Improved spectroscopic imaging using echo-planar scans and sparse reconstruction
Haldar J, Liang Z, Jacob M, Sutton B
We find that the model based spectroscopic imaging framework, originally derived for reduced encoding, is more appropriate for fast-scan techniques; these schemes can provide larger k-space coverage in the same scan time as the reduced phase encoding case. This enables us to redesign the model-based framework to these schemes, thus simultaneously achieving high spatial resolution, signal to noise ratio, and low artifacts. We then present a data-adaptive basis selection procedure to rectify some of the problems associated with the current model based techniques. To achieve this goal, we propose to specify the basis functions using linear constraints. We start with a rigid image model, formulated in this framework. We then relax some of its constraints based on the MRSI data. This enables us to make the model flexible, without losing its robustness.