title: Acquisition, preprocessing, and reconstruction of ultralow dose volumetric CT scout for organ-based CT scan planning.
abstract: OBJECTIVE
  Traditionally, 2D radiographic preparatory scan images (scout scans) are used to plan diagnostic CT scans. However, a 3D CT volume with a full 3D organ segmentation map could provide superior information for customized scan planning and other purposes. A practical challenge is to design the volumetric scout acquisition and processing steps to provide good image quality (at least good enough to enable 3D organ segmentation) while delivering a radiation dose similar to that of the conventional 2D scout.
  
  
  METHODS
  The authors explored various acquisition methods, scan parameters, postprocessing methods, and reconstruction methods through simulation and cadaver data studies to achieve an ultralow dose 3D scout while simultaneously reducing the noise and maintaining the edge strength around the target organ.
  
  
  RESULTS
  In a simulation study, the 3D scout with the proposed acquisition, preprocessing, and reconstruction strategy provided a similar level of organ segmentation capability as a traditional 240 mAs diagnostic scan, based on noise and normalized edge strength metrics. At the same time, the proposed approach delivers only 1.25% of the dose of a traditional scan. In a cadaver study, the authors' pictorial-structures based organ localization algorithm successfully located the major abdominal-thoracic organs from the ultralow dose 3D scout obtained with the proposed strategy.
  
  
  CONCLUSIONS
  The authors demonstrated that images with a similar degree of segmentation capability (interpretability) as conventional dose CT scans can be achieved with an ultralow dose 3D scout acquisition and suitable postprocessing. Furthermore, the authors applied these techniques to real cadaver CT scans with a CTDI dose level of less than 0.1 mGy and successfully generated a 3D organ localization map.
authors.affiliation: Image Reconstruction Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Zhye
authors.initials: Z
authors.lastname: Yin
authors.affiliation: X-ray and CT Laboratory, GE Global Research, Shanghai 201203, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Biomedical Image Processing Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Albert
authors.initials: A
authors.lastname: Montillo
authors.affiliation: X-ray and CT Laboratory, GE Global Research, Shanghai 201203, China.
authors.forename: Mingye
authors.initials: M
authors.lastname: Wu
authors.affiliation: CT, X-ray and Functional Imaging, GE Global Research, Niskayuna, New York 12309.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Edic
authors.affiliation: Thoracic and Cardiac Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114.
authors.forename: Mannudeep
authors.initials: M
authors.lastname: Kalra
authors.affiliation: Image Reconstruction Laboratory, GE Global Research, Niskayuna, New York 12309.
authors.forename: Bruno
authors.initials: B
authors.lastname: De Man
mesh_terms: D000465:Algorithms; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011860:Radiography, Abdominal / Q000295:instrumentation / Q000379:methods; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods