Which imaging modality uses a strong magnetic field and radio waves to produce images?

Which imaging modality uses a strong magnetic field and radio waves to produce images?

• A. X-ray imaging
• B. Computed tomography
• C. Magnetic resonance imaging
• D. Ultrasound imaging

Answer: (C)

Magnetic resonance imaging uses a strong magnetic field and radio waves to produce images by detecting signals from hydrogen protons in the body. In the strong field, protons align with the magnet. A radiofrequency pulse disturbs this alignment, and as protons realign, they emit signals that are picked up by detectors. The way these signals return varies with tissue properties and relaxation times, creating highly detailed images, especially of soft tissues. This modality does not rely on ionizing radiation or sound waves. In contrast, X-ray and CT scanners use ionizing radiation to map density differences, while ultrasound uses high-frequency sound waves and echoes to form images.

Magnetic resonance imaging uses a strong magnetic field and radio waves to produce images by detecting signals from hydrogen protons in the body. In the strong field, protons align with the magnet. A radiofrequency pulse disturbs this alignment, and as protons realign, they emit signals that are picked up by detectors. The way these signals return varies with tissue properties and relaxation times, creating highly detailed images, especially of soft tissues. This modality does not rely on ionizing radiation or sound waves. In contrast, X-ray and CT scanners use ionizing radiation to map density differences, while ultrasound uses high-frequency sound waves and echoes to form images.