title: ACCURACY OF RADIOGRAPHIC DETECTION OF THE CRANIAL MARGIN OF THE DORSAL LAMINA OF THE CANINE SACRUM.
abstract: An elongated sacral lamina has been described as one of the contributing factors for dogs with cauda equina syndrome due to degenerative lumbosacral stenosis (DLSS); however, published evidence is lacking on the accuracy of radiographic screening for the presence of this lesion. Objectives of this prospective, cross-sectional cadaver study were to describe the accuracy and repeatability of detection of the cranial sacral lamina margin on plain lateral radiographs of the lumbosacral junction in dogs. Twenty-five medium and large breed canine cadavers were radiographed before and after placement of a radiopaque hook in the cranial margin of the sacral lamina. Three independent evaluators placed digital markers at the perceived margin on preinterventional radiographs. The distance from perceived location to the true location on postinterventional radiographs was recorded for each dog and observer. A discordance threshold (distance between perceived and actual margin) of 1.5 mm was subjectively defined as clinically relevant. The three evaluators demonstrated good repeatability, although the accuracy for margin detection was only fair (mean discordance 1.7 mm). Evaluators demonstrated greater accuracy in identifying the landmark in juveniles (1.4 mm) vs. adults (1.8 mm; P < 0.01). Results of this study indicated that observer repeatability is good and accuracy is fair for correctly identifying the radiographic cranial margin of the sacral lamina in dogs. This should be taken into consideration when interpreting elongation of the sacral lamina in radiographs of dogs with suspected DLSS, especially adults.
authors: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors: Lauren M
authors: LM
authors: Blume
authors: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors: Andrew J
authors: AJ
authors: Worth
authors: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors: Eli B
authors: EB
authors: Cohen
authors: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors: Janis P
authors: JP
authors: Bridges
authors: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors: Angela C
authors: AC
authors: Hartman
mesh_terms: D000367:Age Factors; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D000818:Animals; D002102:Cadaver; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000000981:diagnostic imaging; D004285:Dogs / Q000033:anatomy & histology*; D057918:Fiducial Markers; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data; D008161:Lumbosacral Region / Q000000981:diagnostic imaging; D015588:Observer Variation; D011128:Polyradiculopathy / Q000000981:diagnostic imaging / Q000662:veterinary; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods; D012447:Sacrum / Q000000981:diagnostic imaging*; D013115:Spinal Canal / Q000000981:diagnostic imaging*; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000662:veterinary
keywords: accuracy; canine; dorsal lamina; lumbosacral; radiograph