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- Author or Editor: Thomas W. Maddox x
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Abstract
OBJECTIVE To determine the mean diameter of the main portal vein (PV) in healthy dogs by use of CT angiography, identify any associations between PV diameter and certain dog characteristics, and validate a clinically valuable ratio for quantifying the size of the PV.
ANIMALS 100 dogs with no hepatic, cardiac, or vascular anomalies that underwent abdominal CT angiography.
PROCEDURES Diameters of the main PV, abdominal aorta (Ao), and caudal vena cava (CVC) were measured by 2 observers at a defined location on postcontrast CT angiographic images in axial, sagittal, and transverse planes. Dog characteristics were evaluated for associations with PV diameter, and a PV:Ao diameter ratio was calculated. Intraclass correlations were calculated to assess intra- and interobserver agreement in vessel diameter measurements.
RESULTS Mean diameter values were 7.9 mm (range, 4.1 to 14.8 mm) for the PV, 8.9 mm (range, 3.7 to 13.7 mm) for the Ao, and 11.4 mm (range, 4.4 to 22.5 mm) for the CVC. The PV:Ao diameter ratio was 0.91 mm. The PV diameter was significantly associated with dog body weight but not with dog age, sex, or neuter status. Intra- and interobserver reliabilities for measurements of all 3 vessels were considered excellent (intraclass correlation coefficients > 0.85).
CONCLUSIONS AND CLINICAL RELEVANCE Findings indicated that the PV:Ao diameter ratio was a repeatable measurement that may be useful for evaluating the size of the portal vasculature in dogs and possibly for distinguishing healthy PVs from abnormal PVs in dogs with hepatic vascular anomalies.
Abstract
OBJECTIVE
To compare the attenuation of the medial coronoid process (MCP) in dogs with and without arthroscopically confirmed evidence of medial coronoid disease (MCD).
ANIMALS
The database at our institution was searched for cases with thoracic limb lameness, diagnosed with MCD by arthroscopic examination that had CT as part of their investigation and compared with a control group of elbow joints from cadavers euthanized for reasons unrelated to MCD. A total of 84 elbow joints were included that met these criteria.
PROCEDURES
Following CT, a standardized measurement of the MCP was obtained from apex to base and the mean attenuation, SD, and total area were recorded. A comparative measurement was obtained from the proximal radial cortex at the level of the nutrient foramen. Elbow joint arthroscopy was carried out using standard portals, and the modified Outerbridge score was (MOS) used to score elbow joint cartilage. Descriptive and inferential statistics were carried out using MLwiN and R.
RESULTS
Attenuation of the MCP was reduced in dogs with MCD compared with those with no MCD (P < .002). No significant differences were observed in the attenuation between categories of severity (MOS). There was good inter- and intraobserver agreement between measurements (intraclass correlation coefficient = 0.89 and 0.95, respectively).
CLINICAL RELEVANCE
MCP attenuation is reduced in dogs with MCD compared with dogs with no evidence of MCD. This finding may be a useful tool for early detection of MCD, but there is no relationship with arthroscopic lesion severity.
Abstract
OBJECTIVE
To assess the prevalence of bronchial wall thickening (BWT) and collapse in brachycephalic dogs with and without brachycephalic obstructive airway syndrome (BOAS) and in nonbrachycephalic dogs.
ANIMALS
85 dogs with no history of lower respiratory tract disease that underwent CT of the thorax.
PROCEDURES
Electronical medical records for March 2011 through August 2019 were reviewed to identify brachycephalic dogs with BOAS (BOAS group) and brachycephalic dogs without BOAS (BDWB group) that did not have any evidence of lower respiratory tract disease and had undergone thoracic CT. A population of nonbrachycephalic dogs of similar weight (control dogs) was also retrospectively recruited.
RESULTS
BWT was identified in 28 of 30 (93.3%; 95% CI, 80.3% to 98.6%) dogs in the BOAS group, 15 of 26 (57.7%; 95% CI, 38.7% to 75.0%) dogs in the BDWB group, and 10 of 28 (35.7%; 95% CI, 20.1% to 54.2%) control dogs. On multivariable analysis, only brachycephalic conformation (P < 0.01) and body weight (P = 0.02) were significantly associated with the presence of BWT. Bronchial collapse was identified in 17 of 30 (56.7%; 95% CI, 39.0% to 73.1%) dogs in the BOAS group, 17 of 26 (65.4%; 95% CI, 46.3% to 81.3%) dogs in the BDWB group, and 3 of 28 (10.7%; 95% CI, 3.1% to 25.9%) control dogs. On multivariable analysis, only brachycephalic conformation was significantly (P < 0.01) associated with the presence of bronchial collapse.
CLINICAL RELEVANCE
A relationship between brachycephalic conformation and body weight with BWT was established, with heavier dogs having thicker bronchial walls. However, further studies are required to investigate the cause. Bronchial collapse was also more common in dogs with brachycephalic conformation, which is in agreement with the previously published literature.
