Certified Healthcare Constructor (CHC) Practice Exam

Does an MRI machine use radiation to produce its images?

1. Yes, it uses ionizing radiation

2. No, it uses magnetic and radio frequencies

3. Yes, it uses sound waves

4. No, it operates on electrical impulses

The correct answer is: No, it uses magnetic and radio frequencies

MRI machines do not use ionizing radiation to create images. Instead, they utilize a combination of powerful magnetic fields and radiofrequency waves. When a patient is placed inside the MRI scanner, the magnetic field aligns the hydrogen atoms in the body, primarily found in water and fat. The radiofrequency pulses then disturb this alignment, and when the atoms return to their original position, they emit signals that are detected by the MRI machine. These signals are then processed to create detailed images of the internal structures of the body. This method is safe and does not expose patients to radiation, making it a preferred imaging technique for many diagnostic purposes, especially in sensitive populations such as pregnant women or those requiring frequent imaging. Other imaging modalities, like X-rays or CT scans, use ionizing radiation, but that is not the case for MRI. Thus, the understanding of how MRI works is crucial for recognizing its advantages and applications in healthcare.