X-Rays & Cat Scans

To diagnose a broken ankle, an x-ray may be required.

When someone suffers an internal injury, physicians may perform a medical imaging test to determine a diagnosis and treatment plan. X-rays and CT (sometimes pronounced as "cat") scans are two of these tests.

X-Rays

An X-ray is created by electromagnetic radiation forming an image on film. Bones absorb the most radiation, causing them to appear white on the film. Fat and soft tissue absorb some radiation, appearing gray, and air absorbs the least amount, so those areas appear black.

CT Scans

Computed tomography scans, or CT scans, also use electromagnetic radiation to create images but require specialized equipment to form a cross-sectional image of a patient's body. Contrast dye is needed to create these images, which are obtained when the patient lies on a table that passes through an x-ray machine.

Radiation Exposure

X-rays create minimal radiation exposure. With CT scans, depending on the lifetime number of exams performed and radiation dose, patients may develop other health problems such as cancer. In February 2010, the FDA announced an initiative to reduce unnecessary radiation exposure from imaging tests such as CT scans.

References

• Medline Plus: X-Rays
• Medline Plus: CT Scans
• NPR: Radiation From CT Scans May Raise Cancer Risk
• U.S. Food and Drug Administration: FDA Unveils Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging