Optimization of single voxel MR spectroscopy sequence parameters and data analysis methods for thermometry in deep hyperthermia treatments
Objective:The difference in the resonance frequency of water and methylene moieties of lipids quantifies in magnetic resonance spectroscopy the absolute temperature using a predefined calibration curve. The purpose of this study was the investigation of peak evaluation methods and the magnetic reson...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2017
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| In: |
Technology in cancer research & treatment
Year: 2016, Volume: 16, Issue: 4, Pages: 470-481 |
| ISSN: | 1533-0338 |
| DOI: | 10.1177/1533034616656310 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1177/1533034616656310 Verlag, kostenfrei, Volltext: https://doi.org/10.1177/1533034616656310 
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| Author Notes: | J. Hartmann, MSc, J. Gellermann, MD, T. Brandt, MSc, M. Schmidt, PhD, S. Pyatykh, PhD, J. Hesser, PhD, O. Ott, MD, R. Fietkau, MD, and C. Bert, PhD |
| Summary: | Objective:The difference in the resonance frequency of water and methylene moieties of lipids quantifies in magnetic resonance spectroscopy the absolute temperature using a predefined calibration curve. The purpose of this study was the investigation of peak evaluation methods and the magnetic resonance spectroscopy sequence (point-resolved spectroscopy) parameter optimization that enables thermometry during deep hyperthermia treatments.Materials and Methods:Different Lorentz peak-fitting methods and a peak finding method using singular value decomposition of a Hankel matrix were compared. Phantom measurements on organic substances (mayonnaise and pork) were performed inside the hyperthermia 1.5-T magnetic resonance imaging system for the parameter optimization study. Parameter settings such as voxel size, echo time, and flip angle were varied and investigated.Results:Usually all peak analyzing methods were applicable. Lorentz peak-fitting method in MATLAB proved to be the most stable regardless of the number of fitted peaks, yet the slowest method. The examinations yielded an optimal parameter combination of 8 cm3 voxel volume, 55 millisecond echo time, and a 90° excitation pulse flip angle.Conclusion:The Lorentz peak-fitting method in MATLAB was the most reliable peak analyzing method. Measurements in homogeneous and heterogeneous phantoms resulted in optimized parameters for the magnetic resonance spectroscopy sequence for thermometry. |
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| Item Description: | Gesehen am 25.07.2018 First Published July 14, 2016 |
| Physical Description: | Online Resource |
| ISSN: | 1533-0338 |
| DOI: | 10.1177/1533034616656310 |