𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Design of a logarithmic k-space spiral trajectory

✍ Scribed by Harvey E. Cline; Xuli Zong; Neville Gai

Publisher
John Wiley and Sons
Year
2001
Tongue
English
Weight
247 KB
Volume
46
Category
Article
ISSN
0740-3194

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Spiral acquisitions are used in fast cardiac imaging because they traverse k‐space efficiently and minimize flow artifacts. A variable pitch logarithmic spiral trajectory is designed to critically sample the low‐frequency region in k‐space and gradually undersample the high‐frequency region. An approximate analytical expression for the trajectory provides a fast means to calculate the gradient waveforms and the sampled data points. A numerical method is introduced based on the trajectory curvature and the rate of change in the gradient magnitude with time for the composite Archimedean‐logarithmic trajectory. The pulse sequence is implemented and images are acquired on phantoms and human hearts. The images show improved image resolution and some improvement in image quality as a result of increased extent in k‐space and reduction in aliasing artifacts, respectively. Magn Reson Med 46:1130–1135, 2001. © 2001 Wiley‐Liss, Inc.

📜 SIMILAR VOLUMES

Optimal design of k-space trajectories u
Optimal design of k-space trajectories using a multi-objective genetic algorithm
✍ Brian M. Dale; Jonathan S. Lewin; Jeffrey L. Duerk 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 435 KB 👁 1 views

## Abstract Spiral, radial, and other nonrectilinear __k‐__space trajectories are an area of active research in MRI due largely to their typically rapid acquisition times and benign artifact patterns. Trajectory design has commonly proceeded from a description of a simple shape to an investigation

Fast three-dimensional k-space trajector
Fast three-dimensional k-space trajectory design using missile guidance ideas
✍ Roberto Mir; Andres Guesalaga; Juan Spiniak; Marcelo Guarini; Pablo Irarrazaval 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 266 KB

## Abstract Three‐dimensional (3D) __k__‐space trajectories are needed to acquire volumetric images in MRI. While scan time is determined by the trajectory efficiency, image quality and distortions depend on the shape of the trajectories. There are several 3D trajectory strategies for sampling the

Joint design of trajectory and RF pulses
Joint design of trajectory and RF pulses for parallel excitation
✍ Chun-Yu Yip; William A. Grissom; Jeffrey A. Fessler; Douglas C. Noll 📂 Article 📅 2007 🏛 John Wiley and Sons 🌐 English ⚖ 489 KB

## Abstract 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