How is a quadrature coil signal readout achieved in MRI?

A quadrature coil is designed to capture both the real and imaginary components of the MRI signal simultaneously, which are essential for accurately reconstructing the image data. In the context of MRI, the signal obtained from the coils is represented as a complex number, where the real part corresponds to one phase of the magnetic resonance signal and the imaginary part corresponds to another phase.

By digitizing both the real and imaginary signals, the system can effectively utilize this complete dataset, allowing for more accurate image reconstruction. The combination of these components enables the MRI system to differentiate between the various signals, improving the overall quality and detail of the images produced.

This comprehensive approach to signal acquisition is crucial for maintaining good spatial resolution and contrast in MRI images, which relies on the accurate representation of the magnetic resonance data. Techniques that involve only isolating the real component, averaging signals from multiple coils, or applying a magnetic field gradient do not capture the full information needed for optimal image reconstruction.