Abstract
OBJECTIVE To determine the ultrasonographic appearance of the major duodenal papilla (MDP) in dogs without evidence of hepatobiliary, pancreatic, or gastrointestinal tract disease.
ANIMALS 40 adult client-owned dogs examined because of conditions that did not include hepatobiliary, pancreatic, or gastrointestinal tract disease.
PROCEDURES Ultrasonographic examination of the MDP was performed. Each MDP was measured in 3 planes. Intraobserver reliability of measurements was determined, and associations between MDP dimensions and characteristics of the dogs were investigated. Histologic examination of longitudinal sections of the MDP was performed for 1 dog to compare the ultrasonographic and histologic appearance.
RESULTS The MDP appeared as a layered structure with a hyperechoic outer layer, hypoechoic middle layer, and hyperechoic inner layer that corresponded to the duodenal serosa, duodenal muscularis, and duodenal submucosa, respectively. Layers visible during ultrasonographic examinations were consistent with layers identified histologically. Intraobserver reliability was substantial for each plane of measurement. Mean ± SD length, width, and height of the MDP were 15.2 ± 3.5 mm, 6.3 ± 1.6 mm, and 4.3 ± 1.0 mm, respectively. An increase in body weight of dogs was significantly associated with increased values for all measurements.
CONCLUSIONS AND CLINICAL RELEVANCE The ultrasonographic appearance and approximate dimensions of the MDP of dogs without evidence of hepatobiliary, pancreatic, or gastrointestinal tract disease were determined. Additional studies are needed to evaluate possible ultrasonographic lesions of the MDP in dogs with hepatobiliary, pancreatic, or intestinal diseases and to investigate clinical implications of these lesions with regard to diagnosis and prognosis.
Abstract
OBJECTIVE
Treatment of orofacial tumors in dogs is associated with high morbidity and reliable prognostic factors are lacking. Dynamic contrast-enhanced computed tomography (DCECT) can be used to assess tumor perfusion. The objectives of this study were to describe the perfusion parameters of different types of orofacial tumors and to describe the changes in perfusion parameters during radiotherapy (RT) in a subset of them.
ANIMALS
11 dogs with orofacial tumors prospectively recruited.
CLINICAL PRESENTATION AND PROCEDURES
All dogs had baseline DCECT to assess blood volume (BV), blood flow (BF), and transit time (TT). Five dogs had repeat DCECT during megavoltage RT.
RESULTS
5 squamous cell carcinomas, 3 sarcomas, 1 melanoma, 1 histiocytic sarcoma, and 1 acanthomatous ameloblastoma were included. Blood volume and BF were higher in squamous cell carcinomas than in sarcomas, although no statistical analysis was performed. At repeat DCECT, 4 dogs showed a reduction in the size of their tumor during RT. Among these dogs, 3 showed an increase in BV and BF and 1 a decrease in these parameters between the baseline and the follow-up DCECT. The only dog whose tumor increased in size between the first and the second DCECT showed a decrease in BV and BF.
CLINICAL RELEVANCE
Perfusion parameters derived from DCECT were described in a series of dogs with various types of orofacial tumors. The results suggest that epithelial tumors could have higher BV and BF than mesenchymal tumors, although larger sample sizes are needed to support these preliminary findings.
Abstract
OBJECTIVE To characterize CT findings in dogs with a presumptive diagnosis of chronic bronchitis, estimate the accuracy of thoracic CT for the diagnosis of chronic bronchitis in dogs, and determine interobserver agreement for this method.
DESIGN Retrospective case-control and cross-sectional study.
ANIMALS 26 dogs with confirmed chronic bronchitis and 20 control dogs with unremarkable results of thoracic CT and no recorded history of cough.
PROCEDURES Thoracic CT images of all dogs were interpreted for signs of chronic bronchitis by 2 observers who used specific criteria; observers also used the images to compute the bronchial wall thickness-to-pulmonary artery diameter (BWPA) ratio of the cranial lung lobes. Interobserver agreement was assessed for both diagnostic approaches. Performance of thoracic CT and the BWPA ratio specifically in the diagnosis of chronic bronchitis were evaluated, with the final diagnosis made by the attending internist as the reference standard. Associations between independent variables and the BWPA ratio for all dogs were assessed by linear regression.
RESULTS Accuracy of thoracic CT examination for the diagnosis of chronic bronchitis was 57%, sensitivity was 46%, and specificity was 90%. Interobserver agreement was moderate (κ = 0.50). The BWPA ratio had poor accuracy for discriminating dogs with chronic bronchitis from control dogs. Linear regression revealed that as dog body weight increased, BWPA ratios for the left and right cranial lung lobes decreased slightly but significantly.
CONCLUSIONS AND CLINICAL RELEVANCE These results suggested that thoracic CT and the associated BWPA ratio have limited value in the diagnosis of chronic bronchitis in dogs.
