Dataset Information

Model predictive filtering MR thermometry: Effects of model inaccuracies, k-space reduction factor, and temperature increase rate.

ABSTRACT:

Purpose

Evaluate effects of model parameter inaccuracies (thermal conductivity, k, and ultrasound power deposition density, Q), k-space reduction factor (R), and rate of temperature increase ( T?) in a thermal model-based reconstruction for MR-thermometry during focused-ultrasound heating.

Methods

Simulations and ex vivo experiments were performed to investigate the accuracy of the thermal model and the model predictive filtering (MPF) algorithm for varying R and T?, and their sensitivity to errors in k and Q. Ex vivo data was acquired with a segmented EPI pulse sequence to achieve large field-of-view (192 × 162 × 96 mm) four-dimensional temperature maps with high spatiotemporal resolution (1.5 × 1.5 × 2.0 mm, 1.7 s).

Results

In the simulations, 50% errors in k and Q resulted in maximum temperature root mean square errors (RMSE) of 6 °C for model only and 3 °C for MPF. Using recently developed methods, estimates of k and Q were accurate to within 3%. The RMSE between MPF and true temperature increased with R and T?. In the ex vivo study the RMSE remained below 0.7 °C for R ranging from 4 to 12 and T? of 0.28-0.75 °C/s.

Conclusion

Errors in MPF temperatures occur due to errors in k and Q. These MPF temperature errors increase with increase in R and T?, but are smaller than those obtained using the thermal model alone.

SUBMITTER: Odeen H

PROVIDER: S-EPMC4549212 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

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Publications

Model predictive filtering MR thermometry: Effects of model inaccuracies, k-space reduction factor, and temperature increase rate.

Odéen Henrik H Todd Nick N Dillon Christopher C Payne Allison A Parker Dennis L DL

Magnetic resonance in medicine 20150225 1

<h4>Purpose</h4>Evaluate effects of model parameter inaccuracies (thermal conductivity, k, and ultrasound power deposition density, Q), k-space reduction factor (R), and rate of temperature increase ( T˙) in a thermal model-based reconstruction for MR-thermometry during focused-ultrasound heating.<h4>Methods</h4>Simulations and ex vivo experiments were performed to investigate the accuracy of the thermal model and the model predictive filtering (MPF) algorithm for varying R and T˙, and their sen ...[more]

PMID: 25726934

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Dataset Information

Model predictive filtering MR thermometry: Effects of model inaccuracies, k-space reduction factor, and temperature increase rate.

Purpose

Methods

Results

Conclusion

Publications

Model predictive filtering MR thermometry: Effects of model inaccuracies, k-space reduction factor, and temperature increase rate.

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