B小波和阶跃谱分析在缺损频谱成像中的应用

Application of B Wavelet and Step Spectrum Analysis in Truncated Data Imaging

提出一种用于频域的快速Ｂ小波变换方法和阶跃谱分析理论，并把它们用于磁共振缺损频谱数据中提取高频频谱、恢复完整频谱，重建图像．在此方法中，首先用快速Ｂ小波变换方法，从低频磁共振数据中提取、恢复缺少的高频分量的特征信息；然后用阶跃谱分析理论，由这些特征信息构成高频磁共振频谱、恢复完整频谱数据；最后用ＦＦＴ（ｆａｓｔＦｏｕｒｉｅｒｔｒａｎｓｆｏｒｍ）重建磁共振图像．实验和模拟结果都表明，重建图像质量优于现有方法．

In this paper, the authors propose a fast B wavelet transform method in spectrum domain and step spectrum analysis theory for extracting completed magnetic resonance(MR) spectrum data from the MR truncated data, and the reconstruction image. In this method, the feature information is abstracted from the available lowfrequency MR data using B wavelet method, and then highfrequency components are exerted from the feature information and whole spectrum data is recovered by using step spectrum analysis theory(SSAT), at last MR image is reconstructed from the recovered completed spectrum data by FFT(fast Fourier transform). Experiment and simulation results show that this method gives much better reconstructed image than the available method.