“Ultrasonography” or more widely known as “Medical Ultrasound” is a diagnostic technique which uses high frequency ultrasound waves in order to produce images of internal body structures such as muscles, tendons, vessels and joints. The motive is to find the source of a disease and then take measure s to treat the same.

How does “Ultrasonography work ?

In order to get the ultrasound image, an equipment called “Transducer” is used which transforms electric current into sound waves that are induced into various tissues of the body. These sound waves are usually absorbed or are bounced back as crystals in the head of the Transducer.

E.g Sound waves easily permeate through areas which are empty or fluid filled such as the bladder, various blood vessels etc. These areas are visibly dark on the screen. Portions that are filled with tissue , somewhat allow penetration and refraction of these sound waves to some extent and thus give grayish white image. Extremely hard structures such as bones give a bright white image since the ultrasound waves completely rebound to the transducer.

A commonly used phenomenon during pregnancy, Ultrasonography allows Doctors to view the image of a women’s womb in order to assess the overall development of the baby, detect abnormalities if any and gender of the baby if required. It can measure the cervix and ovaries as well.

Procedure

In case an abdomen is to be examined, the patient might be asked not to eat or drink for a number of hours before the test.

Once everything is set, the technician applies a thick gel on the skin over the area that has to examined , in order to ensure effective sound transmission . The Transducer is carefully placed on the skin and gently moved over the area that has to be examined.

Depending on the body part that needs to be evaluated, the technician at times, inserts the transducer into that organ. E.g. in order to get a better image of the uterus and ovaries one needs to insert the device into the vagina or into the anus to get a precise image of the prostate gland.

Advantages / Uses of Ultrasonography

A boon to the field of Medicine, Ultrasonography has a number of uses. Some of them are listed below:

• The images are captured rapidly so as to show the movement of internal organs and structures in the body on real time basis. E.g. even the motion of the beating heart of a fetus can be seen.
• It can be effectively used to view images of internal organs in the chest, pelvis and abdomen. Since sound waves can be blocked by gas and by bone , ultrasonography of internal organs can be done only by specially trained professionals known as ”Sonographers”.
• Ultrasound technology can also be used to find out growth of foreign objects that are very close to the internal body parts such as the ones in breasts, testes, lymph nodes, limbs and the thyroid gland.
• Ultrasonography device is portable and can be easily brought to the bedside for the convenience of the patient.
• Morever, it is affordable and does not use harmful radiation.

Commonly Used To Diagnoise The Following Disease

• Pregnancy : A common usage of Ultrasonography, is to observe the growth and development of a foetus along with detection of anomalies of the placenta.
• Heart ( Echocardipgraphy) : It detects anomalies in the heart beats, structural abnormalities such as enlargement of heart’s walls or chambers, defective heart valve etc.
• Gall bladder and biliary tract : In order to detect gall bladder stones and blockage in the bile duct.
• Blood vessels : To detect narrowed and dilated blood vessels.
• Urinary tract : Untrasonography can be effectively used to differentiate benign cysts from the malignant ones( Cancer causing) or to detect structural anomalies in the kidney, uterus or the bladder.
• Liver spleen and pancreas : Tumors and other disorders can be detected well in time.
• Female reproductive organs : The abnormalities in uterus, ovaries and fallopian tubes can be detected on time through Sonography and suitably treated .

Disadvantages of Ultrasonography

The super successful and useful Ultrasonography is not devoid of loopholes. To list a few:

• Discomfort: The insertion of the device into the body might cause discomfort and be the cause of inconvenience. At times, incorrect insertion the Transducer might cause damage to the tissue resulting in bleeding or infection.
• Since gas and bone block ultrasonography, using it to obtain images of organs behind bone or gas becomes very difficult and gives inaccurate results.
• Moreover, it can be performed only by skilled Technicians/Sonographers who are exclusively trained for the same , thereby adding additional cost to the diagnostic center.

Variations of Ultrasonography : Ultrasound details can be displayed in a several possible ways :

• A-Mode : Information is displayed as spikes on a graph.
• B-mode : Images can be viewed as a 2-dimensional anatomic images (used at the time of pregnancy)
• M-Mode : Images are displayed continuously as waves to show moving structures.

The most practiced one is the “ B-Mode” Ultrasonography

Doppler Ultrasonography

It is basically used to evaluate the moving objects, such as the RBC in the blood and can be used to evaluate if the heart is functioning well or not . It can also be used to detect blocked blood vessels, narrowed arteries etc.

Spectral Doppler Ultrasonography

Over here , the blood flow information is shown as a graph and can be very helpful in determining as to how much of a blood vessel is blocked.

Duplex Doppler Ultrasonography

It combines spectral and b-mode Ultrasonography .

Color Doppler Ultrasonography

This form is used to assess the risk of stroke as it helps the doctors to identify blockage of arteries in the neck and head.