Promotionsvortrag Physik: New Insights Into RF-Spoiling in FLASH MRI Using End-to-End Optimization

Ankündigung des Promotionsvortrags von: Herrn Simon Weinmüller

FLASH MRI is a fast imaging technique widely used in clinical practice. It enables rapid image acquisition using low flip-angle combined with RF and gradient spoiling. Under ideal spoiling con-ditions, transient signal evolution follows a Look-Locker decay, while steady-state signals are de-scribed by the Ernst equation.

In practice, however, higher echoes influence the signal. In the transient regime, they cause signal substructures known as Epstein artifacts. In the steady state, they introduce a dependence on RF-spoiling, challenging the assumption of ideal spoiling.

This work investigates transient and steady-state FLASH signal behavior using the differentiable simulation framework MR-zero and phase-distribution graph simulations. Transient signal sub-structures are reproduced, quantified, and suppressed through RF phase optimization.

It will be shown that diffusion plays a crucial role for the characteristic T1-weighted FLASH steady-state contrast and only certain phase difference increments fulfill the idea of RF-spoiling.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.