- Radiography (x-ray of bones
- Multidetector CT
- Diagnostic ultrasound of joint or bursa
- Arthrography, joint injection & joint aspiration
- CT Arthrogram
- DEXA (bone densitometry)
- MR Arthrogram
- Fluoroscopic or ultrasound guided joint or bursal injections
Imaging of the musculoskeletal (MSK) system encompasses a wide array of problems for patients and necessitates a diverse array of tests to help with diagnosis as well as provide possible treatment options.
The baseline study for MSK radiology is an x-ray (radiography) of the involved bone or joint. Often, the underlying problem can be seen and if not, can help determine the next appropriate test needed. Common ailments frequently seen with radiographs include fractures and osteoarthritis.
Computed tomography (CT) is used for a variety of reasons in MSK imaging. Many orthopedic pre-operative protocols use programmed CT imaging prior to joint replacements. Additionally, complex fractures can be 3D rendered by the radiologist to provide a better layout for the surgeon prior to surgery.
For imaging of muscles, MRI is the workhorse modality. MRI is common to evaluate for ailments of the joints, such as meniscal tears in the knee or rotator cuff tears in the shoulder. Evaluation of muscular strains is easily performed with MRI. Evaluation for infections of the bones is also preferred using MRI.
Ultrasound is an alternative to MRI examination in certain circumstances. Sometimes, patients may have implants/hardware that are not compatible with MRI for safety purposes. This necessitates an alternative imaging modality, and ultrasound is appropriate for certain conditions. Specifically, ultrasound examination of the shoulder for rotator cuff tear or evaluation of a painful lump in the arm or leg are common reasons for ultrasound.
In order to evaluate some soft tissue structures in the joints (such as the labrum in the shoulder or hip), arthrography is performed. Arthrography is the injection of contrast material into the joint, which can be further imaged with CT or MRI. This procedure is performed by the radiologist, usually using fluoroscopy (real time x-ray). The most common joints to have arthrography performed are the shoulders and hips, however, arthrograms of the wrist, elbows, knees and ankles are also performed when appropriate. The procedure entails an injection to the affected joint with subsequent CT or MRI examination to follow.
Joint aspiration and injections are also routinely performed. These are generally performed using fluoroscopic or ultrasound guidance. Often, if the referring physician has concern for infection in a joint, a joint aspiration can be performed with any aspirated fluid sent to the pathology/cytology laboratory for analysis. Similarly, if there is concern for an inflammatory joint disease (such as gout, rheumatoid arthritis or psoriatic arthritis), fluid can be sent to the laboratory for analysis and diagnosis.
Radiologists also perform therapeutic joint injections. Patients who have degenerative arthritis may benefit from steroid and anesthetic injections into the joints. These are usually performed using fluoroscopy or ultrasound. Common injections include the hips and shoulders; however, most joints can be treated, including within the feet and ankles.