Analysis of flow effects in echo-planar imaging.

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

The effects on the phase of spins moving during echo-planar imaging (EPI) acquisition were studied. Standard single-shot and interleaved multishot blipped EPI acquisitions were considered, assuming either high gradient strength and slew rates or standard gradient strength and slew rates. A spiral k-space trajectory was also considered. Flow components in the section-select and phase- and frequency-encoding directions were analyzed separately. While the effect of flow in the section-select direction is identical to that in a standard two-dimensional Fourier transform (2DFT) acquisition, flow in the phase- or frequency-encoding directions can have substantial effects on the image, different from that in 2DFT imaging. The magnitude of these effects, which include displacement, distortion, and/or ghosting of vascular structures, is analyzed and predicted for a given velocity and direction of flow, the specific acquisition sequence, and the strength and slew rate of the gradients. For example, 50-cm/sec flow along the phase-encoding direction can cause a blurring of 1.25 cm full width at half maximum for blipped EPI with high-strength gradients, assuming a 40-cm field of view and 64 x 64 matrix.

Original languageEnglish (US)
Pages (from-to)285-293
Number of pages9
JournalJournal of magnetic resonance imaging : JMRI
Volume2
Issue number3
StatePublished - May 1992

Fingerprint

Echo-Planar Imaging
Fourier Analysis
Blood Vessels
Direction compound

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Analysis of flow effects in echo-planar imaging. / Butts, K.; Riederer, Stephen J.

In: Journal of magnetic resonance imaging : JMRI, Vol. 2, No. 3, 05.1992, p. 285-293.

Research output: Contribution to journalArticle

@article{1d25df6759ba44d4bb5a022e05b6175a,
title = "Analysis of flow effects in echo-planar imaging.",
abstract = "The effects on the phase of spins moving during echo-planar imaging (EPI) acquisition were studied. Standard single-shot and interleaved multishot blipped EPI acquisitions were considered, assuming either high gradient strength and slew rates or standard gradient strength and slew rates. A spiral k-space trajectory was also considered. Flow components in the section-select and phase- and frequency-encoding directions were analyzed separately. While the effect of flow in the section-select direction is identical to that in a standard two-dimensional Fourier transform (2DFT) acquisition, flow in the phase- or frequency-encoding directions can have substantial effects on the image, different from that in 2DFT imaging. The magnitude of these effects, which include displacement, distortion, and/or ghosting of vascular structures, is analyzed and predicted for a given velocity and direction of flow, the specific acquisition sequence, and the strength and slew rate of the gradients. For example, 50-cm/sec flow along the phase-encoding direction can cause a blurring of 1.25 cm full width at half maximum for blipped EPI with high-strength gradients, assuming a 40-cm field of view and 64 x 64 matrix.",
author = "K. Butts and Riederer, {Stephen J}",
year = "1992",
month = "5",
language = "English (US)",
volume = "2",
pages = "285--293",
journal = "Journal of Magnetic Resonance Imaging",
issn = "1053-1807",
publisher = "John Wiley and Sons Inc.",
number = "3",

}

TY - JOUR

T1 - Analysis of flow effects in echo-planar imaging.

AU - Butts, K.

AU - Riederer, Stephen J

PY - 1992/5

Y1 - 1992/5

N2 - The effects on the phase of spins moving during echo-planar imaging (EPI) acquisition were studied. Standard single-shot and interleaved multishot blipped EPI acquisitions were considered, assuming either high gradient strength and slew rates or standard gradient strength and slew rates. A spiral k-space trajectory was also considered. Flow components in the section-select and phase- and frequency-encoding directions were analyzed separately. While the effect of flow in the section-select direction is identical to that in a standard two-dimensional Fourier transform (2DFT) acquisition, flow in the phase- or frequency-encoding directions can have substantial effects on the image, different from that in 2DFT imaging. The magnitude of these effects, which include displacement, distortion, and/or ghosting of vascular structures, is analyzed and predicted for a given velocity and direction of flow, the specific acquisition sequence, and the strength and slew rate of the gradients. For example, 50-cm/sec flow along the phase-encoding direction can cause a blurring of 1.25 cm full width at half maximum for blipped EPI with high-strength gradients, assuming a 40-cm field of view and 64 x 64 matrix.

AB - The effects on the phase of spins moving during echo-planar imaging (EPI) acquisition were studied. Standard single-shot and interleaved multishot blipped EPI acquisitions were considered, assuming either high gradient strength and slew rates or standard gradient strength and slew rates. A spiral k-space trajectory was also considered. Flow components in the section-select and phase- and frequency-encoding directions were analyzed separately. While the effect of flow in the section-select direction is identical to that in a standard two-dimensional Fourier transform (2DFT) acquisition, flow in the phase- or frequency-encoding directions can have substantial effects on the image, different from that in 2DFT imaging. The magnitude of these effects, which include displacement, distortion, and/or ghosting of vascular structures, is analyzed and predicted for a given velocity and direction of flow, the specific acquisition sequence, and the strength and slew rate of the gradients. For example, 50-cm/sec flow along the phase-encoding direction can cause a blurring of 1.25 cm full width at half maximum for blipped EPI with high-strength gradients, assuming a 40-cm field of view and 64 x 64 matrix.

UR - http://www.scopus.com/inward/record.url?scp=0026856564&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026856564&partnerID=8YFLogxK

M3 - Article

C2 - 1627863

AN - SCOPUS:0026856564

VL - 2

SP - 285

EP - 293

JO - Journal of Magnetic Resonance Imaging

JF - Journal of Magnetic Resonance Imaging

SN - 1053-1807

IS - 3

ER -