Tests and diagnosis

By Mayo Clinic Staff

During the physical exam, your doctor will check your joints for swelling, redness and warmth. He or she will also want to see how well you can move your joints. Depending on the type of arthritis suspected, your doctor may suggest some of the following tests.

Laboratory tests

The analysis of different types of body fluids can help pinpoint the type of arthritis you may have. Fluids commonly analyzed include blood, urine and joint fluid. To obtain a sample of your joint fluid, your doctor will cleanse and numb the area before inserting a needle in your joint space to withdraw some fluid (aspiration).

Imaging

These types of tests can detect problems within your joint that may be causing your symptoms. Examples include:

  • X-rays. Using low levels of radiation to visualize bone, X-rays can show cartilage loss, bone damage and bone spurs. X-rays may not reveal early arthritic damage, but they are often used to track progression of the disease.
  • Computerized tomography (CT). CT scanners take X-rays from many different angles and combine the information to create cross-sectional views of internal structures. CTs can visualize both bone and the surrounding soft tissues.
  • Magnetic resonance imaging (MRI). Combining radio waves with a strong magnetic field, MRI can produce more-detailed cross-sectional images of soft tissues such as cartilage, tendons and ligaments.
  • Ultrasound. This technology uses high-frequency sound waves to image soft tissues, cartilage and fluid-containing structures such as bursae. Ultrasound also is used to guide needle placement for joint aspirations and injections.

Arthroscopy

In some cases, your doctor may look for damage in your joint by inserting a small, flexible tube — called an arthroscope — through an incision near your joint. The arthroscope transmits images from inside the joint to a video screen.

Jan. 22, 2013