What is an ultrasound?
An ultrasound is a common imaging technique that employs high frequency sound waves to create images of organs and other internal structures of the body. These images provide valuable information of underlying pathology of the tissues and assists with diagnosis and planning the treatment of a condition. Ultrasound provides a clear view of the organs, tendons, muscles or joints and any associated disorders.
What is an Ultrasound-guided Injection?
An ultrasound-guided injection is a minimally invasive procedure used for:
- Treating various painful musculoskeletal conditions such as tendonitis, bursitis and neuritis
- To perform cyst aspiration
- Tool for guiding the placement of needles for both diagnostic as well as therapeutic purposes
Injection of a pain medication in combination with a local anesthetic directly to the site of injury helps to relieve pain. The advanced imaging of the ultrasound provides high resolution images that enable your physician to precisely locate the injections deep into the target tissue without harming surrounding tissues.
Advantages of Ultrasound-guided Injections
The advantages of ultrasound imaging compared to other imaging techniques include the following:
- No patient exposure to ionizing radiation
- Able to assess tendons, ligaments and muscles under high resolution
- Provides direct visualization of the area being treated
- Ensures accurate placement of the needle to targeted areas
Indications of Ultrasound-guided Injections
The indications for diagnostic ultrasound imaging technique include the following:
- To diagnose conditions such as tendon/ligament tears, inflamed bursa, joint fluid and cysts
- To assess painful pops and snaps that occur during movement
- To deliver diagnostic injections to specific targets including joints and tendon sheaths or bursa
- To help guide needle placement during needle aspirations or injections for patients with challenging anatomical variations or people taking blood-thinning medications
- In aspiration of a ganglion cyst
- To guide needles in percutaneous therapy for the treatment of calcific tendonitis
Ultrasound-guided Injection Technique
The procedure is used for diagnostic as well as therapeutic purposes. Anti-inflammatory medications such as corticosteroids and hyaluronans are the most commonly used medications to relieve pain, inflammation and swelling or to stimulate synovial fluid production to improve lubrication.
Ultrasound-guided injections are commonly used for certain conditions such as osteoarthritis or tendonitis. The administration of the injection to the diseased joint depends upon the condition to be treated. The approach for application of the injection may be anterior, posterior, superior or inferior aspect of the joint.
During an ultrasound-guided injection, the patient will be asked to lie or sit down on a table depending on the site of the injection. A clear water based conducting gel is applied over the skin to assist with transmission of the sound waves. The doctor moves a hand-held probe, called a transducer, over the targeted area. The transducer emits sound waves and detects the rebound echoes from the tissue. Images are created from these sound waves and can be viewed on the video display screen attached to the scanner. The waves provide a clear view of the targeted area and help the doctor locate the correct site for injection.