Feldkamp-type cone-beam tomography in the wavelet framework.
X-ray computed tomography (CT) is in transition from fan-beam to cone-beam geometry. For cone-beam volumetric imaging, reduction of radiation exposure remains an important issue. Because the wavelet approach was shown to be effective and flexible for two-dimensional (2-D) local region reconstruction, we are motivated to perform wavelet local CT in cone-beam geometry. In this paper, we formulate the Feldkamp cone-beam reconstruction from the wavelet perspective, derive both full-scan and half-scan Feldkamp-type formulas for either global or local reconstruction, and demonstrate the feasibility and utility in synthetic and real data. It is found that using the wavelet Feldkamp approach, a three-dimensional (3-D) region of interest (ROI) can be reconstructed with neither severe image artifacts nor any significant constant bias in our simulation and experiments.
Zhao
S
S
Department of Mathematics and Computer Science, University of Missouri-St. Louis 63121, USA. zhao@great-wall.umsl.edu
Wang
G
G
D000818:Animals; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D051379:Mice; D019047:Phantoms, Imaging; D051381:Rats; D014057:Tomography, X-Ray Computed / Q000379:methods