If net magnetization increases, what happens to imaging?

• A. More protons are manipulated for imaging
• B. Fewer protons are manipulated for imaging
• C. Imaging quality decreases
• D. Imaging is unaffected

Answer: (A)

A higher net magnetization means more protons are aligned with the main magnetic field, so more protons contribute to the MR signal. In MRI, the RF pulse converts this longitudinal magnetization into a transverse component that is detected as signal. With a larger initial magnetization, the resulting transverse magnetization is stronger, giving a higher signal-to-noise ratio and typically sharper, higher-quality images. Conversely, reducing net magnetization would weaken the signal and degrade image quality, while imaging would not remain unchanged. Thus, increasing net magnetization leads to more protons effectively used for imaging.