Arm CT scan
Definition
A computed tomography (CT) scan of the arm is an imaging method that uses x-rays to make cross-sectional pictures of the arm.
How the Test is Performed
You will be asked to lie on a narrow table that slides into the center of the CT scanner.
Once you are inside the scanner, the machine's x-ray beam rotates around you. Modern "spiral" scanners can perform the exam without stopping.
A computer creates separate images of the arm area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the arm can be created by adding the slices together.
You must be still during the exam. Movement can cause blurred images. You may be told to hold your breath for short periods of time.
The scan should take only 10 to 15 minutes.
How to Prepare for the Test
For some tests, you will need to have a special dye, called contrast, to be delivered into the body before the test starts. Contrast helps certain areas show up better on the x-rays.
If you weigh more than 300 pounds (135 kilograms), find out if the CT machine has a weight limit. Too much weight can cause damage to the scanner's working parts.
You will be asked to remove jewelry and wear a hospital gown during the study as metal can affect the CT images.
How the Test will Feel
Some people may have discomfort from lying on the hard table.
Contrast given through an IV may cause a slight burning sensation, a metallic taste in the mouth, and a warm flushing of the body. These feelings are normal. They will go away within a few seconds.
Why the Test is Performed
CT rapidly creates detailed pictures of the body, including the arms. The test may help detect or diagnose:
A CT scan may also be used to guide a surgeon to the right area during a .
Normal Results
Results are considered normal if no problems are seen in the images.
What Abnormal Results Mean
Abnormal results may be due to:
Risks
Risks of CT scans include:
CT scans expose you to more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a medical problem.
Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.
Rarely, the dye may cause a life-threatening allergic response called anaphylaxis. If you have any trouble breathing during the test, let the scanner operator know right away. Scanners have intercom and speakers so the operator can hear you at all times.
References
Kapoor G, Toms AP. Current status of imaging of the musculoskeletal system. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 38.
Perez EA. Fractures of the shoulder, arm, and forearm. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 57.
Review Date: 4/24/2023
Reviewed By: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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