Optimization of single voxel MR spectroscopy sequence parameters and data analysis methods for thermometry in deep hyperthermia treatments

• Verfasst von: Hartmann, Josefin [VerfasserIn]
• Verfasst von: Pyatykh, Stanislav [VerfasserIn]
• Verfasst von: Hesser, Jürgen [VerfasserIn]
• Titel: Optimization of single voxel MR spectroscopy sequence parameters and data analysis methods for thermometry in deep hyperthermia treatments
• Verf.angabe: 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
• Jahr: 2017
• Jahr des Originals: 2016
• Umfang: 12 S.
• Fussnoten: Gesehen am 25.07.2018 ; First Published July 14, 2016
• Titel Quelle: Enthalten in: Technology in cancer research & treatment
• Ort Quelle: Thousand Oaks, CA : Sage Publishing, 2002
• Jahr Quelle: 2017
• Band/Heft Quelle: 16(2017), 4, Seite 470-481
• ISSN Quelle: 1533-0338
• DOI: doi:10.1177/1533034616656310
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1577918649

Abstract

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.