title: [Correlation of examination couch position and height with image registration accuracy in an effective field of vision of SPECT/CT].
abstract: OBJECTIVE
  To explore the correlation of the position and height of the examination couch with the accuracy of image registration in an exact effective field of vision (FOV) of single photon emission computed tomography/computed tomography (SPECT/CT) and determine the optimal position of the examination couch for best image registration.
  
  
  METHODS
  The tests were performed on a SPECT/CT with 6 radioactive (153)Gd sources in 3 groups (two in each group with energy peak of 40.9 Kev, 41.54 Kev, and 103.18 Kev) in an assorted standard pattern. Thirteen groups of slice data were obtained by changing the position and height of the bed but keeping the tomograpy slice constant. The bias of the accuracy of image registration was acquired using ALIGNMENT software and compared for different examination couch positions and heights.
  
  
  RESULTS
  The position of the examination couch at 0 cm in the Z axis and -4 cm in the Y axis showed the least error of image registration.
  
  
  CONCLUSIONS
  To achieve optimal SPECT and CT image fusion, quality control must be implemented and calibration of image registration accuracy should be done when necessary.
authors.affiliation: Department of Nuclear Medincine, Guangdong General Hospital, Guangdong Academy of Medical Science, Guangzhou 510080, China.E-mail: hu_zhihui_ect@126.com.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Hu
authors.forename: Siyun
authors.initials: S
authors.lastname: Qwang
authors.forename: Shuxia
authors.initials: S
authors.lastname: Wang
authors.forename: Linbo
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D006801:Humans; D007089:Image Enhancement; D056888:Patient Positioning; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon