Estimation Accuracy of HR delay in ER-fMRI Using Wavelet Transform

Abstract

Investigating the shape and time to peak (HR delay) of hemodynamic response (HR) introduces a new facet of researches on human brain function. We have proposed an analysis method for detecting activated areas and measuring HR delay simultaneously using event related function magnetic resonance images (ER-fMRI). The method has been based on wavelet transform. In this paper, we investigate the performance of the method by modifying a mother wavelet. The modified mother wavelet is based on mathematically defined HR function by SPM (statistic parametric mapping) software by Friston et al. To evaluate the proposed method, we applied the proposed method and conventional methods to the phantom data. The results showed that the method could detect the activated area equivalent to and more than conventional methods. We also estimated the accuracy of measuring HR delay. The results showed that the proposed method could measure HR delay more accurate than the conventional method.