Joint CT scans take multiple X-rays from various horizontal and vertical angles. These images are processed by a computer and combined into cross-sectional 3-D representations, which are examined by our radiologists. Typically, a joint CT scan focuses on the shoulder, elbow, wrist, hip, knee, or ankle.
Joint CT vs. Joint X-ray
While conventional X-ray imaging may capture bone structure, it does not display soft tissue with enough clarity. Joints are complicated structures comprised of soft tissue and bones that support body movement. Therefore, a more advanced form of imaging is required. CT scanning is the preferred imaging method for joints, as it clearly captures highly detailed images of the bone structure.
Reasons for a Joint CT Scan
Your doctor or surgeon may order a joint CT scan to help them plan for a procedure or therapy. The images can also be used to evaluate how your body is responding to therapy. Your doctor may also order a joint CT to:
- Look for fractures that are difficult to detect with ordinary X-rays
- Assess fracture healing
- Assess degenerative changes and check for loose bodies inside joints
- Check for abnormal tumors, growths, or lumps
Lower Joints vs. Upper Joints
There are two main groups of joints, upper and lower, classified by their location in the body.
Lower joints include:
Upper joints include:
During a joint CT, your body position and orientation will depend on whether you are having an upper or lower joint scanned.
Typically, if you are having an upper joint scanned, you will lie flat on your stomach, with the arm extended above your head. You will be moved into the scanner arm-first, only as far as needed to image the desired location.
The main exception to this orientation is when you are having your shoulder scanned. You will lie on your back, with your arms by your side, and you will be moved into the scanner head-first until your shoulder is in position for imaging.
If you are having a lower joint scanned, you will lie on your back and be moved into the scanner feet-first.
A joint CT scan lasts approximately 30 minutes.
Being prepared for your CT scan helps us take the best possible images for diagnosis. Please visit our exam prep page for more instructions specific to joint CT preparation.