Prior-information-driven multiple contrast projection of T 2 weighted magnetic resonance images

Abstract

Despite the tremendous improvements in MR imaging, the optimization of fast imaging techniques for display of T2 contrast has not yet been accomplished. Existing methods that make use of prior-information (feature-recognizing MRI, constrained reconstruction techniques, dynamic imaging etc) are sub-optimal. In this paper, we present a fast, robust method to enhance the T2 related contrast in an MRI image acquired at, but not restricted to, just-enough-to-highlight-T2 repetition time so as to produce a computed mosaic of the same image at different repetition (TR) and echo (TE) times. This leads to substantial reduction in scan time and simultaneous provision of multiple snapshots of the same image at different TR and TE time settings. The enhanced mapping is performed using a feature-guided, non-linear equalization technique based on prior knowledge. The proposed methodology could be synergistically cascaded with other fast imaging techniques to further improve the acquisition rate. The clinical applications of the proposed contrast enhancement technique include: a pre-scan application in which projected images assist in prescribing a subsequent image acquisition; a real-time application in which images are acquired quickly with a short TR from which projected images at long TR are produced in near real-time; and post processing applications where enhanced images are produce to assist in diagnosis.