Effective voigt model estimation using multiple random starting values and parameter bounds settings for in vivo hepatic 1H magnetic resonance spectroscopic data

In vivo hepatic 1 H lineshapes modeled by the complex Voigt function are desirable to reduce systematic error and obtain accurate fits. However, the optimization procedure becomes challenging when the peak resonances overlap and the proportion of Gaussian to Lorentzian dampings is a priori unknown....

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Bibliographic Details
Main Authors: Ratiney, H., Bucur, A., Sdika, M., Beuf, O., Pilleul, F., Cavassila, S.
Format: Conference Proceeding
Language:English
Subjects:
Damping
Displays
Humans
In vivo
Magnetic resonance
Magnetic Resonance Spectroscopy
Mathematical model
Minimization methods
model parameter bounds
optimization
Robustness
Spectroscopy
starting values
Time domain analysis
Voigt Lineshape
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Description
Summary:In vivo hepatic 1 H lineshapes modeled by the complex Voigt function are desirable to reduce systematic error and obtain accurate fits. However, the optimization procedure becomes challenging when the peak resonances overlap and the proportion of Gaussian to Lorentzian dampings is a priori unknown. In this context, nonlinear least-squares algorithms generally invoked in Magnetic Resonance Spectroscopy quantification are highly sensitive to the starting values and parameter bounds. To alleviate this sensitivity, multiple random starting values and parameter bounds settings are used to generate candidate solutions. The "best fit" fulfilling requirements on the cost function and damping factor final values is then selected among them. Monte Carlo studies and an in vivo hepatic 1 H signal quantification demonstrated the relevance of the proposed strategy.
ISSN:1945-7928
1945-8452
DOI:10.1109/ISBI.2008.4541300