What is Ultrasound (Sonography)?

Ultrasound (US) is a diagnostic medical imaging technique that uses inaudible, high frequency sound waves to visualize muscles, tendons, and internal organs in the body (excluding the skull and lungs) and provides a clearer picture (as a sonogram) of soft tissues than X-ray images. Sound wave are emitted by an HDI Technologist over the body part being examined using a handheld device called a transducer. The waves bounce off and/or pass through the body’s organs and tissues and return a signal back to the transducer. The signals are relayed to a special computer that converts that information into a real-time image.

Doppler US is a special ultrasound technique that is used to evaluate blood flow speed and direction through arteries and veins in the body (excluding the skull) and inside body organs. Sometimes, general ultrasound imaging and Doppler US are used together in tests to evaluate presence of disease before symptoms occur, as with Peripheral Vascular Disease and Carotid Artery Screenings.

Ultrasound has been used by sonographers to image the human body for more than 50 years and has become one of the most widely used diagnostic tools in modern medicine.

Ultrasound is commonly used for evaluating:

  • A fetus during pregnancy
  • Internal tissues and organs
  • Organ damage after an illness
  • Symptoms of pain, swelling infection
  • Breast masses, uterus and ovaries
  • Tendons and muscle tears
  • Blood flow and vessel or arterial narrowings
  • Heart valve function
  • Pathological lesions and cancers
  • Needle biopsies

Ultrasound and radiation safety

A standard diagnostic ultrasound has no known harmful effects on humans. An ultrasound exam uses no ionizing radiation or contrast agents.


Continue taking your current medications as normal unless specified by your physician.

Food and drink

If you are having an abdominal ultrasound, you should not eat or drink (other than water) after midnight prior to your test. For OB, Pelvic, and Renal (kidney) ultrasound exams, you should drink at least 24 ounces of water 1 before your exam without emptying your bladder. A full bladder will help enhance the clarity of the sonogram. For all other ultrasound exams such as pelvic, thyroid, scrotal, and vascular studies, no advance preparation is required.

When to arrive

Please arrive at High Desert Imaging 15 minutes before your exam appointment.

What to wear

Wear comfortable clothing, preferably clothes with no zipper or buttons, like sweats. You may also be asked to remove jewelry, eyeglasses and any metal objects or clothing that might interfere with the images. Gowns are available if needed.


Ultrasound exams are painless, quick, and easily tolerated by most patients. The procedure will require you to lie on an exam table adjacent to the ultrasound scanner as the technologist performs the procedure and you’ll typically be able to watch the images on the computer monitor appear in real time as the transducer move over the targeted area. The gel applied to the area to be imaged may feel a bit cold and you might experience varying degrees of discomfort or pressure as the transducer is slowly guided across the abdomen, especially if your bladder is full.

For women undergoing a transvaginal ultrasound exam, a small, specially designed transducer may be inserted into the vagina by yourself or your HDI Technologist which may cause some pressure and/or discomfort. It will be necessary to move the transducer to capture the desired images during the procedure and you may request the exam to be stopped at any time if you are experiencing significant discomfort.


During your procedure, your HDI Ultrasound Technologist will situate you in a comfortable position on the exam table and apply a clear gel to the skin over the area being examined. The gel maximizes contact between the transducer and the skin, thereby producing high quality images. The transducer will then be moved slowly over the targeted area as it obtains the diagnostic data.

Length of scan

Depending on the type of test you are having, an ultrasound exam averages between 10-30 minutes in duration. Transvaginal exams take approximately 15-20 minutes to perform.

After your ultrasound exam

After your exam, you may resume your normal activities, diet, and medications immediately unless instructed otherwise by your HDI Technologist or doctor.

Scan results 

We pride ourselves on delivering superior studies and rapid exam results. Diagnostic exams are typically read within 24 hours with results sent to your primary care physician who will go over them with you in detail. We’ll also provide you with a DVD copy of your exam images.

If you have additional questions about our ultrasound procedures, please use our online contact form or call us at 775.621.5800.