Evaluation of canine intervertebral disc degeneration in colour-coded computed tomography

Irish Veterinary Journal

Patrick Wefstaedt³  Ingo Nolte³  Martin Beyerbach²  Vladimir Galindo-Zamora¹  Lisa K. Harder³ 

[1] Small Animal Clinic, Faculty of Veterinary Medicine, National University of Colombia, Carrera 30 45-03 (Ciudad Universitaria), Bogotá, Colombia;Institut for Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Foundation, Bünteweg 2, Hannover, D-30559, Germany;Small Animal Hospital, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, Hannover, D-30559, Germany

关键词: Magnetic resonance imaging;    Comparison;    Classification;    Intervertebral disc degeneration;    Colour;    Canine;    Dog;    Computed tomography;   

Others  :  1232632
DOI  :  10.1186/s13620-015-0054-1

 received in 2015-01-15, accepted in 2015-11-05,  发布年份 2015

【 摘 要 】

Background

Canine intervertebral disc degeneration can lead to intervertebral disc disease. Mild degenerative changes in the structure of the canine intervertebral disc can be identified in magnetic resonance images, whereas these changes are not visible in computed tomographic images. Therefore, one aim of this study was to detect whether colour-coded computed tomography enhances the visibility of mild degenerative changes in the canine disc structure compared to non-contrast computed tomography. Furthermore, the study aimed to detect if intervertebral disc degeneration could be classified with a higher reliability in colour-coded images than in non-contrast images.

Results

Computed tomographic image studies of 144 canine intervertebral discs were coloured using three different lookup tables. Canine intervertebral disc degeneration was evaluated by three observers using a 5-grade classification system and compared to the evaluation of non-contrast CT and MRI images. A moderate to almost perfect intraobserver and a moderate to substantial interobserver agreement were found depending on the used colour code. On comparing non-contrast and colour-coded CT significant differences were found by one observer only. Significant differences in evaluation were found in grading intervertebral disc degeneration in MRI and colour-coded CT.

Conclusions

Intervertebral disc degeneration could not be classified with a higher reliability on colour-coded images compared to non-contrast images. Furthermore, colour-coded CT did not enhance the visibility of mild degenerative changes in disc structure compared to non-contrast CT.

However, the better intraobserver agreement and the subjective impression of the observers highlighted that the usage of colour encoded CT data sets with a wide range of tonal values of few primary and secondary colours may facilitate evaluation.

【 授权许可】

   
2015 Harder et al.

【 图 表 】

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【 参考文献 】

• [1]Bergknut N, Smolders LA, Grinwis GCM, Hagman R, Lagerstedt A, Hazewinkel HAW, Tryfonidou MA, Meij BP. Intervertebral disc degeneration in the dog. Part 1: Anatomy and physiology of the intervertebral disc and characteristics of intervertebral disc degeneration. Vet J. 2013; 195:282-291.
• [2]Jeffery ND, Levine JM, Olby NJ, Stein VM. Intervertebral Disk Degeneration in Dogs: Consequences, Diagnosis, Treatment, and Future Directions. J Vet Intern Med. 2013; 27:1318-1333.
• [3]Bergknut N, Auriemma E, Wijsman S, Voorhout G, Hagman R, Lagerstedt A, Hazewinkel HAW, Meij BP. Evaluation of intervertebral disk degeneration in chondrodystrophic and nonchondrodystrophic dogs by use of Pfirrmann grading of images obtained with low-field magnetic resonance imaging. Am J Vet Res. 2011; 72:893-898.
• [4]Pearce RH, Thompson JP, Bebault GM, Flak B. Magnetic resonance imaging reflects the chemical changes of aging degeneration in the human intervertebral disk. J Rheumatol Suppl. 1991; 27:42-43.
• [5]Benneker LM, Heini PF, Anderson SE, Alini M, Ito K. Correlation of radiographic and MRI parameters to morphological and biochemical assessment of intervertebral disc degeneration. Eur Spine J. 2005; 14:27-35.
• [6]Jones JC, Cartee RE, Bartels JE. Computed tomographic anatomy of the canine lumbosacral spine. Vet Radiol Ultrasound. 1995; 36:91-99.
• [7]Drees R, Dennison SE, Keuler NS, Schwarz T. Computed tomographic imaging protocol for the canine cervical and lumbar spne. Vet Radiol Ultrasound. 2009; 50:74-79.
• [8]Modic MT, Masaryk TJ, Ross JS, Carter JR. Imaging of degenerative disk disease. Radiology. 1988; 168:177-186.
• [9]Olby NJ, Müntana KR, Sharp NJH, Thrall DE. The computed tomographic appearance of acute thoracolumbar intervertebral disc herniation in dogs. Vet Radiol Ultrasound. 2000; 41:396-402.
• [10]Israel SK, Levine JM, Kerwin SC, Levine GJ, Fosgate GT. The relative sensitivity of computed tomography and myelography for identification of thoracolumbar intervertebral disk herniations in dogs. Vet Radiol Ultrasound. 2009; 50:247-252.
• [11]Harder L, Ludwig D, Galindo-Zamora V, Wefstaedt P, Nolte I. Classification of Canine Intervertebral Disc Degeneration in High-field Magnetic Resonance Imaging and Computed Tomography. Tierärztliche Praxis. 2014; 42:374-382.
• [12]Kalender W. Principles of Computed Tomography. In: Computed tomography: Fundamentals, system technology, image quality, applications. 2nd ed. Publicis Corporate Pub, Erlangen; 2005.
• [13]Zrenner E. Retinale Wahrnehmung. In: Physiologie. 6th ed. Hescheler J, Köhling R, Speckmann E, editors. Elsevier, Urban et Fischer, München; 2013: p.103-104.
• [14]Eysel U. Farbensehen. In: Physiologie. 6th ed. Klinke R, Pape H, Kurtz A, Silbernagl S, editors. Thieme, Stuttgart; 2010: p.736-738.
• [15]Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977; 33:159-174.
• [16]Kettler A, Wilke H. Review of existing grading systems for cervical or lumbar disc and facet joint degeneration. Eur Spine J. 2006; 15:705-718.
• [17]Pfirrmann CW, Metzdorf A, Zanetti M, Hodler J, Boos N. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine. 2001; 26:1873-1878.
• [18]Kovacs FM, Royuela A, Jensen TS, Estremera A, Amengual G, Muriel A, Galarraga I, Martínez C, Arana E, Sarasíbar H, Salgado RM, Abraira V, López O, Campillo C, del Real MTG, Zamora J. Agreement in the interpretation of magnetic resonance images of the lumbar spine. Acta Radiol. 2009; 50:497-506.