PMID- 19291978
OWN - NLM
STAT- MEDLINE
DCOM- 20090408
LR  - 20211020
IS  - 0094-2405 (Print)
IS  - 0094-2405 (Electronic)
IS  - 0094-2405 (Linking)
VI  - 36
IP  - 2
DP  - 2009 Feb
TI  - Direct two-dimensional reconstruction algorithm for an inverse-geometry CT 
      system.
PG  - 394-401
AB  - An inverse-geometry computed tomography (IGCT) system uses a large source array 
      opposite a smaller detector array. A previously described IGCT reconstruction 
      algorithm uses gridding, but this gridding step produces blurring in the 
      reconstructed image. In this article, the authors describe a two-dimensional (2D) 
      IGCT reconstruction algorithm without gridding. In the transverse direction, the 
      raw data of the IGCT system can be viewed as being composed of many fan beams. 
      Because the spacing between source spots is larger than the spot width, each fan 
      beam has undersampled projection data, but the missing samples are effectively 
      provided by other undersampled fan beam views. In the proposed method, a direct 
      fan beam reconstruction algorithm is used to process each undersampled fan beam. 
      Initial images with this method showed ring artifacts caused by nonuniform 
      sampling in the radial direction as compared to an ideal fan beam. A new method 
      for correcting this effect was developed. With this correction, high quality 
      images were obtained. The noise performance of the proposed 2D IGCT 
      reconstruction algorithm was investigated, and it was comparable to that of the 
      fan beam system. A MTF study showed that the proposed method achieves better 
      resolution than the gridding method.
FAU - Baek, Jongduk
AU  - Baek J
AD  - Department of Radiology, Stanford University, Stanford, California 94305, USA. 
      bjd1219@stanford.edu
FAU - Pelc, Norbert J
AU  - Pelc NJ
LA  - eng
GR  - R01 EB006837/EB/NIBIB NIH HHS/United States
GR  - EB6837/EB/NIBIB NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
SB  - IM
MH  - *Algorithms
MH  - Computer Simulation
MH  - Image Processing, Computer-Assisted/*methods
MH  - Models, Biological
MH  - Phantoms, Imaging
MH  - Tomography, X-Ray Computed/*methods
PMC - PMC2673672
EDAT- 2009/03/19 09:00
MHDA- 2009/04/09 09:00
PMCR- 2010/02/01
CRDT- 2009/03/19 09:00
PHST- 2009/03/19 09:00 [entrez]
PHST- 2009/03/19 09:00 [pubmed]
PHST- 2009/04/09 09:00 [medline]
PHST- 2010/02/01 00:00 [pmc-release]
AID - 012902MPH [pii]
AID - 10.1118/1.3050160 [doi]
PST - ppublish
SO  - Med Phys. 2009 Feb;36(2):394-401. doi: 10.1118/1.3050160.