is taken during the test, you will feel pressure when the blood pressure cuff is inflated.

Reasons you may not be able to have the test or why the results may not be helpful include:

1. Bones above the area being studied or gas in the intestines.
2. Not being able to remain still during the test.
3. Extreme obesity.
4. Irregular heart rhythms (arrhythmias) or heart disease, which may cause changes in blood flow patterns even though the blood vessels are not abnormal.
5. Having a cold arm or leg. Blood flow through that limb may be slowed.
6. Having an open wound in the area that needs to be viewed.