Ultrasound is a non-invasive procedure that uses sound waves, not radiation, to assess body structures. A technologist applies gel over the area of interest and presses an ultrasound transducer onto the skin. The transducer generates sound waves and detects the echo produced in the body. A computer interprets the echo and provides detailed images for the radiologist.

What is an Ultrasound?

Ultrasound imaging is also called diagnostic sonography. Medical ultrasound is an imaging technique used to create an image of internal structures such as muscles, tendons, joints, and other internal organs.

Ultrasound exams use sound waves with frequencies which are inaudible to humans to create images when the ultrasound pulses echo off internal organs.

Your ultrasound technician may be called a diagnostic sonographer. The difference between the terms is simple: ultrasound is the process of using equipment to take sonograms (images), while sonography is the use of these images for diagnostic purposes.

For you as a patient, the human touch of your sonographer can dramatically impact how you experience ultrasounds. That is why Insight Medical Imaging travels across the country, from British Columbia to Nova Scotia, to recruit the best diagnostic medical sonographers to perform our ultrasound exams.

Common Procedures

The most familiar form of ultrasound imaging is an obstetric ultrasound procedure for pregnant women. While many other evaluations use ultrasound, obstetric imaging is so well-known, it is top of mind in almost every patient.

Ultrasound is also commonly used to examine the:

What To Expect During Your Ultrasound Procedure

  • When examining certain body parts, we may ask you to change into a gown to allow easier access. Sometimes our technologists can rearrange your clothing to expose a body part so you do not have to change.
  • The technologist will apply a warm, hypoallergenic ultrasound gel and move the transducer (probe) around the area of interest with moderate pressure to obtain images.
  • This pressure should not cause any pain. Please inform your technologist of any discomfort.
  • The technologist may ask you to change positions – on your side, sitting, or standing – so they can obtain the best possible images.
  • After we capture all necessary images, one of our radiologists will review the results and send a detailed report to your doctor. We try our best to send the report as soon as possible, usually within one business day.

What Substance Is Put on Your Body During the Procedure?

Before your sonographer begins the ultrasound scan, they will apply a warm lubricating substance to the area of interest. This substance is known as ultrasound transmission gel.

During your exam, the ultrasound probe is pushed against this gel to help capture images. The gel is hypoallergenic, non-irritating, and non-sensitizing, so you are unlikely to have a reaction.

The way in which ultrasound transmission gel operates is by reducing the acoustic impedance and conducting the sound waves between the probe and your body. Ultimately, it creates a bridge between the probe and your tissue, allowing for clear transmission.

Sound Waves vs. Radiation

Most forms of medical imaging lead to some level of radiation exposure, either through injection or external contact.

Ultrasound scans differ because they use high-frequency sound waves to generate images that are then used for diagnosis.

If you are planning on having children you must be completely transparent with your doctor before scheduling an imaging exam, as unnecessary radiation exposure during pregnancy or while breastfeeding can have a lifelong impact.

If your physician can avoid exposing you to unnecessary radiation and still reach a conclusive diagnosis, they will likely refer you for an alternative form of imaging, such as ultrasound or magnetic resonance (MRI).

Ultrasound Limitations from Tissue Composition

The three factors that significantly impact ultrasound effectiveness and visibility are:

  • Density – Sound waves cannot pass through hard, dense objects, such as bone or calcifications.
  • Gas – Gas in the gastrointestinal (GI) system and bowel is a strong sound-wave reflector that negatively impacts transmission and can create reverberation artifacts in diagnostic imaging.
  • Depth – The deeper something is inside your body, the less likely ultrasound waves will penetrate the tissue with the same efficiency.

How to Prepare for your Procedure

Depending on the type of ultrasound procedure you are scheduled for will determine how you should prepare for your ultrasound exam. For pelvic ultrasounds and obstetric ultrasounds, we instruct our patients to consume 32 oz. of water before the exam.

We require our patients to drink four (8 oz.) glasses of water and finish all of them an hour before the ultrasound exam starts. We also ask that you do not go to the washroom until the exam is over or until your sonographer confirms you are able to.

For abdominal ultrasound procedures, we ask that you do not eat or drink anything for six to eight hours before your test. However, your doctor may request a combined abdominal and pelvic ultrasound exam. In this case, you must fast as well as have a full bladder.

Please consult with your doctor or sonographer for more information on the preparation needed for your ultrasound or see our Exam Preparation page.

Why is Drinking Water Important?

Some ultrasound exams require special preparation, such as drinking water before the appointment. While this may seem like an odd request, it is a very important detail to ensure your ultrasound procedure goes as well as possible.

We instruct patients to drink four (8oz) glasses of water, finishing all four glasses 60 minutes before their appointment, and not to urinate. Drinking this amount of water forces your urinary bladder to expand, pressing the uterus up and moving other organs, such as the bowel, out of the way.

