title: Non-local means resolution enhancement of lung 4D-CT data.
abstract: Image resolution in 4D-CT is a crucial bottleneck that needs to be overcome for improved dose planning in radiotherapy for lung cancer. In this paper, we propose a novel patch-based algorithm to enhance the image quality of 4D-CT data. Our premise is that anatomical information missing in one phase can be recovered from complementary information embedded in other phases. We employ a patch-based mechanism to propagate information across phases for reconstruction of intermediate slices in the axial direction, where resolution is normally the lowest. Specifically, structurally-matching and spatially-nearby patches are combined for reconstruction of each patch. For greater sensitivity to anatomical nuances, we further employ a quad-tree technique to adaptively partition each slice of the image in each phase for more fine-grained refinement. Our evaluation based on a public 4D-CT lung data indicates that our algorithm gives very promising results with significantly enhanced image structures.
authors.affiliation: School of Biomedical Engineering, Southern Medical University, Guang Zhou, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guorong
authors.initials: G
authors.lastname: Wu
authors.forename: Pew-Thian
authors.initials: PT
authors.lastname: Yap
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Feng
authors.forename: Jun
authors.initials: J
authors.lastname: Lian
authors.forename: Wufan
authors.initials: W
authors.lastname: Chen
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000465:Algorithms; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008953:Models, Anatomic; D015233:Models, Statistical; D011857:Radiographic Image Interpretation, Computer-Assisted; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*