Joint design of trajectory and RF pulses for parallel excitation.
نویسندگان
چکیده
We propose an alternating optimization framework for the joint design of excitation k-space trajectory and RF pulses for small-tip-angle parallel excitation. Using Bloch simulations, we show that compared with conventional designs with predetermined trajectories, joint designs can often excite target patterns with improved accuracy and reduced total integrated pulse power, particularly at high reduction factors. These benefits come at a modest increase in computational time.
منابع مشابه
Magnetic Resonance in Medicine 58:598–604 (2007) Joint Design of Trajectory and RF Pulses for Parallel Excitation
We propose an alternating optimization framework for the joint design of excitation k-space trajectory and RF pulses for smalltip-angle parallel excitation. Using Bloch simulations, we show that compared with conventional designs with predetermined trajectories, joint designs can often excite target patterns with improved accuracy and reduced total integrated pulse power, particularly at high r...
متن کاملRF Pulse Design for Parallel Excitation
1. Introduction Parallel excitation has been introduced as a means of accelerating multi-dimensional, spatially-selective excitation using multiple transmit coils, each driven by a unique RF pulse (1,2). In a manner analogous to parallel imaging, parallel excitation allows the use of a reduced excitation k-space trajectory (7) to achieve a desired excitation pattern, by exploiting the blurring ...
متن کاملSparse parallel transmission on randomly perturbed spiral k-space trajectory.
Combination of parallel transmission and sparse pulse is able to shorten the excitation by using both the coil sensitivity and sparse k-space, showing improved fast excitation capability over the use of parallel transmission alone. However, to design an optimal k-space trajectory for sparse parallel transmission is a challenging task. In this work, a randomly perturbed sparse k-space trajectory...
متن کاملArray-compressed parallel transmit pulse design.
PURPOSE To design array-compressed parallel transmit radiofrequency (RF) pulses and compare them to pulses designed with existing transmit array compression strategies. THEORY AND METHODS Array-compressed parallel RF pulse design is proposed as the joint optimization of a matrix of complex-valued compression weights that relate a full-channel physical array to a reduced-channel virtual array,...
متن کاملSequential Optimal Spoke Selection for Spoke Trajectory Based RF Pulses Design in Parallel Excitation
INTRODUCTION: The spoke trajectory [1,2] is a preferred choice of k-space trajectory in designing 3D RF pulses for applications requiring thin slice selection and tailored in-plane excitation. It typically consists of several spokes of samples, each spoke extensively covering the kz (throughplane) axis at a distinct (kx,ky) (in-plane axes) location. Ideally, a large number of spokes should be u...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Magnetic resonance in medicine
دوره 58 3 شماره
صفحات -
تاریخ انتشار 2007