Tuned Exchange Imaging (TEXI) – A modified Filter-Exchange Imaging pulse sequence for applications with thin slices and restricted diffusion

Motivation: Thin slices in filter-exchange imaging lead to biased exchange rates, as thin slices require strong crushers. No current approach accounts for crushers in the presence of restricted diffusion. Goal(s): We set to address the bias in FEXI due to the influence of strong crushers and restricted diffusion. Approach: Tuned exchange imaging (TEXI) relies on gauging exchange and restriction weighting. We modify FEXI to ensure constant restriction weighting also with strong crushers. The accuracy of exchange mapping was evaluated using Monte Carlo simulations. Results: TEXI yields consistent exchange rates independent of slice thickness and restriction size even if strong crushers are used. Impact: TEXI could be useful to maximize exchange sensitivity and specificity with thin slices and in the presence of restricted diffusion.