title: An in vitro comparison of subjective image quality of panoramic views acquired via 2D or 3D imaging.
abstract: OBJECTIVE
  The objective of this study is to compare subjective image quality and diagnostic validity of cone-beam CT (CBCT) panoramic reformatting with digital panoramic radiographs.
  
  
  METHODS
  Four dry human skulls and two formalin-fixed human heads were scanned using nine different CBCTs, one multi-slice CT (MSCT) and one standard digital panoramic device. Panoramic views were generated from CBCTs in four slice thicknesses. Seven observers scored image quality and visibility of 14 anatomical structures. Four observers repeated the observation after 4 weeks.
  
  
  RESULTS
  Digital panoramic radiographs showed significantly better visualization of anatomical structures except for the condyle. Statistical analysis of image quality showed that the 3D imaging modalities (CBCTs and MSCT) were 7.3 times more likely to receive poor scores than the 2D modality. Yet, image quality from NewTom VGi® and 3D Accuitomo 170® was almost equivalent to that of digital panoramic radiographs with respective odds ratio estimates of 1.2 and 1.6 at 95% Wald confidence limits. A substantial overall agreement amongst observers was found. Intra-observer agreement was moderate to substantial.
  
  
  CONCLUSIONS
  While 2D-panoramic images are significantly better for subjective diagnosis, 2/3 of the 3D-reformatted panoramic images are moderate or good for diagnostic purposes.
  
  
  CONCLUSIONS
  Panoramic reformattings from particular CBCTs are comparable to digital panoramic images concerning the overall image quality and visualization of anatomical structures. This clinically implies that a 3D-derived panoramic view can be generated for diagnosis with a recommended 20-mm slice thickness, if CBCT data is a priori available for other purposes.
authors.affiliation: Oral Imaging Center, Department of Oral Health Sciences, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000, Leuven, Belgium. p.pittayapat@gmail.com
authors.forename: P
authors.initials: P
authors.lastname: Pittayapat
authors.forename: D
authors.initials: D
authors.lastname: Galiti
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.forename: K
authors.initials: K
authors.lastname: Dreesen
authors.forename: M
authors.initials: M
authors.lastname: Schreurs
authors.forename: P Couto
authors.initials: PC
authors.lastname: Souza
authors.forename: I R F
authors.initials: IR
authors.lastname: Rubira-Bullen
authors.forename: F H
authors.initials: FH
authors.lastname: Westphalen
authors.forename: R
authors.initials: R
authors.lastname: Pauwels
authors.forename: G
authors.initials: G
authors.lastname: Kalema
authors.forename: G
authors.initials: G
authors.lastname: Willems
authors.forename: R
authors.initials: R
authors.lastname: Jacobs
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000592:standards*; D005147:Facial Bones / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000592:standards; D021621:Imaging, Three-Dimensional / Q000592:standards*; D008334:Mandible / Q000000981:diagnostic imaging; D008335:Mandibular Condyle / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008443:Maxillary Sinus / Q000000981:diagnostic imaging; D061330:Multidetector Computed Tomography / Q000592:standards; D015588:Observer Variation; D010519:Periodontium / Q000000981:diagnostic imaging; D056739:Pterygopalatine Fossa / Q000000981:diagnostic imaging; D011856:Radiographic Image Enhancement / Q000592:standards*; D019252:Radiography, Dental, Digital / Q000592:standards*; D011862:Radiography, Panoramic / Q000592:standards*; D012886:Skull / Q000000981:diagnostic imaging; D014070:Tooth / Q000000981:diagnostic imaging