A spine CT scan for back pain involves exposure to ionizing radiation, but the amount of radiation is generally moderate and carefully controlled to balance diagnostic benefit with safety. Typically, a CT scan of the spine delivers a radiation dose ranging roughly from about 3 to 10 millisieverts (mSv), depending on the specific protocol, the part of the spine scanned (cervical, thoracic, or lumbar), and the machine settings. This dose is higher than that of a standard X-ray but lower than many other medical CT scans.
To put this into perspective, the average person is naturally exposed to about 3 mSv of background radiation annually from the environment. So, a spine CT scan might expose you to roughly the equivalent of one to three years of natural background radiation. This level of exposure is considered acceptable in medical imaging because the detailed images provided by CT scans are crucial for diagnosing causes of back pain such as herniated discs, spinal stenosis, fractures, or tumors.
CT scans use X-rays to create cross-sectional images of the spine, which provide much more detailed information than plain X-rays. However, because CT involves ionizing radiation, it carries a small risk of radiation-induced effects, which is why doctors weigh the benefits against the risks before recommending the scan. Modern CT scanners use advanced technology to minimize radiation dose while maintaining image quality, such as dose modulation and faster scanning times.
For patients with back pain, a CT scan is often reserved for cases where MRI is contraindicated (for example, if the patient has certain metal implants or pacemakers) or when bone detail is especially important. MRI is preferred when possible because it does not use ionizing radiation and provides excellent images of soft tissues like discs and nerves.
In summary, a spine CT scan exposes you to a moderate amount of radiation—more than a standard X-ray but within safe limits for medical imaging. The exact dose depends on the scan type and equipment, but it is carefully managed to ensure patient safety while providing critical diagnostic information for back pain evaluation.