### Abstract

In order to set up magnetic resonance imaging (MRI) procedures of arbitrary voxel dimensions, slice orientation, and sequence timing in a reasonable time, some form of automatic gradient pulse calibration is required. One such method, involving simulation of gradient waveforms, is presented. Waveforms are modeled based on measurements of the step response. The model used divides each transition into three time regions: a 'start' region in the first 0.3 ms, a 'slew' region, and a 'tail' region representing decay of the eddy current compensation error. In the 'slew' region, the time derivative of the gradient, G'(t), is expressed as a function of G(t). The first two regions are nonlinear with respect to demand. The mean error in the simulated gradient is generally less than 0.04 mT m^{-1} in spin echo sequences. Image signal/noise ratios resulting from sequences calibrated using the model are within 5% of those of empirically calibrated sequences.

Original language | English (US) |
---|---|

Pages (from-to) | 1483-1489 |

Number of pages | 7 |

Journal | Medical Physics |

Volume | 19 |

Issue number | 6 |

DOIs | |

State | Published - 1992 |

### Fingerprint

### Keywords

- calibration
- computer simulation
- gradient
- gradient switching
- magnetic resonance imaging (MRI)

### ASJC Scopus subject areas

- Biophysics

### Cite this

*Medical Physics*,

*19*(6), 1483-1489. https://doi.org/10.1118/1.596928

**A MRI gradient waveform model for automated sequence calibration.** / Barker, B. R.; Archer, B. T.; Erdman, W. A.; Peshock, Ronald M.

Research output: Contribution to journal › Article

*Medical Physics*, vol. 19, no. 6, pp. 1483-1489. https://doi.org/10.1118/1.596928

}

TY - JOUR

T1 - A MRI gradient waveform model for automated sequence calibration

AU - Barker, B. R.

AU - Archer, B. T.

AU - Erdman, W. A.

AU - Peshock, Ronald M

PY - 1992

Y1 - 1992

N2 - In order to set up magnetic resonance imaging (MRI) procedures of arbitrary voxel dimensions, slice orientation, and sequence timing in a reasonable time, some form of automatic gradient pulse calibration is required. One such method, involving simulation of gradient waveforms, is presented. Waveforms are modeled based on measurements of the step response. The model used divides each transition into three time regions: a 'start' region in the first 0.3 ms, a 'slew' region, and a 'tail' region representing decay of the eddy current compensation error. In the 'slew' region, the time derivative of the gradient, G'(t), is expressed as a function of G(t). The first two regions are nonlinear with respect to demand. The mean error in the simulated gradient is generally less than 0.04 mT m-1 in spin echo sequences. Image signal/noise ratios resulting from sequences calibrated using the model are within 5% of those of empirically calibrated sequences.

AB - In order to set up magnetic resonance imaging (MRI) procedures of arbitrary voxel dimensions, slice orientation, and sequence timing in a reasonable time, some form of automatic gradient pulse calibration is required. One such method, involving simulation of gradient waveforms, is presented. Waveforms are modeled based on measurements of the step response. The model used divides each transition into three time regions: a 'start' region in the first 0.3 ms, a 'slew' region, and a 'tail' region representing decay of the eddy current compensation error. In the 'slew' region, the time derivative of the gradient, G'(t), is expressed as a function of G(t). The first two regions are nonlinear with respect to demand. The mean error in the simulated gradient is generally less than 0.04 mT m-1 in spin echo sequences. Image signal/noise ratios resulting from sequences calibrated using the model are within 5% of those of empirically calibrated sequences.

KW - calibration

KW - computer simulation

KW - gradient

KW - gradient switching

KW - magnetic resonance imaging (MRI)

UR - http://www.scopus.com/inward/record.url?scp=0026490901&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026490901&partnerID=8YFLogxK

U2 - 10.1118/1.596928

DO - 10.1118/1.596928

M3 - Article

C2 - 1461213

AN - SCOPUS:0026490901

VL - 19

SP - 1483

EP - 1489

JO - Medical Physics

JF - Medical Physics

SN - 0094-2405

IS - 6

ER -