Title :
A nonlinear, image domain filtering method for cardiac PET images
Author :
Farquhar, T.H. ; Chinn, G. ; Hoh, C.K. ; Huang, S.C. ; Hoffman, E.J.
Author_Institution :
Div. of Nucl. Med. & Biophys., California Univ., Los Angeles, CA, USA
fDate :
8/1/1998 12:00:00 AM
Abstract :
An adaptive, nonlinear image domain filtering strategy is described which improves positron emission tomography (PET) images. The method was formulated to improve on the linear, low-pass filtering typically applied to each projection in the filtered back-projection (FBP) reconstruction algorithm. The algorithm is a potential alternative to linear smoothing which reduces noise but degrades resolution; this method uses the FBP algorithm for reconstruction, but aims to incorporate some of the statistical information and nonlinear smoothing utilized in iterative reconstruction algorithms. The approach uses sinogram segmentation to separate the sinogram elements with higher and lower signal-to-noise ratios, and then reconstruct each with FBP using a more appropriate choice of filter and cut-off frequency. Also, this algorithm addresses the radial streak artifacts introduced by FBP. The algorithm was evaluated using simulations clinical data of cardiac PET studies on an ECAT 931 PET scanner. The initial results suggest that this technique has advantages over the current clinical protocol. Images processed with the method show generally improved visual image quality and reduced radial streaks without the introduction of artifacts. In simulations, increased contrast recovery and resolution are realized without an increase in the background noise of the reconstructed images
Keywords :
adaptive signal processing; cardiology; image reconstruction; image resolution; image segmentation; iterative methods; medical image processing; positron emission tomography; ECAT 931 PET scanner; adaptive nonlinear image domain filtering strategy; background noise; cardiac PET images improvement; cut-off frequency; linear smoothing; medical diagnostic imaging; nonlinear image domain filtering method; nonlinear smoothing; nuclear medicine; radial streak artifacts; signal-to-noise ratio; sinogram elements; sinogram segmentation; statistical information; Adaptive filters; Filtering; Image reconstruction; Iterative algorithms; Low pass filters; Noise reduction; Nonlinear filters; Positron emission tomography; Reconstruction algorithms; Smoothing methods;
Journal_Title :
Nuclear Science, IEEE Transactions on