What is the difference between an X-ray, MRI and ultrasound?
All three diagnostic techniques are complimentary in the assessment of arthritis. X-rays help to examine gross structure of the bones, joint alignment and changes in the joint space. MRI (magnetic resonance imaging) is useful in evaluation of bones, joints and soft tissues as well as nerves (e.g, spinal cord and spinal nerves). Both X-ray and MRI-based approaches are mostly used to define normal versus abnormal anatomy. The ultrasound is utilized to define abnormalities in ligaments, tendons and muscles (the sound waves do not penetrate inside of the bones). It is also used to study real-time joint movement and changes in blood flow in the joints and soft tissues. The ultrasound is the least invasive technique and can be easily performed at the bedside. It is also helpful in the guiding of various procedures including joint aspirations and injections.
