title: FAST sequences optimization for contrast media pharmacokinetic quantification in tissue.
abstract: The purpose of this study was to investigate the influence of the fast gradient-recalled echo (GRE) sequence parameters on the contrast dynamic range and signal sensitivity, to optimize the magnetic resonance (MR) sequence for contrast media pharmacokinetic assessment. Effects of the fast low-angle shot (FLASH), Fast acquisition at steady rate (FAST), and radiofrequency-spoiled (RF)-FAST sequence parameters were studied in vitro. The FAST sequence had the highest sensitivity in low gadolinium (Gd) concentration. The FLASH and RF-FAST sequences had a larger contrast dynamic range, but the FLASH images contained side band artifacts. Increasing the flip angle to 90 degrees raised the sensitivity of the FAST sequence and the contrast dynamic range of the RF-FAST sequence. The shortest possible TE was optimal for both contrast dynamics and imaging time. TI had an influence on the sensitivity of the FAST sequence only for small acquisition matrices. This study indicates the optimal parameters for contrast dynamics (RF-FAST, 90 degrees flip angle, shortest possible TE) and sensitivity (FAST, 90 degrees flip angle, long TI(eff)).
authors.affiliation: Department of Radiology, Geneva University Hospital, Geneva, Switzerland. marko.ivancevic@physics.unige.ch
authors.forename: M K
authors.initials: MK
authors.lastname: Ivancevic
authors.forename: I
authors.initials: I
authors.lastname: Zimine
authors.forename: F
authors.initials: F
authors.lastname: Lazeyras
authors.forename: D
authors.initials: D
authors.lastname: Foxall
authors.forename: J P
authors.initials: JP
authors.lastname: Vallée
mesh_terms: D003287:Contrast Media / Q000493:pharmacokinetics*; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA