Variable slew-rate spiral design: Theory and application to peakB1 amplitude reduction in 2D RF pulse design
نویسندگان
چکیده
منابع مشابه
Optimized amplitude modulated multiband RF pulse design
PURPOSE Multiband pulses are characterized by highly temporally modulated waveforms. Rapid phase or frequency modulation can be extremely demanding on the performance of radiofrequency (RF) pulse generation, which can lead to errors that can be avoided if pulses are restricted to amplitude modulation (AM) only. In this work, three existing multiband pulse design techniques are modified to produ...
متن کاملRF Pulse Toolkit: Application Specific Design
The most simple type of excitation pulse is known as a ‘hard’ pulse, and is illustrated in Fig. 1a. A hard pulse has constant magnitude and phase. Because MRI systems generate RF pulses using sample-and-hold DAC circuitry, all RF pulses can be accurately modeled as a series of short hard pulses of varying amplitude and phase. Figure 1b shows how magnetization rotates about a hard pulse, in a fr...
متن کاملSparsity-Enforced Joint Spiral Trajectory & RF Excitation Pulse Design
INTRODUCTION. Algorithms have recently been proposed that jointly optimize excitation k-space trajectories & RF excitation pulses [1-4]. Each relies on a small-tip-angle assumption and has been shown to produce higher-quality excitations or shorter excitation pulses than conventional 3D spoke-based [1,2], 2D echo-planar (EP) [3], and 2D spiral trajectories [4]. Here we propose a sparsity-enforc...
متن کاملPulse Design Methods for Reduction of Specific Absorption Rate in Parallel RF Excitation
A. C. Zelinski, K. Setsompop, V. Alagappan, B. A. Gagoski, L. M. Angelone, G. Bonmassar, U. Fontius, F. Schmitt, E. Adalsteinsson, and L. L. Wald Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, Siemens Medical Solutio...
متن کاملTo Design High CMRR, High Slew rate Instrumentation Amplifier using OTA and CDTA for Biomedical Application
In today’s world operational amplifier is used in lot of application. The techniques for achieving high slew rate and high CMRR is by cascading the transistors. This paper focus is on understanding of Operational Trans conductance Amplifier (OTA) and Current Differencing Trans conductance Amplifier (CDTA) with its application as Instrumentation Amplifier (IA) for Biomedical application. We have...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Magnetic Resonance in Medicine
سال: 2007
ISSN: 0740-3194,1522-2594
DOI: 10.1002/mrm.21375