Ultrasound imaging uses sound waves to produce pictures of muscles, tendons, ligaments and joints throughout the body. It is used to help diagnose sprains, strains, tears, and other soft tissue conditions. Ultrasound is safe, non-invasive, and does not use ionizing radiation.
This procedure requires little to no special preparation. Leave jewellery at home and wear loose, comfortable clothing. You may be asked to wear a gown.
What is Ultrasound Imaging of the Musculoskeletal System?
Ultrasound is safe and painless, and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography, involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds that bounce back and a computer then uses those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays), thus there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels.
Ultrasound imaging is a non-invasive medical test that helps physicians diagnose and treat medical conditions.
Ultrasound images of the musculoskeletal system provide pictures of muscles, tendons, ligaments, joints, and soft tissues throughout the body.
What are some common uses of the procedure?
Ultrasound images are typically used to help diagnose:
- Tendon tears, or tendinitis of the rotator cuff in the shoulder, Achilles tendon in the ankle and other tendons throughout the body.
- Muscle tears, masses or fluid collections.
- Ligament sprains or tears.
- Inflammation or fluid (effusions) within the bursae and joints.
- Early changes of rheumatoid arthritis.
- Nerve entrapments such as carpal tunnel syndrome.
- Benign and malignant soft tissue tumours.
- Ganglion cysts.
- Foreign bodies in the soft tissues (such as splinters or glass).
- Dislocations of the hip in infants.
- fluid in a painful hip joint in children.
- neck muscle abnormalities in infants with torticollis (neck twisting).
- soft tissue masses (lumps/bumps) in children.
How should I prepare?
You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewellery in the area to be examined.You may be asked to wear a gown during the procedure.
Ultrasound examinations are very sensitive to motion, and an active or crying child can prolong the examination process. To ensure a smooth experience, it often helps to explain the procedure to the child prior to the exam. Bringing books, small toys, music or games can help to distract the child and make the time pass quickly. The ultrasound exam room may have a television. Feel free to ask for your child’s favourite channel.
No other preparation is required.
What does the equipment look like?
Ultrasound scanners consist of a console containing some computer and electronics, a video display screen and a transducer that is used to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached to the scanner by a cord. Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then listens for the returning echoes from the tissues in the body. The principles are like sonar used by boats and submarines.
The ultrasound image is immediately visible on a video display screen that looks like a computer or television monitor. The image is created based on the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the area within the patient that is being examined to the transducer (the device placed on the patient’s skin to send and receive the returning sound waves), as well as the type of body structure and composition of body tissue through which the sound travels. A small amount of gel is put on the skin to allow the sound waves to travel from the transducer to the examined area within the body and then back again. Ultrasound is an excellent modality for some areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound.
How does the procedure work?
Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an object, it bounces back, or echoes. By measuring these echo waves, it is possible to determine how far away the object is as well as the object’s size, shape and consistency (whether the object is solid or filled with fluid).
In medicine, ultrasound is used to detect changes in appearance, size or contour of organs, tissues, and vessels or to detect abnormal masses, such as tumours.
In an ultrasound examination, a transducer both sends the sound waves into the body and receives the echoing waves. When the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids and tissues, the sensitive receiver in the transducer records tiny changes in the sound’s pitch and direction. These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor. One or more frames of the moving pictures are typically captured as still images. Short video loops of the images may also be saved.
How is the procedure performed?
For certain ultrasound examinations of the musculoskeletal system, the patient may be seated on an examination table or a swivel chair. For other ultrasound exams, the patient is positioned lying face-up or face-down on an examination table. The radiologist or sonographer may ask you to move the extremity being examined or may move it for you to evaluate the anatomy and function of the joint, muscle, ligament or tendon.
Most ultrasound studies of infants and children are performed with the child lying on his or her back on the examination table, but other positions may be required.
After you are positioned on the examination table, the radiologist (a physician specifically trained to supervise and interpret radiology examinations) or sonographer will apply a warm water-based gel to the area of the body being studied. The gel will help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin that can block the sound waves from passing into your body. The transducer is placed on the body and moved back and forth over the area of interest until the desired images are captured.
There is usually no discomfort from pressure as the transducer is pressed against the area being examined. However, if scanning is performed over an area of tenderness, you may feel pressure or minor pain from the transducer.
Once the imaging is complete, the clear ultrasound gel will be wiped off your skin. Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain or discolour clothing.
What will I experience during and after the procedure?
Ultrasound examinations are painless and easily tolerated by most patients.
Musculoskeletal ultrasound examination is usually completed within 15 to 30 minutes but may occasionally take longer.
When the examination is complete, you may be asked to dress and wait while the ultrasound images are reviewed.
After an ultrasound examination, you should be able to resume your normal activities immediately.