Side Effects of CT Scans

A computed tomography (CT) scan, also known as a CAT scan, is an advanced technique in medical imaging that uses X-rays and specialized computer software to create highly detailed cross-sectional images of the body. These images assist patient care teams in making critical decisions regarding diagnosis and treatment planning. 

In neurology and neurosurgery, “brain CT” or “head CT” scans are used to examine the brain and its associated structures. 

When you undergo a CT scan, you'll lie on a table that slides into a large, ring-shaped machine. The scanner rotates around you, taking multiple X-ray images from different angles. 

The entire procedure takes approximately 10 to 20 minutes, depending on the parts of the body being evaluated. For some CT scans, you may need to receive a contrast material by mouth, or via an intravenous injection to help certain tissues show up more clearly in the images.

CT scans are particularly useful for examining the brain and spine, and can help diagnose various conditions, including:

• Brain tumors
• Skull fractures
• Bleeding in the brain
• Stroke
• Hydrocephalus (fluid buildup in the brain)
• Spinal alignment conditions
• Fractures of the spine
• Herniated (slipped) discs in the spinal column

A CT scan of the brain and/or spine can provide crucial information about the size, location, and nature of abnormalities, helping guide treatment decisions.

While CT scans are generally safe and without significant discomfort, there are some potential side effects and risks to be aware of:

CT scans use ionizing radiation, which in high doses can potentially increase the risk of cancer. However, the radiation dose from a single CT scan is relatively low. The risk is thought to be very small, with the chances of developing a fatal cancer due to a CT scan estimated at about 1 in 2,000.

It’s important to note that the benefits of a medically necessary CT scan typically outweigh the small potential risk from radiation exposure. Modern CT scanners are designed to use the lowest radiation dose possible while still producing high-quality images.

If your CT scan requires contrast material, there's a small risk of an allergic reaction. Most reactions are mild, causing symptoms like itchiness or a rash. Some people may experience side effects from the contrast material, including:

• Nausea and vomiting
• Headaches
• Dizziness
• A warm, flushed sensation
• A metallic taste in the mouth

These effects are usually temporary and resolve on their own. In rare cases, more severe allergic reactions can occur.

In rare cases, the contrast material used in CT scans can affect kidney function, particularly in people with pre-existing kidney problems or diabetes. Your doctor will assess your kidney function before administering contrast material if there's any concern.

It is not uncommon for CT scans to reveal abnormalities unrelated to the original reason for the scan. While these "incidental findings" can sometimes lead to early detection of serious conditions, they may also lead to significant further clinical investigation that may require long-term follow-up. 

Be sure to discuss the vital necessity of a CT scan with your healthcare provider, and understand the implications of incidentally discovered findings. 

Certain vulnerable populations require particular attention and care when it comes to CT scan risks and side effects. 

If you're pregnant or think you might be, it's crucial to inform your healthcare provider before having a CT scan. While the radiation from a CT scan of the head is unlikely to harm an unborn baby, your doctor may recommend alternative imaging methods like ultrasound or MRI.

Children are more sensitive to radiation than adults, so special care should be taken when performing CT scans on pediatric patients. The CT machine's settings are adjusted to use the lowest possible radiation dose while still obtaining the necessary images.

To minimize the potential side effects associated with CT scans:

• Only undergo CT scans when medically necessary.
• Inform your healthcare provider about any allergies or previous reactions to contrast materials.
• Tell your doctor if you have kidney problems or diabetes.
• If you're pregnant or think you might be, inform your healthcare provider.
• For children, ask if the CT settings have been adjusted for pediatric use.

• CT scans are valuable diagnostic tools in neurology and neurosurgery, providing detailed images of the brain and spine, aiding in the diagnosis of various conditions.
• While generally safe, CT scans do involve exposure to ionizing radiation, which carries a very small potential risk of radiation-related illnesses, such as cancer.
• Some people may experience mild side effects from contrast materials used in CT scans.
• Pregnant women and children require special considerations when undergoing CT scans.
• The benefits of a medically necessary CT scan typically outweigh the potential risks.
• Always inform your healthcare provider about any concerns or medical conditions you may have before undergoing a CT scan.

• United States Food & Drug Administration (FDA): CT Scan Risks
• National Institute of Biomedical Imaging and Bioengineering (NIBIB): CT Scan
• American Association of Neurological Surgeons (AANS): Cerebrovascular Imaging
• National Health Service (NHS) [UK]: CT Scan