title: Multisource inverse-geometry CT. Part I. System concept and development.
abstract: OBJECTIVE
  This paper presents an overview of multisource inverse-geometry computed tomography (IGCT) as well as the development of a gantry-based research prototype system. The development of the distributed x-ray source is covered in a companion paper [V. B. Neculaes et al., "Multisource inverse-geometry CT. Part II. X-ray source design and prototype," Med. Phys. 43, 4617-4627 (2016)]. While progress updates of this development have been presented at conferences and in journal papers, this paper is the first comprehensive overview of the multisource inverse-geometry CT concept and prototype. The authors also provide a review of all previous IGCT related publications.
  
  
  METHODS
  The authors designed and implemented a gantry-based 32-source IGCT scanner with 22 cm field-of-view, 16 cm z-coverage, 1 s rotation time, 1.09 × 1.024 mm detector cell size, as low as 0.4 × 0.8 mm focal spot size and 80-140 kVp x-ray source voltage. The system is built using commercially available CT components and a custom made distributed x-ray source. The authors developed dedicated controls, calibrations, and reconstruction algorithms and evaluated the system performance using phantoms and small animals.
  
  
  RESULTS
  The authors performed IGCT system experiments and demonstrated tube current up to 125 mA with up to 32 focal spots. The authors measured a spatial resolution of 13 lp/cm at 5% cutoff. The scatter-to-primary ratio is estimated 62% for a 32 cm water phantom at 140 kVp. The authors scanned several phantoms and small animals. The initial images have relatively high noise due to the low x-ray flux levels but minimal artifacts.
  
  
  CONCLUSIONS
  IGCT has unique benefits in terms of dose-efficiency and cone-beam artifacts, but comes with challenges in terms of scattered radiation and x-ray flux limits. To the authors' knowledge, their prototype is the first gantry-based IGCT scanner. The authors summarized the design and implementation of the scanner and the authors presented results with phantoms and small animals.
authors.affiliation: CT Systems and Applications Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Bruno
authors.initials: B
authors.lastname: De Man
authors.affiliation: Functional Imaging Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Jorge
authors.initials: J
authors.lastname: Uribe
authors.affiliation: School of Integrated Technology, Yonsei University, Incheon 406-840, South Korea.
authors.forename: Jongduk
authors.initials: J
authors.lastname: Baek
authors.affiliation: CT Systems and Applications Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Dan
authors.initials: D
authors.lastname: Harrison
authors.affiliation: CT Systems and Applications Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Zhye
authors.initials: Z
authors.lastname: Yin
authors.affiliation: Mechanical Systems Technologies, GE Global Research, Niskayuna, New York 12309.
authors.forename: Randy
authors.initials: R
authors.lastname: Longtin
authors.affiliation: Mechanical Systems Technologies, GE Global Research, Niskayuna, New York 12309.
authors.forename: Jaydeep
authors.initials: J
authors.lastname: Roy
authors.affiliation: Design and Development Shops, GE Global Research, Niskayuna, New York 12309.
authors.forename: Bill
authors.initials: B
authors.lastname: Waters
authors.affiliation: High Energy Physics Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Colin
authors.initials: C
authors.lastname: Wilson
authors.affiliation: Detector Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Short
authors.affiliation: High Energy Physics Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Lou
authors.initials: L
authors.lastname: Inzinna
authors.affiliation: High Frequency Power Electronics Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Joseph
authors.initials: J
authors.lastname: Reynolds
authors.affiliation: High Energy Physics Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: V Bogdan
authors.initials: VB
authors.lastname: Neculaes
authors.affiliation: Mechanical Systems Technologies, GE Global Research, Niskayuna, New York 12309.
authors.forename: Kristopher
authors.initials: K
authors.lastname: Frutschy
authors.affiliation: Molecular Imaging and Computed Tomography, GE Healthcare, Waukesha, Wisconsin 53188.
authors.forename: Bob
authors.initials: B
authors.lastname: Senzig
authors.affiliation: Department of Radiology, Stanford University, Stanford, California 94305.
authors.forename: Norbert
authors.initials: N
authors.lastname: Pelc
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D002138:Calibration; D004867:Equipment Design; D019047:Phantoms, Imaging; D019904:Polymethyl Methacrylate; D011817:Rabbits; D011829:Radiation Dosage; D051381:Rats; D012542:Scattering, Radiation; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*; D014867:Water; D014965:X-Rays
chemical_list: D014867:Water; D019904:Polymethyl Methacrylate