Pushing Transfer Insensitive Labeling Technique (TILT) from Pulsed Arterial Spin Labeling to Pulsed-Continuous Arterial Spin Labeling
نویسندگان
چکیده
imaging slab, Shadowed yellow: pTILT labeling slice, dashed yellow: TILT labeling slab, green: shimming volume. Fig.3: Simulated efficiencies as a function of velocity. T1 and T2 relaxations of blood are not considered in this simulation. Fig.4: top 2 rows: multislice perfusion maps by pTILT. Color map: CBF in mL/100mL/min. Last row: z-score activation map of the second row. Fig.1: MR pulse sequence of pTILT. Events in the dashed box form one labeling block. (+45, +45) is used for label session, (+45, -45) is used for control session. Tb: labeling block duration, Ts: total labeling duration, δ: postlabeling delay.
منابع مشابه
A theoretical and experimental comparison of continuous and pulsed arterial spin labeling techniques for quantitative perfusion imaging.
Under ideal conditions, continuous arterial spin labeling (ASL) techniques are higher in SNR than pulsed ASL techniques by a factor of e. Presented here is a direct theoretical and experimental comparison of continuous ASL and pulsed ASL, using versions of both that are amenable to multislice imaging and insensitive to variations in transit times (continuous ASL with a delay before imaging, and...
متن کاملContinuous flow-driven inversion for arterial spin labeling using pulsed radio frequency and gradient fields.
Continuous labeling by flow-driven adiabatic inversion is advantageous for arterial spin labeling (ASL) perfusion studies, but details of the implementation, including inefficiency, magnetization transfer, and limited support for continuous-mode operation on clinical scanners, have restricted the benefits of this approach. Here a new approach to continuous labeling that employs rapidly repeated...
متن کاملQuantifying CBF with pulsed ASL: technical and pulse sequence factors.
We summarize here current methods for the quantification of CBF using pulsed arterial spin labeling (ASL) methods. Several technical issues related to CBF quantitation are described briefly, including transit delay, signal from larger arteries, radio frequency (RF) slice profiles, magnetization transfer, tagging efficiency, and tagging geometry. Many pulsed tagging schemes have been devised, wh...
متن کاملOptimizing Perfusion Imaging of pTILT in the Presence of Magnetic Field Inhomogeneity
Introduction Pseudo-continuous transfer insensitive labeling technique (pTILT) is a novel pseudo-continuous arterial spin labeling method, which employs nonadiabatic saturation RF pulses for tagging [1]. However, magnetic field inhomogeneities, can compromise the labeling efficacy of pTILT, which induces loss in SNR and perfusion quantification errors. We propose a method to restore the signal ...
متن کاملPractical Investigation of pseudo-Continuous Arterial Spin Labeling (pCASL) feasibility at very high field (11.75T)
Introduction: A new strategy for continuous arterial spin labeling (CASL) using pulsed RF and gradient fields and referred as pseudo-continuous ASL (pCASL), has recently been developed and optimized for human studies at 3T. Promising results demonstrated that pCASL combines advantages of pulsed ASL (PASL) and CASL by providing good labeling efficiency, high Signal to Noise (SNR) and multi-slice...
متن کامل