suitability of bilateral filtering for edge-preserving noise reduction in pet适用性edge-preserving降噪双边滤波的宠物.pdf

Hofheinz et al. EJNMMI Research 2011, 1:23 /content/1/1/23 ORIGINAL RESEARCH Open Access Suitability of bilateral filtering for edge-preserving noise reduction in PET 1* 1 1,2 2 1 1,2 Frank Hofheinz , Jens Langner , Bettina Beuthien-Baumann , Liane Oehme , Jörg Steinbach , Jörg Kotzerke and Jörg van den Hoff1,2 Abstract Background: To achieve an acceptable signal-to-noise ratio (SNR) in PET images, smoothing filters (SF) are usually employed during or after image reconstruction preventing utilisation of the full intrinsic resolution of the respective scanner. Quite generally Gaussian-shaped moving average filters (MAF) are used for this purpose. A potential alternative to MAF is the group of so-called bilateral filters (BF) which provide a combination of noise reduction and edge preservation thus minimising resolution deterioration of the images. We have investigated the performance of this filter type with respect to improvement of SNR, influence on spatial resolution and for derivation of SUVmax values in target structures of varying size. Methods: Data of ten patients with head and neck cancer were evaluated. The patients had been investigated by routine whole body scans (ECAT EXACT HR+, Siemens, Erlangen). Tomographic images were reconstructed (OSEM 6i/16s) using a Gaussian filter (full width half maximum (FWHM): Γ0 = 4 mm). Image data were then post- processed with a Gaussian MAF (FWHM: ΓM = 7 mm) and a Gaussian BF (spatial domain: ΓS = 9 mm, intensity domain: ΓI = 2.5 SUV), respectively. Images were assessed regarding SNR as well as spatial resolution. Thirty-four lesions (volumes of about 1-100 mL) were analysed with respect to their SUVmax values in the origin