title: Magnetic resonance imaging (MRI) spinal cord and canal measurements in normal dogs.
abstract: The goal of this study was to establish Magnetic resonance imaging (MRI) reference ranges for spinal measurements in normal dogs. Forty dogs (1-10 kg, 11-20 kg, 21-30 kg, > 30 kg; 10 dogs per category) underwent spinal MRI. Measurements were performed on sagittal T2-W images at the level of the 4th thoracic vertebra (T4), the 9th thoracic vertebra (T9) and the 3rd lumbar vertebra (L3). Spinal canal diameter (mm) ranged from 6.07 ± 0.63 (1-10 kg) to 8.27 ± 1.15 (> 30 kg) at the level of T4; 6.55 ± 0.61 (1-10 kg) to 9.04 ± 1.26 (> 30 kg) at the level of T9; and 6.80 (6.47-7.00; 1-10 kg) to 9.00 (7.90-9.73; > 30 kg) at the level of L3. There were significant differences (P < 0.05) in spinal canal diameter between groups. Mean spinal cord diameter (mm) ranged from 4.46 ± 0.51 (11-20 kg) to 4.70 ± 0.35 (1-10 kg) at the level of T4; 4.41 ± 0.50 (> 30 kg) to 4.85 ± 0.57 (1-10 kg) at the level of T9; and 4.52 ± 0.51 (> 30 kg) to 5.14 ± 0.68 (1-10 kg) at the level of L3. There were no significant differences in spinal cord diameter between groups. Spinal cord-to-spinal canal ratio varied significantly, ranging from 0.51 ± 0.08 (> 30 kg at L3) to 0.78 (0.69-0.80; 1-10 kg at T4) (P < 0.05). These findings are important when using MRI to evaluate patients with suspected diffuse spinal cord disease.
authors.affiliation: Department of Small Animal Clinical Sciences, University of Tennessee College of Veterinary Medicine, 2407 River Drive, Knoxville, TN, 37996, USA.
authors.forename: S
authors.initials: S
authors.lastname: Hecht
authors.forename: M M
authors.initials: MM
authors.lastname: Huerta
authors.forename: R B
authors.initials: RB
authors.lastname: Reed
mesh_terms: D000818:Animals; D004285:Dogs / Q000033:anatomy & histology*; D005260:Female; D008159:Lumbar Vertebrae / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D012016:Reference Values; D013115:Spinal Canal / Q000033:anatomy & histology*; D013116:Spinal Cord / Q000033:anatomy & histology*; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000662:veterinary