Magnetic Resonance Imaging (MRI) Practice Test

What process digitizes the MR signals in MRI?

1. Signal conversion

2. Fourier transform

3. Phase encoding

4. Quantum detection

The correct answer is: Fourier transform

The process that digitizes the MR signals in MRI is the Fourier transform. This mathematical technique is crucial for converting the raw data collected during an MRI scan, which is typically in the form of time-domain signals, into a format that can be interpreted visually—namely, the frequency-domain representation. In MRI, after receiving signals from the scanned area of the body, a complex set of electromagnetic signals are generated. However, these signals alone do not provide usable images. The Fourier transform takes these time-varying signals and decomposes them into their constituent frequencies, allowing for reconstruction of the spatial information within tissues. This transformation provides a detailed image by representing how different tissues respond to the magnetic field and radio waves. By utilizing the Fourier transform, MRI systems can effectively interpret the signals and create the high-resolution images that are essential for diagnostic purposes. Thus, understanding the role of the Fourier transform is fundamental to grasping how MR signals are processed into meaningful images.