MRI imaging uses radiofrequency pulses to excite hydrogen protons in the body's tissues within a strong magnetic field. The protons emit signals as they relax, which are detected and converted into detailed images. Unlike X-rays or gamma rays, MRI does not involve ionizing radiation, making it safer for soft tissue evaluation. This technique enables high-contrast imaging of muscles, brain, and other organs, crucial for accurate diagnosis. Understanding the role of radiofrequency pulses is essential for interpreting MRI results and optimizing imaging protocols.

Reference: Principles of Radiology, William R. Hendee, 5th Edition.