PMID- 21601552
OWN - NLM
STAT- MEDLINE
DCOM- 20111007
LR  - 20110613
IS  - 1876-861X (Electronic)
IS  - 1876-861X (Linking)
VI  - 5
IP  - 3
DP  - 2011 May-Jun
TI  - What is inverse-geometry CT?
PG  - 145-8
LID - 10.1016/j.jcct.2011.04.003 [doi]
AB  - Inverse-geometry computed tomography (IGCT) systems are being developed to 
      provide improved volumetric imaging. In conventional multislice CT systems, 
      x-rays are emitted from a small area and irradiate a large-area detector. In an 
      IGCT system, x-ray sources are distributed over a large area, with each beam 
      irradiating a small-area detector. Therefore, in the inverse geometry, a series 
      of narrow x-ray beams are switched on and off while the gantry rotates. In 
      conventional CT geometry, cone-beam and scatter artifacts increase with the 
      imaged volume thickness. An inverse geometry may be less susceptible to scatter 
      effects, because only a fraction of the field of view is irradiated at one time. 
      The distributed source in the inverse geometry potentially improves sampling, 
      leading to reduced cone-beam artifacts. In the inverse geometry, the tube current 
      may be adjusted separately for each source location, which potentially reduces 
      dose. Multiple IGCT prototypes have been constructed and tested on phantoms. A 
      gantry-based IGCT system with one-second gantry rotation was developed, and 
      images of phantoms and small animals were successfully acquired. Clinical 
      feasibility with acceptable noise levels and scan times has not yet been shown. 
      Overall, results from prototype systems suggest that the inverse geometry will 
      enable imaging of a thick volume ( approximately 16 cm) while potentially reducing cone-beam 
      artifacts, scatter effects, and radiation dose. The magnitude of these benefits 
      will depend on the specific IGCT implementation and need to be quantified 
      relative to comparable multislice scanners.
CI  - Copyright (c) 2011 Society of Cardiovascular Computed Tomography. Published by 
      Elsevier Inc. All rights reserved.
FAU - Schmidt, Taly Gilat
AU  - Schmidt TG
AD  - Department of Biomedical Engineering, Marquette University, PO Box 1881, 
      Milwaukee, WI 53201, USA. taly.gilat-schmidt@marquette.edu
LA  - eng
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Review
DEP - 20110416
PL  - United States
TA  - J Cardiovasc Comput Tomogr
JT  - Journal of cardiovascular computed tomography
JID - 101308347
SB  - IM
MH  - Animals
MH  - Artifacts
MH  - Equipment Design
MH  - Humans
MH  - Image Interpretation, Computer-Assisted
MH  - Phantoms, Imaging
MH  - Predictive Value of Tests
MH  - Radiation Dosage
MH  - Tomography, X-Ray Computed/instrumentation/*methods
EDAT- 2011/05/24 06:00
MHDA- 2011/10/08 06:00
CRDT- 2011/05/24 06:00
PHST- 2011/02/03 00:00 [received]
PHST- 2011/04/11 00:00 [accepted]
PHST- 2011/05/24 06:00 [entrez]
PHST- 2011/05/24 06:00 [pubmed]
PHST- 2011/10/08 06:00 [medline]
AID - S1934-5925(11)00174-2 [pii]
AID - 10.1016/j.jcct.2011.04.003 [doi]
PST - ppublish
SO  - J Cardiovasc Comput Tomogr. 2011 May-Jun;5(3):145-8. doi: 
      10.1016/j.jcct.2011.04.003. Epub 2011 Apr 16.