title: Use of computed tomographic densitometry to quantify contrast enhancement of compressive soft tissues in the canine lumbosacral vertebral canal.
abstract: OBJECTIVE
  To evaluate computed tomography (CT) densitometry as a technique for quantifying contrast enhancement of compressive soft tissues in the canine lumbosacral vertebral canal and to determine whether the degree of contrast enhancement can be used to help predict tissue type or histopathologic characteristics.
  
  
  METHODS
  29 large breed dogs with lumbosacral stenosis.
  
  
  METHODS
  Contrast-enhanced CT of L5-S3 was performed by use of a previously described protocol. At each disk level, CT densities of a water-filled syringe, epaxial muscles, and 4 vertebral canal locations were measured. Mean tissue enhancement was calculated by vertebral canal location, using water-filled syringe enhancement as a correction factor. Corrected CT enhancement was compared with tissue type, degree of tissue inflammation, and degree of tissue activity.
  
  
  RESULTS
  Intravenous contrast administration of contrast medium significantly increased CT densities of water-filled syringes and epaxial muscles. Corrected CT enhancement of vertebral canal soft tissues at stenotic sites was greater than at nonstenotic sites. There was no association between enhancement and tissue type for any vertebral canal location. There was no correlation between enhancement and degree of tissue inflammation. There was a correlation between enhancement and tissue activity in the dorsal vertebral canal only.
  
  
  CONCLUSIONS
  A water-filled syringe is a useful calibration tool for CT density measurements. The degree of tissue contrast enhancement, measured by CT densitometry, can be helpful for predicting the location of compressive soft tissues in dogs with lumbosacral stenosis. However, it is of limited value for predicting compressive soft-tissue types or histopathologic characteristics.
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg 24061, USA.
authors.forename: Jeryl C
authors.initials: JC
authors.lastname: Jones
authors.forename: Peter K
authors.initials: PK
authors.lastname: Shires
authors.forename: Karen D
authors.initials: KD
authors.lastname: Inzana
authors.forename: Adina D
authors.initials: AD
authors.lastname: Mosby
authors.forename: D Philip
authors.initials: DP
authors.lastname: Sponenberg
authors.forename: Otto I
authors.initials: OI
authors.lastname: Lanz
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D004285:Dogs; D008161:Lumbosacral Region; D011446:Prospective Studies; D013115:Spinal Canal / Q000473:pathology / Q000601:surgery; D013130:Spinal Stenosis / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary*
chemical_list: D003287:Contrast Media