Why Is an Ultrasound Done?
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Ultrasound - Indications, Types, and Method

Published on Sep 05, 2022 and last reviewed on Aug 25, 2023   -  4 min read


Ultrasound is also called sonography or diagnostic medical sonography. Read below to know more.


It is an imaging method that uses high-frequency sound waves to produce images of structures within the body. The images can provide information for diagnosing and treating various diseases and conditions. Ultrasound is a painless procedure. However, mild discomfort is felt as the sonographer guides the transducer over the body. A typical ultrasound exam takes from 30 minutes to an hour.

What Are the Types of Ultrasound?

  • Transesophageal Echocardiogram: A transducer inserted into your esophagus obtains heart images. It is usually done while you are sedated.

  • Transrectal Ultrasound: This test creates prostate images by placing a special transducer into the rectum.

  • Transvaginal Ultrasound: A transducer is inserted inside the vagina to quickly look at the uterus and ovaries.

Other names are sonogram, ultrasonography, pregnancy sonography, fetal ultrasound, obstetric ultrasound, diagnostic medical sonography, and diagnostic medical ultrasound.

What Are the Common Uses of Ultrasound Procedures?

Doctors use ultrasound to evaluate:

  • Pain.

  • Swelling.

  • Infection.

Ultrasound helps in examining many of the body's internal organs. Some of them are;

What Is Ultrasound Used For?

An ultrasound can be used for various purposes, depending on the type of ultrasound.

A pregnancy ultrasound is done to check the health of an unborn baby. It is used to:

  • Confirm pregnancy.

  • Limiting the size and position of the unborn.

  • Check to see if you are pregnant.

  • Estimate how long you are pregnant.

  • Checking the baby for any defects.

  • Check for congenital disabilities in the brain, spinal cord, heart, or any part of the body.

  • Check the amount of amniotic fluid.

  • Amniotic fluid is a transparent liquid that surrounds the fetus. It protects the baby from the outside environment. It also helps in lung development and bone growth.

In women, diagnostic ultrasound may be used for:

  • Look at a breast lump.

  • Help to find the cause of pelvic pain.

  • Help to find the cause of abnormal menstrual bleeding.

  • Help to diagnose infertility.

  • To check to monitor infertility treatments.

If you are pregnant, you would need an ultrasound. There is no radiation in the test. It is a safe way of checking the health of the fetus. You may need a diagnostic ultrasound if you have symptoms in specific organs and tissues. They include the heart, kidneys, thyroid, gallbladder, and female reproductive system. You may also need an ultrasound if you are getting a biopsy. The ultrasound helps your doctor to provide a clear image of the area that is being tested.

Ultrasound is also used to:

  • Guide procedures like needle biopsies, in which needles remove the cells from an abnormal area for testing.

  • Image of the breasts and guide biopsy of breast cancer.

  • Diagnose various heart conditions, including valve problems and congestive heart failure, and assess the damage to the heart.

Doppler ultrasound helps the doctor to evaluate:

  • Blocks blood flow (such as clots).

  • Narrow the vessels.

  • Tumors and congenital vascular abnormalities.

  • Decreased or absent blood flow to various organs.

  • Increased blood flow.

What Happens in Ultrasound?

An ultrasound usually includes the following:

  • You will be lying on a table, exposing the area to be checked.

  • A medical provider will spread a special gel on the skin over that area to be revealed.

  • The provider will move a stick-like device, called a transducer, over the surface.

  • The device gives sound waves to the body. These waves are high-pitched and cannot be heared.

  • The waves get recorded and turned into images on the computer by a software.

  • You will be able to view the photos during the scan. It mostly happens during a pregnancy ultrasound.

  • The tests are about 30 to 60 minutes long.

The transducer is inserted inside the vagina during the early stage of pregnancy.

What Is the Preparation for the Ultrasound Scan?

The preparations depend on which type of ultrasound has been done. For ultrasounds of the abdominal area, you may need to fill up your bladder with water before the scan. Some types of ultrasounds require no preparation at all. Your physician will advise if you need anything to prepare for your ultrasound.

Are There Any Risks?

Ultrasound does not have any risk. They are radiation-free scan methods to check all the internal organs.

What Do the Results Mean?