If you do not drink the correct amount of water or you urinate before the ultrasound scan, your bladder will shrink and contract, making it difficult to examine the walls. The water inside your expanded bladder also allows the high-frequency sound waves to penetrate deeper into your abdomen, beyond the rigid, bony pelvic structure.

Essentially, the water moves your internal organs into a better position and provides a clear window for higher-quality imaging.

Other ultrasound exams require that you fast (do not eat) for a certain period before your scan. Fasting ensures there is no digesting matter inside your stomach at the time of your scan. Digesting food in your stomach is dense, so sound waves have a harder time penetrating and creating a clear image.

Talk to your diagnostic sonographer or physician for more information about preparing for your ultrasound procedure.

Discomfort from the Exam Preparation

We understand it can be difficult and uncomfortable to fast or to drink a large volume of water without relief. That’s why we do our best to get you in on time for your ultrasound exam and, if possible, perform parts of the exam that require a full bladder first.

If you are in an uncomfortable amount of pain from drinking water, tell our receptionists or sonographers. Sometimes you can release a little urine before your exam after consulting with our staff.

Other times, your sonographer will try to capture specific photos at the beginning of the appointment and then allow you to go to the washroom for a little relief before finishing the rest of the ultrasound exam.

If you have experienced discomfort or pain from a full bladder in the past, there is a high likelihood it was from drinking water too early or continuing to drink right up until your exam. We suggest that you drink all four (8oz) glasses of water in a 30-minute window.

This window should start 90 minutes before your appointment (so you finish drinking 60 minutes before your exam). This has proven to be the best compromise for patient comfort while still allowing us to capture high-quality images during your ultrasound procedure.


How long will the Procedure take?

Although largely dependent on the type of ultrasound procedure you are receiving, an average ultrasound exam lasts approximately 30 minutes. Due to possible delays based on the complexity of the exam you are undergoing, we ask that you arrive at least 15 minutes prior to the procedure.

What happens after my Procedure?

After your ultrasound exam is complete, you may resume your normal activities and diet unless your doctor or sonography instructs you otherwise. For almost all ultrasound procedures, there are no after-effects or debilitating physical repercussions.

For obstetric ultrasound exams, we will be able to print some ultrasound images and can also send digital photos to your cell phone or email for maximum convenience. However, the results of your ultrasound will be reviewed first by a radiologist and then a detailed report will be sent to your doctor, usually within one business day.

Please consult with your doctor to receive the results of the ultrasound procedure.

Internal Ultrasound Procedure

Certain ultrasound exams for women may require additional imaging in the form of an internal exam. These ultrasound scans are performed transvaginally and give our radiologists more detailed images for diagnosis. Typically, we conduct internal procedures on women who have a pelvic, renal, obstetric or combined abdomen/pelvic appointment.

To make this portion of the exam more comfortable, patients can request female sonographers at the time of booking. It is important to understand that because of the volume of exams and staffing limitations, we cannot always meet this request.

However, if a male sonographer must perform your internal ultrasound, we ensure that a female colleague is in the room with you during the scan to chaperon.

Biopsy Needle Guidance

Ultrasound imaging is highly useful for visualizing musculoskeletal anatomy and guiding interventional radiology procedures, such as biopsy, in real time.

Conventional guidance with fluoroscopy or CT imaging relies on short exposure to ionizing radiation. Ultrasound guidance uses sound waves instead of ionizing radiation.

Benefits of Ultrasound Guidance over Traditional Guidance

Ultrasound guidance offers the following benefits:

  • Zero exposure to ionizing radiation
  • Longer insertion window
  • Improved needle placement accuracy
  • Reduced risk of injury to neighbouring anatomy
  • Real-time confirmation of procedural success

Insight Medical Imaging uses ultrasound guidance for many intervention procedures, such as core and aspiration biopsy and wire localization, as well as pain management injections. Learn more about ultrasound guided biopsy, including preparation, how the exam is commonly performed, what you can expect after the injection, and more.

Insight Clinics Offering Ultrasound Exams

We have 12 locations in Alberta that offer ultrasound exams and other medical procedures. For your ultrasound examination needs, visit our locations at Castledowns, Heritage, Hermitage, Lendrum, Meadowlark Diagnostic, Millwoods, Oliver Square, West End, Leduc, Sherwood Park, Spruce Grove, or Fort McMurray. Find a location in your city to complete your ultrasound.

Exam Preparation

Planning your next appointment? Learn more about ultrasound exam preparation and find the clinic most convenient for you.

Ultrasound Scans:

Abdominal Ultrasound

Echocardiogram - Heart Ultrasound

Musculoskeletal - MSK Ultrasound

Obstetric Ultrasound

Pelvic Ultrasound

Renal Ultrasound

Soft Tissue Mass Ultrasound

Testicular Ultrasound

Thyroid Ultrasound

Vascular Ultrasound