If your doctor has ordered an arthrogram, there is an alternative for many patients--they can undergo what is called an 'indirect arthrogram'.
A conventional arthrogram involves a minor procedure where the skin over the joint is sterilized and draped. Then, local anesthetic is administered and a needle is placed into the joint. Next, the joint is distended with contrast and the patient then goes for an MRI (or sometimes, CT).
An indirect arthrogram is a much simpler procedure as the contrast is administered through an IV line instead. After a brief delay, the patient then undergoes the MRI without having a needle placed in the joint. For most clinical questions, the images from an indirect arthrogram are equivalent to those obtained after a conventional arthrogram.
This approach has a number of advantages, including decreased risk of infection and bleeding. Also, many patients are nervous for a procedure such as an arthrogram.
The conventional arthrogram is one of the many procedures that a musculoskeletal (MSK) radiologist specializes in. Since relatively few facilities have an MSK radiologist, the physican who performs the arthrograms often has limited experience. An indirect arthrogram may also be helpful in this case and make for a more pleasant experience for the patient.
Here is an article about the effectiveness of indirect arthrography in the shoulder that was published in Radiology.