Radiologic Technologist Practice Exam

Which imaging modality would primarily utilize magnetic fields and radio waves?

1. X-ray

2. Computed Tomography (CT)

3. Magnetic Resonance Imaging (MRI)

4. Ultrasound

The correct answer is: Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI) is the imaging modality that specifically utilizes magnetic fields and radio waves to generate detailed images of the organs and tissues within the body. MRI operates on the principles of nuclear magnetic resonance, where hydrogen atoms in the body are exposed to a strong magnetic field. This causes the protons in the hydrogen to align in a specific direction. When radiofrequency pulses are applied, these protons are temporarily knocked out of alignment. As they return to their original state, they emit signals that are detected by the MRI machine and converted into images. This technique is particularly advantageous for soft tissue imaging, making MRI invaluable in fields such as neurology, oncology, and musculoskeletal imaging. It provides high-resolution images without the use of ionizing radiation, which is a significant benefit compared to other modalities such as X-ray or CT imaging, both of which rely on similar principles but do not employ magnetic fields or radio waves. Ultrasound uses sound waves instead of magnetic fields, further differentiating it from MRI.