liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Regularized iterative weighted filtered backprojection for helical cone-beam CT
Linköping University, The Institute of Technology. Linköping University, Department of Electrical Engineering.
Linköping University, The Institute of Technology. Linköping University, Department of Electrical Engineering.
2008 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 35, no 9, 4173-4185 p.Article in journal (Refereed) Published
Abstract [en]

Contemporary reconstruction methods employed for clinical helical cone-beam computed tomography (CT) are analytical (noniterative) but mathematically nonexact, i.e., the reconstructed image contains so called cone-beam artifacts, especially for higher cone angles. Besides cone artifacts, these methods also suffer from windmill artifacts: alternating dark and bright regions creating spiral-like patterns occurring in the vicinity of high z-direction derivatives. In this article, the authors examine the possibility to suppress cone and windmill artifacts by means of iterative application of nonexact three-dimensional filtered backprojection, where the analytical part of the reconstruction brings about accelerated convergence. Specifically, they base their investigations on the weighted filtered backprojection method [Stierstorfer et al., Phys. Med. Biol. 49, 2209-2218 (2004)]. Enhancement of high frequencies and amplification of noise is a common but unwanted side effect in many acceleration attempts. They have employed linear regularization to avoid these effects and to improve the convergence properties of the iterative scheme. Artifacts and noise, as well as spatial resolution in terms of modulation transfer functions and slice sensitivity profiles have been measured. The results show that for cone angles up to ±2.78°, cone artifacts are suppressed and windmill artifacts are alleviated within three iterations. Furthermore, regularization parameters controlling spatial resolution can be tuned so that image quality in terms of spatial resolution and noise is preserved. Simulations with higher number of iterations and long objects (exceeding the measured region) verify that the size of the reconstructible region is not reduced, and that the regularization greatly improves the convergence properties of the iterative scheme. Taking these results into account, and the possibilities to extend the proposed method with more accurate modeling of the acquisition process, the authors believe that iterative improvement with non-exact methods is a promising technique for medical CT applications.

Place, publisher, year, edition, pages
2008. Vol. 35, no 9, 4173-4185 p.
Keyword [en]
regularization, filtered backprojection, cone-beam CT, iterative reconstruction
National Category
Engineering and Technology
URN: urn:nbn:se:liu:diva-44874DOI: 10.1118/1.2966353Local ID: 78095OAI: diva2:265736
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2011-01-10

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Sunnegårdh, JohanDanielsson, Per-Erik
By organisation
The Institute of TechnologyDepartment of Electrical Engineering
In the same journal
Medical physics (Lancaster)
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 56 hits
ReferencesLink to record
Permanent link

Direct link