What is an arthrogram?
An arthrogram is an imaging study that’s designed to examine and evaluate your joints. The term “arthrogram” actually refers to the image made during the procedure, which is called arthrography. Arthrography uses a special contrast dye that is injected directly into your joint to highlight areas of a joint so they’re more visible to the radiologist and your doctor. Most arthrograms use X-rays or fluoroscopy, a kind of "moving" X-ray. In most cases the joint injection is followed by computed tomography (CT) scanning or magnetic resonance imaging (MRI).
How does arthrography work?
Most arthrogram studies use fluoroscopy to evaluate the structures of a joint. During both fluorography and "regular" X-ray studies, very tiny amounts of ionizing radiation rays penetrate your body. Some of the radiation energy is absorbed by your tissues. As the unabsorbed energy leaves your body, it’s “captured” by a special device that measures the energy waves. Those measurements are used to create the images of your joint. Denser structures like bones absorb more energy, which makes them appear whiter and brighter on the final images. Less dense areas appear darker. Traditional X-rays use film while digital X-rays use computer software to create the images. In addition to the “still” images created by regular X-rays, fluoroscopy lets your radiologist watch the joint as the contrast dye is injected or while the joint is in motion, which provides more detailed information that can be used to diagnose joint pain and injury.
We perform arthrography accompanied with MRI or CT in order to provide advanced musculoskeletal imaging. CT scanning also uses X-rays, but instead of creating a flat image of the joint, it takes multiple images that can be used to create a three-dimensional view of the joint as well. MRI doesn’t use X-rays. Instead, it uses very powerful magnets, radio waves and a computer. The magnets cause atoms inside your body to release energy that’s measured by the computer. Those measurements are used to create very detailed, three-dimensional images of your joint, allowing your doctor to view the joint from different angles.
What to expect during your arthrogram
During the exam, you’ll lie on a table. A local anesthetic will be injected first into the area around your joint. Once the area is numb, a longer needle will be gently inserted into the joint using ultrasound or fluoroscopy to guide it. A very small amount of air might also be injected to help expand the joint so the inside structures are easier to see. The radiologist also may move the joint during the exam to obtain additional images from different angles and to evaluate joint function. In MRIs and CT scans, the table glides on a special track, moving you through the imaging device. Most arthrograms take about a half hour to complete, but MRI studies can take longer.
After the exam, you’ll be able to go home. You may have some discomfort and minor swelling in the joint for a day or two. You can use ice and over-the-counter pain medicine to reduce discomfort, and you should avoid vigorous exercise for the first 24 hours to give the joint time to recover. The images from your exam will be reviewed by one of our board-certified radiologists and the final report will be sent to your doctor.