title: Evaluation of a 3D local multiresolution algorithm for the correction of partial volume effects in positron emission tomography.
abstract: OBJECTIVE
  Partial volume effects (PVEs) are consequences of the limited spatial resolution in emission tomography leading to underestimation of uptake in tissues of size similar to the point spread function (PSF) of the scanner as well as activity spillover between adjacent structures. Among PVE correction methodologies, a voxel-wise mutual multiresolution analysis (MMA) was recently introduced. MMA is based on the extraction and transformation of high resolution details from an anatomical image (MR/CT) and their subsequent incorporation into a low-resolution PET image using wavelet decompositions. Although this method allows creating PVE corrected images, it is based on a 2D global correlation model, which may introduce artifacts in regions where no significant correlation exists between anatomical and functional details.
  
  
  METHODS
  A new model was designed to overcome these two issues (2D only and global correlation) using a 3D wavelet decomposition process combined with a local analysis. The algorithm was evaluated on synthetic, simulated and patient images, and its performance was compared to the original approach as well as the geometric transfer matrix (GTM) method.
  
  
  RESULTS
  Quantitative performance was similar to the 2D global model and GTM in correlated cases. In cases where mismatches between anatomical and functional information were present, the new model outperformed the 2D global approach, avoiding artifacts and significantly improving quality of the corrected images and their quantitative accuracy.
  
  
  CONCLUSIONS
  A new 3D local model was proposed for a voxel-wise PVE correction based on the original mutual multiresolution analysis approach. Its evaluation demonstrated an improved and more robust qualitative and quantitative accuracy compared to the original MMA methodology, particularly in the absence of full correlation between anatomical and functional information.
authors: MRC Clinical Sciences Centre, Hammersmith Hospital Campus, Imperial College, London, UK.
authors: Adrien
authors: A
authors: Le Pogam
authors: Mathieu
authors: M
authors: Hatt
authors: Patrice
authors: P
authors: Descourt
authors: Nicolas
authors: N
authors: Boussion
authors: Charalampos
authors: C
authors: Tsoumpas
authors: Federico E
authors: FE
authors: Turkheimer
authors: Caroline
authors: C
authors: Prunier-Aesch
authors: Jean-Louis
authors: JL
authors: Baulieu
authors: Denis
authors: D
authors: Guilloteau
authors: Dimitris
authors: D
authors: Visvikis
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016014:Linear Models; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D051598:Whole Body Imaging