Noise reduction for cone-beam SPECT by penalized reweighted least-squares projection restoration

In single photon emission computed tomography(SPECT), the non-stationary Poisson noise in the projection data is one of the major degrading factors that jeopardize the quality of reconstructed images. In our previous researches for low-dose CT reconstruction, based on the noise properties of the log-transformed projection data, a penalized weighted least-squares (PWLS) cost function was constructed and the ideal projection data(i.e., line integral) was then estimated by minimizing the PWLS cost function. The experimental results showed the method could effectively suppress the noise without noticeable sacrifice of the spatial resolution for both fan- and cone-beam low-dose CT reconstruction. In this work, we tried to extend the PWLS projection restoration method to SPECT by redefining the weight term in PWLS cost function, because the weight is proportional to measured photon counts for transmission tomography (i.e., CT) while inversely proportional to measured photon counts for emission tomography (i.e., SPECT and PET). The iterative Gauss-Seidel algorithm was then used to minimize the cost function, and since the weight term was updated in each iteration, we refer our implementation as penalized reweighted least-squares (PRWLS) approach. The restorated projection data was then reconstructed by an analytical cone-beam SPECT reconstruction algorithm with compensation for non-uniform attenuation. Both high and low level Poisson noise was simulated in the cone-beam SPECT projection data, and the reconstruction results showed feasibility and efficacy of our proposed method on SPECT.

[1]  Xiaochuan Pan,et al.  Nonparametric regression sinogram smoothing using a roughness-penalized Poisson likelihood objective function , 2000, IEEE Transactions on Medical Imaging.

[2]  Zhengrong Liang,et al.  3D distance-weighted Wiener filter for Poisson noise reduction in sinogram space for SPECT imaging , 2001 .

[3]  M. Wernick,et al.  Emission Tomography: The Fundamentals of PET and SPECT , 2004 .

[4]  Zhengrong Liang,et al.  Towards analytical solution for 3D SPECT reconstruction with non- uniform attenuation and distance-dependent resolution variation : A monte carlo simulation study , 2002 .

[5]  M Defrise,et al.  Penalized maximum-likelihood sinogram restoration for dual focal spot computed tomography. , 2007, Physics in medicine and biology.

[6]  Jeffrey A. Fessler.  Tomographic Reconstruction Using Information-Weighted Spline Smoothing , 1993, IPMI.

[7]  Li Wang,et al.  Analytical Cone Beam SPECT Reconstruction with Non-Uniform Attenuation , 2009, 2009 3rd International Conference on Bioinformatics and Biomedical Engineering.

[8]  Zhengrong Liang,et al.  Dose reduction for kilovotage cone-beam computed tomography in radiation therapy. , 2008, Physics in medicine and biology.

[9]  Jing Wang,et al.  Penalized weighted least-squares approach to sinogram noise reduction and image reconstruction for low-dose X-ray computed tomography , 2006, IEEE Transactions on Medical Imaging.

[10]  Ken D. Sauer,et al.  A unified approach to statistical tomography using coordinate descent optimization , 1996, IEEE Trans. Image Process..

[11]  Hongbing Lu,et al.  Nonlinear sinogram smoothing for low-dose X-ray CT , 2004 .

[12]  Jeffrey A. Fessler,et al.  Statistical Sinogram Restoration in Dual-Energy CT for PET Attenuation Correction , 2009, IEEE Transactions on Medical Imaging.

[13]  Patrick J. La Rivière,et al.  Penalized-likelihood sinogram restoration for computed tomography , 2006, IEEE Transactions on Medical Imaging.

[14]  P. L. La Riviere.  Penalized-likelihood sinogram smoothing for low-dose CT. , 2005, Medical physics.

[15]  Hsiao Ing.  Analytical noise treatment for low-dose CT projection data by penalized weighted least-square smoothing in the K-L domain , 2002 .