What Is Ultrasound?

Ultrasound is a noninvasive imaging technique that makes use of high-frequency sound waves to capture images of organs and measure distances inside the body. The procedure can capture movements inside an organ, such as movements of foetus in mother’s womb and is used by physicians for an exact diagnosis and evaluation of health conditions.

Ultrasound uses a transducer that produces high-frequency sound waves, which reflect to produce an image of the organ or foetus on a computer screen. It can be viewed in real time or printed as a photograph.

Medical ultrasound can be used for diagnostic and therapeutic purposes:

  • Diagnostic ultrasounds: Diagnostic ultrasounds are primarily used to diagnose or evaluate a condition and are divided into two types, anatomic and functional:
    • Anatomic ultrasounds: These are used for imaging organs such as the uterus, abdominal organs, skin, blood vessels, different glands and breasts.
    • Functional ultrasounds: These are used to visualise changes in the structure or function of an organ. E.g., Doppler and colour Doppler techniques are used to visualise blood flow in heart and to determine whether the plaque accumulated inside blood vessels is affecting blood flow to the brain.
  • Therapeutic ultrasounds: This includes procedures which use ultrasound waves to heat, destroy or break up tissue. E.g., high-intensity focused ultrasound, a type of therapeutic ultrasound, is being tested for its use in breaking up clots in blood vessels, closing wounds, stopping bleeding and other purposes.
  1. What do Ultrasound results indicate?
  2. How is Ultrasound performed?
  3. How do you prepare for an Ultrasound?
  4. Why is Ultrasound performed?

Normal results: Normal results in ultrasound imaging suggest that the organ under investigation appears to be in a healthy state in the images obtained.

Abnormal results:

Abnormal images are captured when some sort of structural or functional anomalies are found in an organ. The following things can be identified in an ultrasound image, depending on the tissue under observation:

Ultrasound imaging provides basic information about abnormalities present in an organ. The findings can be confirmatory, or further investigations may be needed using other techniques, such as a computerised tomography scan, magnetic resonance imaging or a biochemical investigation, to confirm the diagnosis.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is provided from a purely educational perspective and is in no way a substitute for medical advice from a qualified doctor.

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An ultrasound examination generally takes 30 to 60 minutes depending on the type of ultrasound advised. Patient is made to lie on a table, and a gel is applied over the area under investigation. This ensures smooth gliding of the transducer on the skin.

A handheld transducer will be moved over that area for which imaging is carried out. As it moves, it sends signals which are recorded by a radiologist and an assistant on the computer screen.

The report is handed over to the patient within a few minutes of the imaging.

Ultrasound imaging is regarded as a safe technique, although the procedure involves an increase in tissue temperature and some mechanical changes due to sound waves and pressure exerted. Hence, in case of repeated exposures to ultrasound, it is advisable that the radiologists weigh the risk involved.

The test is simple and does not require any special preparation. For hospitalised and weak patients, portable bedside ultrasound units are available. Ambulatory patients can walk into radiology centres for undergoing an ultrasound. Some patients may be advised to drink water and avoid urinating before an ultrasound to ensure that the bladder is full. This helps get better and more clear images. If a patient has a biopsy scheduled in the morning, he or she is advised not to drink water or have food after midnight for the ultrasound examination.

One will be given loose clothing, such as a gown, to be worn during the study and will be advised to leave any jewellery out of the room during imaging. Patient is expected to share allergy details with the physician and the radiologist before undergoing ultrasound imaging.

A diagnostic ultrasound examination provides images of organs, and it can be used as a tool to diagnose any structural or functional abnormalities in body organs. The commonest use of an ultrasound examination is during pregnancy to study foetal development. Several other organs, such as thyroid gland; breast; and abdominal organs, such as liver, intestine, stomach, gallbladder, kidneys and spleen, can be examined for abnormalities using ultrasound imaging. There are several other key areas where ultrasound helps with an accurate diagnosis of the condition. Following are the conditions where ultrasound imaging is advised by a physician.

  • Pregnancy
  • Ectopic pregnancies or menstrual disorders
  • Trauma and surgical emergencies, such as injury to the pneumothorax or other organs
  • Blockages in blood vessels of heart (using Doppler ultrasound)
  • Deep venous thrombosis
  • Pulmonary embolism
  • Detection of renal calculi
  • Guidance for needle biopsies
  • Examination and biopsy of the breast


  1. Sudheer Gokhale. Ultrasound characterization of breast masses. Indian J Radiol Imaging. 2009;19(3):242–247.
  2. Sung Jae Kwon and Mok Kun Jeong. Advances in ultrasound elasticity imaging. Biomed Eng Lett. 2017;7(2):71–79.
  3. National Institute of Biomedical Imaging and Bio engineering [internet]. Bethesda (MD); US Department of Health and Human Services; Ultrasound
  4. Rebecca Smith Bindmann et al. Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study.. JAMA Intern Med. 2013;173(19):1788–1796.
  5. US Food and Drug Administration (FDA) [internet]; Ultrasound Imaging
  6. Andrzej Wozniak and Slavomir Wozniak.Ultrasonography of uterine. leiomyomas. Prz Menopauzalny. 2017;16(4):113–117.
  7. Jongbum Seo and Young-sun Kim. Ultrasound imaging and beyond: recent advances in medical ultrasound. Biomed Eng Lett. 2017;7(2):57–58.
  8. Better health channel. Department of Health and Human Services [internet]. State government of Victoria; Ultrasound scan
  9. Department of Radiology and Biomedical Imaging [internet]: University of California, San Francisco; Prepare for an Ultrasound (Sonography)
  10. Stefannie Sippel. Review article: Use of ultrasound in the developing world. Int J Emerg Med. 2011;4:72.
  11. Wayne Brisbane et al. An overview of kidney stone imaging techniques. Nat Rev Urol. 2016;13(11):654-662.
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