In which imaging method is ionizing radiation primarily used?

The use of ionizing radiation is a key characteristic of X-ray imaging. This method works by passing a controlled amount of radiation through the body to create images of bones and certain tissues. The X-ray radiation is absorbed at different rates by different tissues, which allows for the visualization of structures within the body.

Fluoroscopy also utilizes ionizing radiation, as it provides real-time imaging of a patient's internal structures, making it useful during certain procedures. However, X-ray is more commonly recognized specifically for its role in standard imaging practices.

In contrast, ultrasound and magnetic resonance imaging (MRI) do not use ionizing radiation. Ultrasound relies on sound waves to produce images, while MRI employs strong magnetic fields and radio waves to generate detailed images of organs and tissues. Therefore, in the context of imaging methods that primarily use ionizing radiation, X-ray stands out as the correct answer.