Murino, Carla (2017) Esame TC in corso di Displasia del gomito del cane. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Lingua: Italiano
Title: Esame TC in corso di Displasia del gomito del cane
Creators:
CreatorsEmail
Murino, Carlacarla.murino@unina.it
Date: 9 April 2017
Number of Pages: 144
Institution: Università degli Studi di Napoli Federico II
Department: Medicina Veterinaria e Produzioni Animali
Dottorato: Scienze veterinarie
Ciclo di dottorato: 29
Coordinatore del Corso di dottorato:
nomeemail
Cringoli, GiuseppeUNSPECIFIED
Tutor:
nomeemail
Meomartino, LeonardoUNSPECIFIED
Date: 9 April 2017
Number of Pages: 144
Uncontrolled Keywords: CT, canine elbow dysplasia, dog
Settori scientifico-disciplinari del MIUR: Area 07 - Scienze agrarie e veterinarie > VET/09 - Clinica chirurgica veterinaria
Date Deposited: 08 May 2017 06:53
Last Modified: 07 Mar 2018 13:06
URI: http://www.fedoa.unina.it/id/eprint/11672

Abstract

Introduction: Canine Elbow dysplasia (CED) is one of the most common cause of artropathy in large and giant size dogs. At least 4 forms of CED are described: Ununited Anconeal Process (UAP); Osteocondritis dissecans (OCD) of the humeral condyle; fragmented medial coronoid process (FMCP); elbow incongruity (EI) for short radius, short ulna or underdeveloped ulnar troclear notch. CED is often assessed using computed tomography (CT), particularly in case of inconsistent or not definitive radiographical diagnosis. However, until now there is not any standardized protocol for the elbow CT. A number of procedures have been proposed, but they all require a great stressful positioning of the cervical spine since the head is pulled laterally or caudally, in order to avoid beam-hardening and streak artifacts. The aim of this study was to describe CT findings in dogs with CED and to propose a new, non-stressful procedure for CT of the canine elbow using a lateral recumbent position and a specifically designed positioning device. Material and Methods: The study was performed at the Interdepartmental Radiology Veterinary Centre of the University Federico II of Naples and it was developed in two steps: first, a retrospective analysis of CT exams of the elbow performed on dogs affected by suspect CED, from January 2005 to December 2011; and second, a prospective analysis of CT exams performed with the new proposed procedure, from January 2012 to December 2016. All of the CT exams were performed on dogs under general anesthesia. In all subjects, both elbows were studied at the same time. In the new procedure, the dogs were placed on the CT bed ever in the lateral recumbent position with the forelimbs cranially pulled and, in order to obtain the best elbow alignment and to remove the air gap between the neck and the forelimbs, a purpose-handmade positioning device, shaped from polyurethane foam, was used. For comparative purposes, in two dogs, the elbow CT was also performed using a previously described procedure, i.e. in sternal recumbent position with the forelimbs parallel one to each other and cranially extended and the head and neck laterally and caudally pulled. All of the CT exams were obtained using 1 mm thick contiguous axial slices at 120 kV and 200–260 mAs, together with a bone convolution filter, and evaluated on a workstation equipped with a DICOM software, using a bone window [window level (WL) 500, window width (WW) 3000]. In order to improve the evaluation, multiplanar reconstruction (MPR) and three dimensional volume rendering (3D-VR) images were obtained too. For each joint, the presence or absence of a primary lesion (FCP, OCD, UAP, EI), possibly associated to a “Kissing Lesions” (KL), was assessed. Furthermore, each joint was analytically assessed for the visualization of relevant anatomical landmarks such as the medial coronoid process, humero-radio-ulnar joint space, anconeal process, humeral condyle, subchondral bone, proximal radial and ulnar relationship. In addition, the presence of sclerosis, periarticular osteophites, subchondral cyst-like lesions, deformed, fissured or fragmented medial coronoid process, incongruence from short radius, short ulna or underdeveloped ulnar troclear notch were evaluated too. CT quality was assessed measuring the image noise represented by the standard deviation of Hounsfiel unit (HU) in a region of interes (ROI) manually traced around the bones of the elbows at three omologous level. Data obtained were compared using the Wilcoxon rank test for paired data, with a significance level of p<0.05. Results: 61 dogs, 45 males and 16 females, mean age of 11.7 months, for a total of 122 elbows were collected. Breed distribution was: Labrador retriever (24), German shepherd (11), rottweiler (5), golden retriever (4), dogue de Bordeaux (3), Bernese mountain dog (2), chow chow (2), mix breed (2), Alaskan Malamute (1), American Staffordshire (1), Belgian Shepherd (1), border collie (1), Bloodhound (1), cane corso (1), pitbull Terrier (1), and terranova (1). In three dogs, elbows were bilaterally normal. Fifty-eight dogs were affected by dysplasia (43 dogs bilaterally and 15 monolaterally affected). There were 88 EI, 70 FMCP, 10 OCD and 3 UAP. All of the images obtained using the new procedure were of diagnostic use. There were not any significant differences in CT quality between the new procedure and the previously described one. The purpose-handmade device demonstrated to help the positioning and to avoid the appearance of streaks or beam hardening artifacts. Discussion and Conclusion: Labrador retriever and German shepherd dogs confirmed to be particularly prone to CED. There was a high prevalence of male dogs, as reported in other studies. Our results confirmed the high sensitivity and accuracy of CT in diagnosing CED, particularly in case of EI and FMCP. The EI represents the most prevalent lesion found in our sample. Actually, this finding has to be related to the higher sensitivity of the CT examination in diagnosing EI even when small gaps of incongruence (<2mm) are present. The FMCP represents the second most frequent lesion in our sample This particular distribution can be referred both to the higher prevalence of this lesion among those responsible of CED or to the fact that, usually, CT is performed when radiographs were questionable for the presence of FMCP. This explanation can justify also the small number of OCD and UAP in our sample as well as in others, since those two lesions are easily diagnosed with radiography. In spite of the high sensitivity and specificity of elbow CT, to date there is not any standardized protocol, universally accepted. A number of procedures have been described, all of which designed to avoid streak and beam-hardening artifacts by entering only the elbows in the gantry but, in order to obtain this, the neck is subject to a stressful positioning. Considering that most of the canine breeds predisposed to develop CED are, at the same time, at high risk for caudal cervical spondylopathy (Wobbler syndrome), in our opinion, all the positionings used in the previously described methods are potentially dangerous. Our experience shows that the lateral recumbency with both forelimbs pulled cranially, obtained with the help of the positioning device, represents a simple and safe positioning and that the quality of the images is comparable and without streak or beam hardening artifats. The positioning device, developed during the study, demonstrated its usefulness so that, recently, we started to create a prototype computer made. In conclusion, the CT procedure described here offers several advantages over existing procedures: non-stressful positioning; simple and quick, even in giant dogs, owing to the special positioning device; high quality images with low noise; easy image assessing thanks to simultaneous visualization of both elbows.

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