title: [Computed tomography imaging of the temporomandibular joint in dogs and cats. Effects of different scan parameters on image quality].
abstract: OBJECTIVE
  Temporomandibular joints (TMJs) of dogs and cats were examined with multislice computed tomography (MSCT) using different technical scan parameters in order to investigate their impact on image quality. Another aspect was to analyze whether size differences of the TMJ affect the display of small joint structures.
  
  
  METHODS
  The TMJs of two dogs and two cats were examined using MSCT. Scan parameters were varied including tube current, scan matrix, resolution mode, slice thickness, and reconstruction increment. Three observers being blinded with respect to the used scan parameters independently assessed the image quality in terms of "contrast resolution", "bone structure", "spatial resolution", "evaluation of the joint space", and "artefacts" according to a 4-point scale.
  
  
  RESULTS
  The criteria "spatial resolution" and "evaluation of the joint space" emphasize the influence of the size of the TMJ. The image quality of the TMJ of the dogs was evaluated superior (by 0.5 to 1.5 points higher graded) compared to the smaller ones of the cats. In terms of "spatial resolution" and "bone structure" the images of an ultra high resolution technique achieved a higher evaluation level (scoring one point superior) compared to the images created by a high resolution protocol. The tube current did not significantly influence the image quality in any of the pictures.
  
  
  CONCLUSIONS
  The display quality of small structures of the TMJ is dependent on the spatial resolution of the CT images. Therefore, a thin slice collimation, a small field of view, and a high resolution reconstruction matrix should be used. Under those aspects subtle alterations of bone structure of the TMJ can be reliably detected. The soft tissue structures of the TMJ can not be visualized with MSCT in small animals. In principle, the results can be applied to any other MSCT-scanner. However, adjustments of the technical parameters may be still necessary.
authors.affiliation: Klinik für Kleintiere, der Universität Leipzig, An den Tierkliniken 23, 04103 Leipzig. gaebler@kleintierklinik.uni-leipzig.de
authors.forename: K
authors.initials: K
authors.lastname: Gäbler
authors.forename: A
authors.initials: A
authors.lastname: Brühschwein
authors.forename: I
authors.initials: I
authors.lastname: Kiefer
authors.forename: S
authors.initials: S
authors.lastname: Loderstedt
authors.forename: G
authors.initials: G
authors.lastname: Oechtering
authors.forename: E
authors.initials: E
authors.lastname: Ludewig
mesh_terms: D000818:Animals; D002415:Cats / Q000033:anatomy & histology*; D004285:Dogs / Q000033:anatomy & histology*; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards / Q000662:veterinary*