Understanding How Ultrasounds Work


Ultrasounds are a non-invasive technique used in the medical field to capture images of internal organs of the body including blood vessels, muscles and other soft tissues. A special device is used to emit high-frequency sound waves into the body to reflect against organs and produce an image. The process is similar to echolocation that bats and dolphins use to navigate their path.

Unlike CT scans and x-rays, the sound waves used in ultrasounds are radiation free and are at a frequency that they can’t be heard by humans. This makes ultrasounds incredibly safe for both humans and animals. You can always find out more about their safety on informative online sources like Inside Radiology.

How they Work

Before learning about the imaging process and understanding how ultrasounds work, let us take a look at the machine used to take those images.

Ultrasound Machine

Imagen de falco en Pixabay

If you have never seen one, a basic ultrasound machine consists of a probe or transducer and a central processing unit connected to a monitor to display the images. The device is also attached to a mouse and a keyboard to allow the examiner to take images and a printer to print the images.

While most transducers or probes are commonly used to examine the body from the outside by placing it on the skin, there are specialized ones made for internal evaluation. Used for a clearer and more detailed image, these transducers include:

  • Endovaginal transducer: Used for internal vaginal examination.
  • Endorectal transducer: Used for internal rectal examination.
  • Transoesophageal transducer: Used for oesophageal examination by passing through the throat.

How it Works

An ultrasound scan is usually performed by a sonographer but is evaluated by a doctor, radiologist or another diagnostic expert.

The scan begins by the sonographer applying a gel that helps the transmission of sound waves and then passing the transducer over the area that covers the organs intended for testing. The sonographer than emits sound waves ranging in frequency between 2 to 18 megahertz (MHz).

The sounds emitted from the transducer then bounce back when they hit an organ or other dense structures. The transducer picks up these reflected waves, which are then relayed to the CPU. The machine then measures the distance and intensity of these waves and creates 2-dimensional images that display on the screen.

Uses of Ultrasound

As discussed earlier, ultrasounds are used to take internal, images of the body. It can be used in various clinical settings including obstetrics and gynaecology, cardiology and even cancer detection. However, the main uses include the following:

  • Ob/Gyn:
    • Measuring the size and position of the foetus
    • Determine due date
    • Checking the size, position and condition of the placenta
    • Finding out the sex of the baby
    • Detecting ectopic pregnancy
    • Examining vaginal, uterine, cervix and ovarian health
    • Breast lump examination
    • Others
  • Cardiology
    • ECG is used for examining the health of the cardiac muscles, valves, atriums etc
    • Measuring blood flow through the heart and vessels
    • Checking for blockages, aneurysms, clots etc
  • Urology
    • Checking the urinary tract, bladder or kidney for stones and blockages
    • Detecting prostate cancer
    • Measuring blood flow through the kidney

In addition to the aforementioned uses, ultrasound scans have been developed for diagnosis and biopsy in other medical areas.

Specialist doctors and nurses are required to perform ultrasounds, so if this is something you could see yourself doing, you may want to utilize companies like Day Webster for their recruitment services.

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