title: Quality of preimplant low-dose tomography.
abstract: OBJECTIVE
  The aim of this study was to test the influence of radiation dose on image quality in mandibular preimplant computed tomographic examinations and to compare the quality of computed and conventional spiral tomographic images.
  
  
  METHODS
  Cross-sectional images were obtained on 17 patients with conventional spiral tomography (Scanora technique) and reformatted computed tomography at 40 and 80 mAs. Observers graded the acceptability of images for implant planning and traced the contour of the mandibular body and canal.
  
  
  RESULTS
  Conventional spiral tomographic images scored significantly higher than computed tomographic images whereas mean score differences between computed tomographic techniques were not statistically significant. Anatomic structures, in particular the mandibular canal, were more frequently untraceable in high-dose than in low-dose computed tomography but always traceable in conventional tomograms.
  
  
  CONCLUSIONS
  Conventional spiral tomograms were subjectively preferred over computed tomographic images. For mandibular implant planning, computed tomography examinations can be performed with lower-than-standard mAs. Quantum noise seems to contribute to the visibility of anatomic structures in reformatted computed tomographic images.
authors.affiliation: Department of Oral Diagnostic Radiology, Göteborg University, Faculty of Odontology, Sweden. ekestubbe@odontologi.gu.se
authors.forename: A
authors.initials: A
authors.lastname: Ekestubbe
authors.forename: K
authors.initials: K
authors.lastname: Gröndahl
authors.forename: H G
authors.initials: HG
authors.lastname: Gröndahl
mesh_terms: D000328:Adult; D000368:Aged; D003757:Dental Implantation; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008875:Middle Aged; D015588:Observer Variation; D010347:Patient Care Planning; D011786:Quality Control; D011829:Radiation Dosage; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data