Document Detail


Minimum detection windows, PI-line existence and uniqueness for helical cone-beam scanning of variable pitch.
MedLine Citation:
PMID:  15070255     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The goal of this paper is to study Cone-beam CT scanning along a helix of variable pitch. First the rationale and applications in medical imaging of variable pitch CT reconstruction are explained. Then formulas for the minimum detection window are derived. The main part of the paper proves a necessary and sufficient condition for the existence and uniqueness of PI-lines inside this variable pitch helix. These results are necessary steps toward an exact reconstruction algorithm for helix scanning of variable pitch, generalizing Katsevich's formula on constant pitch exact reconstruction. It is shown through an example that, when the derivative of the pitch function is not convex, or when the pitch function passes a inflection point and begins to slow down, PI-lines may be not unique near the rim of the helix cylinder. The conclusion is that the restriction on the pitch function is weaker, if the object is placed well within the helix cylinder and far from its rim, in order to preserve the uniqueness of PI-lines. If the object is near the rim, the restriction condition on the allowable pitch functions becomes stronger.
Authors:
Yangbo Ye; Jiehua Zhu; Ge Wang
Related Documents :
12105705 - Impact of multislice ct on pacs resources.
17710015 - Celiac plexus block: a new technique using the left lateral approach.
15305455 - The cause of the artifact in 4-slice helical computed tomography.
17285025 - Management of stones in calyceal diverticulum.
18356435 - Unenhanced mr angiography of the thoracic aorta: initial clinical evaluation.
15068145 - Mapping myocardial viability using interleaved t1-t2* weighted imaging.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Medical physics     Volume:  31     ISSN:  0094-2405     ISO Abbreviation:  Med Phys     Publication Date:  2004 Mar 
Date Detail:
Created Date:  2004-04-08     Completed Date:  2004-10-18     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0425746     Medline TA:  Med Phys     Country:  United States    
Other Details:
Languages:  eng     Pagination:  566-72     Citation Subset:  IM    
Affiliation:
Department of Mathematics, University of Iowa, Iowa City, Iowa 52242, USA. yangbo-ye@uiowa.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Angiography / methods*
Image Processing, Computer-Assisted / methods*
Models, Statistical
Models, Theoretical
Phantoms, Imaging
Tomography Scanners, X-Ray Computed
Tomography, X-Ray Computed / instrumentation,  methods*
Grant Support
ID/Acronym/Agency:
EB002667/EB/NIBIB NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Comparison of dual energy detector system performance.
Next Document:  Thermal and temporal response of ionization chambers in radiation dosimetry.