What is the difference between a bone scan and a CT scan?
A bone scan and a CT scan are used to diagnose various bone conditions.
A bone scan and a computed tomography (CT) scan are both used to diagnose various bone conditions. The specific use of a bone scan is to diagnose active bone diseases, such as osteoporosis, Paget’s disease or the spread of cancer into the bone. A CT scan is a high-resolution X-ray that gives detailed information about organ anatomy.
Table. The difference between a bone scan and a CT scan
|Differences||Bone scan||CT scan|
|Description||A bone scan is a nuclear imaging test that aids in the diagnosis and tracking of several bone diseases.||A CT scan uses a combination of X-rays and a computer to create images of the bones.|
|Type||Nuclear imaging||Noninvasive diagnostic|
|Tools||Uses radioactive materials||Combination of X-ray and computer technology|
|Radiation exposure||There is minimal yet definite risk of radiation exposure||Higher risk of radiation exposure|
|Outcomes||It diagnoses active diseases of the bone.||Provides detailed information on bone tissue and bone structure. It also gives information about the injuries and diseases of the bone.|
|Safety||Generally, it is a safe procedure with occasional risks, including:
|Cost||Less expensive||More expensive|
|Duration||30 minutes to one hour||A few minutes to half an hour|
What to expect during a bone scan
You can expect the following procedure during a bone scan
- The procedure will be explained to you and your consent will be recorded.
- The physician will inject a radioactive substance into your vein.
- This substance collects in the bone over time.
- The radioactive substance then emits gamma rays that are picked up by a special camera.
- The signals are processed by a computer and turned into 2D (two-dimensional) or 3D (three-dimensional) pictures.
- A radiologist interprets the images and sends a report to your doctor.
What to expect during a CT scan
You can expect the following procedure during a CT scan
- You are secured to a scan table that slides into a large, round opening of the scanning machine. Pillows and straps may be used to prevent movement during the procedure.
- Once you are inside the machine, the scanner rotates around you. You will be exposed to X-rays for short intervals.
- The X-rays absorbed by body tissues are identified by the scanner and transmitted to the computer. The computer then converts the data into an image to be interpreted by a specialist.
- A CT scan may also be done after injecting a contrast dye to obtain better information.
Medically Reviewed on 1/21/2021
John Hopkins Medicine
American Cancer Society
Cancer Research UK