Inductive measurement and encoding of k -space trajectories in MR raw data

The objective of this study was to concurrently acquire an inductivek-space trajectory measure and corresponding imaging data by an MR scanner.Materials and methods 1D gradient measures were obtained by digital integration, regularized using measured gradient coil currents and recorded individually by the scanner concurrently with raw MR data. Gradient measures were frequency modulated into an RF signal receivable by the scanner, yielding ak-space trajectory measure from the cumulative phase of the acquired data. Generation of the gradient measure and frequency modulation was performed by previously developed custom, versatile circuitry.Results For a normal echo planar imaging (EPI) sequence, the acquiredk-space trajectory measure yielded slightly improved image quality compared to that obtained from using the scanner ’s estimated eddy current-compensatedk-space trajectory. For a spiral trajectory, the regularized inductivek-space trajectory measure lead to a 76% decrease in the root-mean-square error of the reconstructed image.Discussion While the proof-of-concept experiments show potential for further improvement, the feasibility of inductively measuringk-space trajectories and increasing the precision through regularization was demonstrated. The approach may offer an inexpensive method to acquirek-space trajectories concurrently with scanning.
Source: Magnetic Resonance Materials in Physics, Biology and Medicine - Category: Materials Science Source Type: research