Projects

The Echo Modulation Curve (EMC) technique is a method for rapid and accurate mapping of the T2 relaxation time from multi spin-echo MRI acquisitions. EMC originated from prior work on model-based T2 estimation and replaces the analytical signal model with a dictionary of signal curves obtained through precise Bloch simulation of the acquisition sequence. Therefore, it accounts for effects such as stimulated echoes and achieves a much higher estimation accuracy than obtained with a simplified analytical model. Unlike the MR Fingerprinting (MRF) method, EMC does not rely on the use of specialized acquisition trajectories and can be combined with regular off-the-shelf multi spin-echo sequences.

Different variants of the EMC technique have been developed. In the basic variant, the EMC algorithm is added solely as post-processing step, working on exported DICOM images. This makes the approach very interesting for scenarios where sequence modifications are difficult to implement, e.g. due to regulatory constraints. In an advanced version, the EMC matching is integrated directly into an iterative reconstruction procedure. This makes the EMC method compatible with arbitrary k-space sampling trajectories, such as radial sampling, and enables incorporating a priori information into the reconstruction procedure, e.g. Compressed Sensing, which can be used to shorten the overall scan time.

Technical extensions are now mostly developed by the team of Noam Ben-Elizier at Tel Aviv University.

References

Ben-Eliezer N, Sodickson DK, Block KT. Rapid and accurate T2 mapping from multi-spin-echo data using Bloch-simulation-based reconstruction. Magn Reson Med. 2015; 73(2):809-817

Ben-Eliezer N, Sodickson DK, Shepherd T, Wiggins GC, Block KT. Accelerated and motion-robust in vivo T2 mapping from radially undersampled data using bloch-simulation-based iterative reconstruction. Magn Reson Med. 2016; 75(3):1346-1354

Ben-Eliezer N, Block KT. Method and Device for Accurate Quantification of T2 Relaxation Times Based on Fast Multi Spin-echo NMR Sequences. Patent US 10,281,544 B2

Block KT, Uecker M, Frahm J. Model-based iterative reconstruction for radial fast spin-echo MRI. IEEE Trans Med Imaging. 2009; 28(11):1759-1769