Tests and diagnosis

By Mayo Clinic Staff

Doctors often can make a diagnosis of knee bursitis during the physical exam. Tests to rule out other problems or to check for infection are sometimes necessary.

Imaging tests

To help rule out injuries that may cause signs and symptoms similar to those of bursitis, your doctor may order one of more of the following imaging tests:

  • X-ray. While they can't visualize bursae, X-rays may be useful in revealing a bone fracture, tumor or arthritis.
  • Magnetic resonance imaging (MRI). MRIs use radio waves and a strong magnetic field to produce detailed images of structures within your body. This technology is particularly good at visualizing soft tissues, such as bursae.
  • Ultrasound. Using sound waves to produce images in real time, ultrasound can help your doctor better visualize swelling in the affected bursa. In some instances, your doctor may also use ultrasound to place a needle into the affected bursa to drain fluid and relieve symptoms.


If your doctor suspects that you have an infection or gout in the bursa, he or she may obtain a sample of the bursa fluid for testing by inserting a needle into the affected area and draining some of the fluid.

May. 03, 2011