Technique uses magnetic fields and radio waves to produce images that distinguish soft tissues; see brain.

Technique uses magnetic fields and radio waves to produce images that distinguish soft tissues; see brain.

• A. Computed Tomography
• B. Ultrasonography
• C. Magnetic Resonance Imaging
• D. X-ray

Answer: (C)

The main concept is imaging that relies on magnetic fields and radio waves to differentiate soft tissues. In Magnetic Resonance Imaging, a strong static magnetic field aligns hydrogen nuclei in water and fat. A radiofrequency pulse perturbs them, and as they return to alignment they emit signals that vary with tissue properties such as proton density and T1/T2 relaxation times. The scanner uses gradient fields to localize these signals, producing detailed cross-sectional images with excellent soft-tissue contrast. This makes it particularly effective for brain imaging, where distinguishing gray matter, white matter, CSF, edema, and lesions is crucial. Unlike CT or X-ray, MRI does not involve ionizing radiation. Ultrasonography relies on sound waves and has limited ability to image the brain through the skull, which is why it isn’t used for this purpose.

The main concept is imaging that relies on magnetic fields and radio waves to differentiate soft tissues. In Magnetic Resonance Imaging, a strong static magnetic field aligns hydrogen nuclei in water and fat. A radiofrequency pulse perturbs them, and as they return to alignment they emit signals that vary with tissue properties such as proton density and T1/T2 relaxation times. The scanner uses gradient fields to localize these signals, producing detailed cross-sectional images with excellent soft-tissue contrast. This makes it particularly effective for brain imaging, where distinguishing gray matter, white matter, CSF, edema, and lesions is crucial. Unlike CT or X-ray, MRI does not involve ionizing radiation. Ultrasonography relies on sound waves and has limited ability to image the brain through the skull, which is why it isn’t used for this purpose.