Method of producing an MRI image with gradient delay compensation

摘要

Gradient pulses are generated by current conducting gradient coils. High-frequency components cause the center of gravity of the current to be shifted by mutual influencing of the coil conductors. The shift depends on the electrical resistance of the conductor material, which in turn depends on the temperature of said conductor material, and on the frequency omega, such that the magnetic gradient field B decreases with increasing frequency. This phenomenon manifests itself as a delay tau of the gradient pulse with respect to the gradient demand D. During generation of a current gradient pulse in accordance with the gradient demand D, a quantity representing the conducting state of the conductors of the gradient system is determined and used to calculate the gradient delay tau to correct the gradient demand for the delay.