Z-segmentation of a transmit array head coil improves RF ramp pulse design at 7T

Gaël Saïb (1, 2) , Raphael Tomi-Tricot (1) , Vincent Gras (1) , Franck Mauconduit (3) , Nicolas Boulant (1) , Alexandre Vignaud (1) , Michel Luong (4) , Eric Giacomini (1) , Edouard Chazel (1) , Denis Le Bihan (1) , Laurent Le Brusquet (2) , Alexis Amadon (1)

1 UNIRS - Unité d'imagerie par résonance magnétique à très haut champ et de spectroscopie
2 L2S - Laboratoire des signaux et systèmes
3 Siemens Healthineers
4 DACM - Département des Accélérateurs, de Cryogénie et de Magnétisme (ex SACM)

In Time-Of-Flight sequences, ramp pulses such as TONE's are frequently used to compensate for thru-slab blood flow saturation in cerebral MRA. At Ultra High Field, fast-kz spokes in parallel transmission allow to mitigate B1 + heterogeneities in the slab selection process. Here we extend their use for TONE pulses and show improvement of the flip angle ramp fidelity with a homemade z-segmented head array in comparison to a purely azimuthally-distributed commercial coil.

Mots clés: Parallel transmission; MRI Imaging

Domaines: Santé publique et épidémiologie; Modélisation et simulation; Traitement du signal et de l'image [eess.SP]

Gaël Saïb, Raphael Tomi-Tricot, Vincent Gras, Franck Mauconduit, Nicolas Boulant, et al.. Z-segmentation of a transmit array head coil improves RF ramp pulse design at 7T. Joint Annual Meeting ISMRM-ESMRMB 2018, Jun 2018, Paris, France. ⟨hal-01633707⟩