Reducing contamination while closing the gap: BASSI RF pulses in PASL.

Jan Warnking 1, * G Bruce Pike 1
Abstract : Bandwidth-modulated selective saturation and inversion (BASSI) pulses are a class of frequency- and gradient-modulated radiofrequency (RF) pulses, derived from the hyperbolic secant pulse by temporal variation of the bandwidth parameter. These pulses afford optimal amplitude modulation, achieving uniform and highly selective profiles at any effective flip angle. In this paper, BASSI pulses are parameterized to obtain low RF energy pulsed arterial spin labeling (PASL) label pulses with minimal contamination of static spins outside the label region and highly selective PICORE/QUIPSS II saturation pulses allowing for small label gaps. They are compared to frequency offset corrected inversion (FOCI) label pulses and sinc saturation pulses in simulations and a phantom experiment. Drawing on the outstanding selectivity of bandwidth-modulated saturation pulses, a new noninvasive method to measure in vivo the contamination effects due to direct and indirect saturation of static spins by the label pulse is presented. In an in vivo study on four subjects, contamination effects in a QUIPSS II PASL implementation based on BASSI pulses are compared to those present in a state-of-the-art Q2TIPS sequence employing a FOCI label pulse. Residual contamination in the QUIPSS II/BASSI sequence is shown to be reduced by a factor of 3, compared to the Q2TIPS/FOCI sequence. In vivo human perfusion images obtained with a label gap of only 2 mm are presented.
Type de document :
Article dans une revue
Magnetic Resonance in Medicine, Wiley, 2006, 55 (4), pp.865-73. 〈10.1002/mrm.20843〉
Liste complète des métadonnées

Littérature citée [29 références]  Voir  Masquer  Télécharger

http://www.hal.inserm.fr/inserm-00388986
Contributeur : Michel Dojat <>
Soumis le : lundi 17 août 2009 - 15:03:33
Dernière modification le : jeudi 11 janvier 2018 - 02:37:00
Document(s) archivé(s) le : samedi 26 novembre 2016 - 09:30:17

Fichier

 Accès restreint
Fichier visible le : jamais

Connectez-vous pour demander l'accès au fichier

Identifiants

Collections

Citation

Jan Warnking, G Bruce Pike. Reducing contamination while closing the gap: BASSI RF pulses in PASL.. Magnetic Resonance in Medicine, Wiley, 2006, 55 (4), pp.865-73. 〈10.1002/mrm.20843〉. 〈inserm-00388986〉

Partager

Métriques

Consultations de la notice

111