## Abstract

Thermal safety indices for diagnostic ultrasound beams are calculated

under the assumption that the sound propagates under linear

conditions. A non-axisymmetric finite difference model is used to

solve the KZK equation, and so to model the beam of a diagnostic

scanner in pulsed Doppler mode. Beams from both a uniform focused

rectangular source and a linear array are considered. Calculations are

performed in water, and in attenuating media with tissue-like

characteristics. Attenuating media are found to exhibit significant

nonlinear effects for finite-amplitude beams. The resulting loss of

intensity by the beam is then used as the source term in a model of

tissue heating to estimate the maximum temperature rises. These are

compared with the thermal indices, derived from the properties of the

water-propagated beams.

under the assumption that the sound propagates under linear

conditions. A non-axisymmetric finite difference model is used to

solve the KZK equation, and so to model the beam of a diagnostic

scanner in pulsed Doppler mode. Beams from both a uniform focused

rectangular source and a linear array are considered. Calculations are

performed in water, and in attenuating media with tissue-like

characteristics. Attenuating media are found to exhibit significant

nonlinear effects for finite-amplitude beams. The resulting loss of

intensity by the beam is then used as the source term in a model of

tissue heating to estimate the maximum temperature rises. These are

compared with the thermal indices, derived from the properties of the

water-propagated beams.

Original language | English |
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Pages | 483-486 |

Number of pages | 4 |

Publication status | Published - 2000 |

Event | 15th International Symposium on Nonlinear Acoustics - Goettingen Duration: 1 Sept 1999 → 4 Sept 1999 |

### Conference

Conference | 15th International Symposium on Nonlinear Acoustics |
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City | Goettingen |

Period | 1/09/99 → 4/09/99 |

### Bibliographical note

The Effect of Nonlinear Propagation on Heating of Tissue: A Numerical Model of Diagnostic Ultrasound Beams, M.D. Cahill, V.F. Humphrey and C. Doody, proceedings of the 15th International Symposium on Nonlinear Acoustics, Goettingen, Ed. W. Lauterborn and T. Kurtz, pp 483-486 (2000).## Keywords

- Nonlinear Propagation of Ultrasound
- Heating of Tissue