𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Design of symmetric-sweep spectral-spatial RF pulses for spectral editing

✍ Scribed by Charles H. Cunningham; Daniel B. Vigneron; Albert P. Chen; Duan Xu; Ralph E. Hurd; Napapon Sailasuta; John M. Pauly

Publisher
John Wiley and Sons
Year
2004
Tongue
English
Weight
421 KB
Volume
52
Category
Article
ISSN
0740-3194

No coin nor oath required. For personal study only.

✦ Synopsis

Spectral-spatial RF (SSRF) pulses allow simultaneous selection in both frequency and spatial domains. These pulses are particularly important for clinical and research MR spectroscopy (MRS) applications for suppression of large water and lipid resonances. Also, the high bandwidth of the subpulses (5-10 kHz) greatly reduces the spatial-shift errors associated with different chemical shifts. However, the use of high-bandwidth subpulses along with enough spectral bandwidth to measure a typical range of metabolite frequencies (e.g., 300 Hz at 3 T) can require RF amplitudes beyond the limits of the RF amplifier of a typical scanner. In this article, a new method is described for designing nonlinear-phase 180 degrees SSRF pulses that can be used for spectral editing. The novel feature of the pulses is that the spectral profile develops as a symmetric sweep, from the outside edges of the spectral window towards the middle, so that coupled components are tipped simultaneously and over a short interval. Pulses were designed for lactate editing at 1.5 T and 3 T. The spectral and spatial spin-echo profiles of the new pulses were measured experimentally. Spectra acquired in phantom experiments showed a well-resolved, edited lactate doublet, with 91% to 93% editing efficiency.

📜 SIMILAR VOLUMES

Dualband spectral-spatial RF pulses for
Dualband spectral-spatial RF pulses for prostate MR spectroscopic imaging
✍ Amir A. Schricker; John M. Pauly; John Kurhanewicz; Mark G. Swanson; Daniel B. V 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 324 KB

## Abstract Although MR spectroscopic imaging (MRSI) of the prostate has demonstrated clinical utility for the staging and monitoring of cancer extent, current acquisition methods are often inadequate in several aspects. Conventional 180° pulses can suffer from chemical shift misregistration, and h

Simple analytical dual-band spectral-spa
Simple analytical dual-band spectral-spatial RF pulses for B1+ and susceptibility artifact reduction in gradient echo MRI
✍ Cungeng Yang; Weiran Deng; V. Andrew Stenger 📂 Article 📅 2010 🏛 John Wiley and Sons 🌐 English ⚖ 404 KB

## Abstract Susceptibility artifacts and transmission radio frequency (RF) field (__B__~1~+) inhomogeneity are major limitations in high‐field gradient echo MRI. Previously proposed numerical 2D spectral‐spatial RF pulses have been shown to be promising for reducing the through‐plane signal loss su

Spectral-spatial pulse design for throug
Spectral-spatial pulse design for through-plane phase precompensatory slice selection in T-weighted functional MRI
✍ Chun-Yu Yip; Daehyun Yoon; Valur Olafsson; Sangwoo Lee; William A. Grissom; Jeff 📂 Article 📅 2009 🏛 John Wiley and Sons 🌐 English ⚖ 497 KB

## Abstract __T__‐weighted functional MR images suffer from signal loss artifacts caused by the magnetic susceptibility differences between air cavities and brain tissues. We propose a novel spectral‐spatial pulse design that is slice‐selective and capable of mitigating the signal loss. The two‐dim

Dixon techniques in spiral trajectories
Dixon techniques in spiral trajectories with off-resonance correction: A new approach for fat signal suppression without spatial-spectral RF pulses
✍ Hisamoto Moriguchi; Jonathan S. Lewin; Jeffrey L. Duerk 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 317 KB

## Abstract Spiral imaging has recently gained acceptance in MR applications requiring rapid data acquisition. One of the main disadvantages of spiral imaging, however, is blurring artifacts that result from off‐resonance effects. Spatial‐spectral (SPSP) pulses are commonly used to suppress those s

Self-refocused spatial-spectral pulse fo
Self-refocused spatial-spectral pulse for positive contrast imaging of cells labeled with SPIO nanoparticles
✍ Priti Balchandani; Mayumi Yamada; John Pauly; Phillip Yang; Daniel Spielman 📂 Article 📅 2009 🏛 John Wiley and Sons 🌐 English ⚖ 311 KB

## Abstract MRI has been used extensively to noninvasively track the location of cells labeled with superparamagnetic iron‐oxide nanoparticles (SPIOs) in vivo. Typically, SPIOs are employed as a negative contrast agent which makes it difficult to differentiate labeled cells from extraneous sources