title: Inaccuracies in additive manufactured medical skull models caused by the DICOM to STL conversion process.
abstract: BACKGROUND
  The process of fabricating physical medical skull models requires many steps, each of which is a potential source of geometric error. The aim of this study was to demonstrate inaccuracies and differences caused by DICOM to STL conversion in additively manufactured medical skull models.
  
  
  METHODS
  Three different institutes were requested to perform an automatic reconstruction from an identical DICOM data set of a patients undergoing tumour surgery into an STL file format using their software of preference. The acquired digitized STL data sets were assessed and compared and subsequently used to fabricate physical medical skull models. The three fabricated skull models were then scanned, and differences in the model geometries were assessed using established CAD inspection software methods.
  
  
  RESULTS
  A large variation was noted in size and anatomical geometries of the three physical skull models fabricated from an identical (or "a single") DICOM data set.
  
  
  CONCLUSIONS
  A medical skull model of the same individual can vary markedly depending on the DICOM to STL conversion software and the technical parameters used. Clinicians should be aware of this inaccuracy in certain applications.
authors.affiliation: BIT Research Centre, Department of Industrial Engineering and Management, School of Science and Technology, Aalto University, P.O. Box 15500, FI-00076 Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Huotilainen
authors.affiliation: Oral and Maxillofacial Unit, Department of Otorhinolaryngology, Tampere University Hospital, P.O. Box 2000, FI-33521 Tampere, Finland; Medical Imaging Center, Department of Radiology, Tampere University Hospital, P.O. Box 2000, FI-33521 Tampere, Finland. Electronic address: risto.jaanimets@uta.fi.
authors.forename: Risto
authors.initials: R
authors.lastname: Jaanimets
authors.affiliation: Institute of Solid Mechanics, Mechatronics and Biomechanics, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Valášek
authors.affiliation: Institute of Solid Mechanics, Mechatronics and Biomechanics, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Marcián
authors.affiliation: BIT Research Centre, Department of Industrial Engineering and Management, School of Science and Technology, Aalto University, P.O. Box 15500, FI-00076 Helsinki, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Salmi
authors.affiliation: BIT Research Centre, Department of Industrial Engineering and Management, School of Science and Technology, Aalto University, P.O. Box 15500, FI-00076 Helsinki, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Tuomi
authors.affiliation: BIT Research Centre, Department of Industrial Engineering and Management, School of Science and Technology, Aalto University, P.O. Box 15500, FI-00076 Helsinki, Finland; Dept. of Otolaryngology - Head & Neck Surgery, Helsinki University Hospital and University of Helsinki, P.O. Box 220, FI-00029 Helsinki, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Mäkitie
authors.affiliation: Oral and Maxillofacial Unit, Department of Otorhinolaryngology, Tampere University Hospital, P.O. Box 2000, FI-33521 Tampere, Finland; Medical Imaging Center, Department of Radiology, Tampere University Hospital, P.O. Box 2000, FI-33521 Tampere, Finland.
authors.forename: Jan
authors.initials: J
authors.lastname: Wolff
mesh_terms: D000465:Algorithms; D002508:Cephalometry / Q000706:statistics & numerical data; D017076:Computer-Aided Design / Q000706:statistics & numerical data*; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data*; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D008334:Mandible / Q000033:anatomy & histology; D008443:Maxillary Sinus / Q000033:anatomy & histology; D008953:Models, Anatomic; D009296:Nasal Cavity / Q000033:anatomy & histology; D009915:Orbit / Q000033:anatomy & histology; D011873:Radiology Information Systems / Q000706:statistics & numerical data; D012886:Skull / Q000033:anatomy & histology*; D012984:Software; D013499:Surface Properties
keywords: Additive-manufacturing; Bio-modelling; CBCT; DICOM; STL