### 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 language | English (US) |
---|---|

Pages (from-to) | 285-293 |

Number of pages | 9 |

Journal | Journal of magnetic resonance imaging : JMRI |

Volume | 2 |

Issue number | 3 |

State | Published - May 1992 |

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### ASJC Scopus subject areas

- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology

### Cite this

*Journal of magnetic resonance imaging : JMRI*,

*2*(3), 285-293.

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

Research output: Contribution to journal › Article

*Journal of magnetic resonance imaging : JMRI*, vol. 2, no. 3, pp. 285-293.

}

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.

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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 -