If your pregnancy ultrasound results were as expected, it doesn't guarantee you'll have a healthy baby. No tests can predict that.

But expected results may mean:

  • Your baby is growing at an average speed.

  • You have a good amount of amniotic fluid.

  • No congenital disabilities were found, though not all congenital disabilities will show up on an ultrasound.

If your pregnancy ultrasound results were not expected, it doesn't always mean your baby has severe health problems. If you had a diagnostic ultrasound, the meaning of your results would depend on which part of the body was being looked at.


Ultrasound is a diagnostic method used to determine abnormality in the human body. This is especially important for pregnant women to check the unborn child's health status. Therefore making it a radiation-free scan procedure.

Frequently Asked Questions


Why Do We Do Ultrasound Examinations?

Ultrasound examination is used for multiple reasons, including:
- To view the uterus and the ovaries and monitor the growth and development of the fetus.
- To do a cardiac, urological, gynecological, cerebrovascular, and abdominal examination to detect diseases, lumps, stones, and cancer.
- To guide a needle for biopsy or tumor treatment.
- To capture images of tissues and organs.
- Helps in evaluating metabolic bone diseases.


What Are the Benefits of Ultrasound Over Other Imaging Methods?

Ultrasound is widely available and has the following advantages
- Painless and easy to use. 
- It is usually quick and less expensive.
- A noninvasive procedure and does not use radiation.
- Gives a clear picture of the soft tissues.
- Safe to be used during pregnancy to provide information on the developing baby.


How Is Ultrasound Done?

Ultrasound requires little preparation. The doctor guides you on how to prepare, including whether to eat or drink beforehand.
- You may need to change into a gown and lie down on a table with the section of the body exposed for the test.
- The ultrasound technician applies a lubricating gel to the skin and rubs a hand device called a transducer on the skin. This sends high-frequency sound waves through the body that echo when they hit an organ or bone. For example, you may be asked to be still or hold your breath for a few seconds. This creates clear pictures of the body.
- The echoes reflect a picture into the computer, which can be interpreted by the doctor.
- After the procedure, the gel is cleaned. The whole procedure lasts not more than 30 minutes.


When Do I Get My Ultrasound Results?

Ultrasound is also called sonography or diagnostic medical sonography. It is an imaging method that uses high-frequency sound waves to produce images of structures within the body. You may get the results of your ultrasound, such as prenatal, soon after the scan is performed. However, in other cases, a radiologist may be required to analyze the images and make a report to be sent to the referring doctor.


How Do I Prepare for an Ultrasound?

The preparation for the ultrasound depends on the type of ultrasound to be performed. You may need to follow certain instructions.
  - Drink lots of water and avoid going to the toilet until the scan is over.
  - Avoid eating for several hours before the scan, especially before a scan of the digestive system.
  - In case you need to take your medicine, take it with little water.


Why Do You Need To Have a Full Bladder Before an Ultrasound?

Ultrasound is a painless procedure. Sound waves move through tissues and different mediums, such as fluid and air. A full bladder creates a reservoir of fluid and enhances the movement of sound waves through the abdominal cavity. This gives a clearer picture of the various structures that are to be observed.


Can Ultrasound Be Used To Detect Infections?

Ultrasound is frequently used to evaluate skin and soft tissue infections. The images can provide information for diagnosing and treating various diseases and conditions. In addition, it helps to detect pathophysiological changes inside the body, such as cysts, tumors, obstructions, and fluid collection, in various parts of the body.


Why Should an Ultrasound Be Done After a CT Scan?

Ultrasound of the abdomen or pelvis may be ordered after a negative CT for further evaluation, especially in examining internal organs. For example, an ultrasound provides an improved anatomical detail of the pelvic structures and improves diagnostic accuracy, especially when CT reveals an abnormal pelvic finding such as ovarian torsion or a cyst.


Is CT Scan Better Than Than Ultrasound?

Ct scan and ultrasound are reliable for detecting pathophysiological changes in the body and are widely used imaging technologies. Ultrasounds are easier and comparatively cheaper than CT scans and pose less risk to the patients. However, CT scans can provide more detailed images of certain body areas such as soft tissues, blood vessels, or bony structures.

Last reviewed at:
25 Aug 2023  -  4 min read




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