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. Computed Tomography
• B. Magnetic Resonance Imaging
• C. Ultrasound
• D. Nuclear Medicine

Answer: (B)

MRI uses a strong magnetic field and radio waves to create images. A powerful magnet aligns the hydrogen protons in body water, and a radiofrequency pulse briefly tips this alignment. When the pulse stops, the protons realign and emit signals that are detected by coils. The signal characteristics depend on tissue properties, allowing the machine to distinguish different structures and produce detailed images. Because the method relies on magnetic fields and radio waves rather than ionizing radiation, it’s distinct from CT or nuclear medicine, which use X-rays or radioactive tracers. Ultrasound, on the other hand, images with high-frequency sound waves, not magnetic fields or radiofrequency energy.

MRI uses a strong magnetic field and radio waves to create images. A powerful magnet aligns the hydrogen protons in body water, and a radiofrequency pulse briefly tips this alignment. When the pulse stops, the protons realign and emit signals that are detected by coils. The signal characteristics depend on tissue properties, allowing the machine to distinguish different structures and produce detailed images. Because the method relies on magnetic fields and radio waves rather than ionizing radiation, it’s distinct from CT or nuclear medicine, which use X-rays or radioactive tracers. Ultrasound, on the other hand, images with high-frequency sound waves, not magnetic fields or radiofrequency energy.