What is the role of the RF transmitter in the MRI process?

The RF transmitter plays a crucial role in the MRI process by exciting the hydrogen nuclei within the body's tissues. When a patient is placed in the strong magnetic field of the MRI scanner, the hydrogen nuclei, which are abundant in human tissue due to the high water content, align with that magnetic field. The RF transmitter emits radiofrequency pulses at specific frequencies that resonate with these hydrogen nuclei.

When the RF energy is applied, it causes the hydrogen nuclei to absorb energy and transition from a low-energy state to a higher-energy state. This state of excitation is temporary, and once the RF pulse is turned off, the nuclei will return to their original state. As they relax, they release energy in the form of signals that can be detected by the MRI scanner's receiver coils. These signals, or echoes, are then processed to create detailed images of the internal structures of the body.

This process of exciting the hydrogen nuclei is fundamental to magnetic resonance imaging, as it directly influences the quality and contrast of the resulting images. The functionality of the RF transmitter is essential in initiating the imaging sequence that enables the visualization of tissues, making it a key component of MRI technology.