title: Accurate image reconstruction using real C-arm data from a Circle-plus-arc trajectory.
abstract: OBJECTIVE
  Developing an efficient tool for accurate three-dimensional imaging from projections measured with C-arm systems.
  
  
  METHODS
  A circle-plus-arc trajectory, which is complete and thus amenable to accurate reconstruction, is used. This trajectory is particularly attractive as its implementation does not require moving the patient. For reconstruction, we use the "M-line method", which allows processing the data in the efficient filtered backprojection mode. This method also offers the advantage of not requiring an ideal data acquisition geometry, i.e., the M-line algorithm can account for known deviations in the scanning geometry, which is important given that sizeable deviations are generally encountered in C-arm imaging.
  
  
  RESULTS
  A robust implementation scheme of the "M-line method" that applies straightforwardly to real C-arm data is presented. In particular, a numerically stable technique to compute the view-dependent derivative with respect to the source trajectory parameter is applied, and an efficient way to compute the π-line backprojection intervals via a polygonal weighting mask is presented. Projection data of an anthropomorphic thorax phantom were acquired on a medical C-arm scanner and used to demonstrate the benefit of using a complete data acquisition geometry with an accurate reconstruction algorithm versus using a state-of-the-art implementation of the conventional Feldkamp algorithm with a circular short scan of cone-beam data. A significant image quality improvement based on visual assessment is shown in terms of cone-beam artifacts.
authors: University of Erlangen-Nuremberg, Chair of Pattern Recognition, Erlangen, Germany. hoppe.stefan@online.de
authors: Stefan
authors: S
authors: Hoppe
authors: Joachim
authors: J
authors: Hornegger
authors: Frank
authors: F
authors: Dennerlein
authors: Günter
authors: G
authors: Lauritsch
authors: Frédéric
authors: F
authors: Noo
references: Med Phys. 2004 Jul;31(7):1972-5
references: 15305448
references: Comput Med Imaging Graph. 1999 Nov-Dec;23(6):311-21
references: 10634143
references: Phys Med Biol. 2000 Nov;45(11):3489-508
references: 11098919
references: Phys Med Biol. 2007 Sep 7;52(17):5393-414
references: 17762094
references: Phys Med Biol. 2005 May 21;50(10):2249-65
references: 15876665
references: Med Phys. 2008 Dec;35(12):5910-20
references: 19175146
references: Phys Med Biol. 2007 Dec 7;52(23):6943-60
references: 18029986
references: IEEE Trans Med Imaging. 2006 Jul;25(7):950-62
references: 16827495
references: Med Phys. 1982 Mar-Apr;9(2):254-7
references: 7087912
references: Med Phys. 2000 Apr;27(4):773-4
references: 10798699
references: IEEE Trans Med Imaging. 2000 May;19(5):391-403
references: 11021683
references: Phys Med Biol. 2004 Jun 7;49(11):2317-36
references: 15248580
references: Phys Med Biol. 2004 Nov 21;49(22):5059-72
references: 15609558
references: Phys Med Biol. 2003 Dec 7;48(23):3787-818
references: 14703159