Prevalence of canine renal crest hyperattenuation in precontrast computed tomography.

Normal canine kidneys are relatively homogeneous soft tissue attenuating structures on nonenhanced CT images. However, visible differences in attenuation between the renal crest and medulla are occasionally observed. This finding and its potential clinical implications have not been previously investigated. This study aimed to estimate the prevalence of renal crest hyperattenuation (RCH) and investigate possible associations with signalment and laboratory parameters. Abdominal CT studies from 100 dogs, with biochemistry and urinalysis data obtained within 48 h before the CT acquisition, were categorized by two radiologists into those with and without visible RCH. The attenuation in Hounsfield units (HU) of the renal crest and renal medulla were measured. Signalment, biochemical, and urinalysis data were analyzed for associations with RCH. Correlation coefficients were calculated for measured HU and associated continuous parameters. Prevalence of RCH was 42.42% (42/99 dogs, 95% CI, 33-52%). Urinary specific gravity (USG) was significantly different between dogs with and without RCH (P = .034). Weak positive correlations were identified between left and right renal crest attenuation and USG (r = 0.233 and 0.253, respectively; P = .05). Renal crest hyperattenuation is a common finding in dogs undergoing abdominal CT. Although the correlation between the USG and renal crest HU is weak, the dogs with RCH have significantly higher USG. Renal crest hyperattenuation might, therefore, not be associated with renal insufficiency. No other specific associations of RCH were identified with parameters typically altered in a variety of diseases. Further investigation may be warranted for its relevance to specific diseases or if it indeed represents a physiological variant.

Accuracy of radiographic diagnosis of pneumoperitoneum secondary to gastrointestinal perforation in dogs and cats.

BACKGROUND: Radiography is commonly included in the diagnostic investigation of animals with suspected gastrointestinal perforation and resultant pneumoperitoneum. This study aimed to (1) identify the accuracy of radiographic diagnosis of pneumoperitoneum and (2) determine if observer experience affected accuracy. METHODS: This was a retrospective case-controlled study evaluating abdominal radiographs of dogs and cats with surgical confirmation of gastrointestinal perforation or peritonitis without pneumoperitoneum. Radiographs were reviewed by a radiologist, an imaging resident, a general practitioner and a veterinary student. RESULTS: Radiographs from 60 dogs and eight cats were evaluated; 34 animals had confirmed perforation. Accuracy was fair to excellent for all observers: student 61.8%, general practitioner 70.6%, resident 85.3% and radiologist 83.8%. There was no significant difference in sensitivity between observers (all 70.6%-85.3%); however, there was a significant difference in specificity between both the resident (91.2%) and radiologist (91.2%) compared to the student (52.9%) (p < 0.001) and the general practitioner (55.9%) (p = 0.002). Overall, there was slight to substantial agreement between observers (κ = 0.28-0.73), with the highest being between the radiologist and resident. CONCLUSION: Abdominal radiography, when interpreted by veterinarians with differing experience, has variable accuracy for diagnosis of pneumoperitoneum for animals in this study. Further studies are needed to determine if these results are applicable for other populations of animals with pneumoperitoneum.

Prevalence of bronchial wall thickening and collapse in brachycephalic dogs with and without brachycephalic obstructive airway syndrome and in nonbrachycephalic dogs.

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.

Cranial solitary osseous plasmacytoma and subjacent amyloid deposition in a dog.

Solitary osseous plasmacytomas affecting the vertebrae, the zygomatic arch, and ribs occur in dogs. In this report, we describe clinical and imaging features of a solitary osseous plasmacytoma affecting the skull with deposition of amyloid forming a mass-like lesion. To the authors' knowledge, no similar cases have been reported before.

Mediastinal lymphoma in dogs is homogeneous compared to thymic epithelial neoplasia and is more likely to envelop the cranial vena cava in CT images.

In order to identify CT signs that could be used to distinguish cranial mediastinal lymphoma and thymic epithelial neoplasia, a retrospective case-control study was done. Associations between CT signs and diagnosis were tested using binary logistic regression and results expressed as odds ratio and 95% confidence interval. Sixty-two dogs that had thoracic CT and confirmed diagnosis of lymphoma (n = 33) or thymic neoplasia (n = 29) were sampled. Thymic neoplasms included 24 thymomas and five thymic carcinomas. Dogs with thymic epithelial neoplasia were significantly older than dogs with lymphoma (median age 8.6 years versus 6.0 years, P = .007), but there were no significant differences in prevalence of clinical signs. Diagnosis of thymic epithelial neoplasia was associated with heterogeneous attenuation in pre- (odds ratio 23.3, 95% confidence interval, 4.5-121.1) and post-contrast (odds ratio 30.7, 95% confidence interval, 3.6-265.0) images. Conversely, envelopment of the cranial vena cava by the mass was less likely with thymic epithelial neoplasia than lymphoma (odds ratio 0.07, 95% confidence interval, 0.007-0.66). Greater standard deviation of Hounsfield unit values in post-contrast images was associated with thymic epithelial neoplasia (P = .005). Based on ROC analysis, SD > 17HU of the mass in post-contrast images had a sensitivity of 72% and specificity of 79% for thymic epithelial neoplasia. There were no significant differences in morphology, prevalence of calcification, mediastinal lymphadenopathy, cranial vena cava invasion, collateral vessels, or pleural fluid associated with these tumors. Thymic epithelial neoplasms tended to occur in older dogs and were heterogeneous in CT images, whereas mediastinal lymphoma was more homogeneous and more likely to envelop the cranial vena cava.

Postnatal maturation of tendon, cruciate ligament, meniscus and articular cartilage: a histological study in sheep.

Orthopaedic basic science data on immature skeletons are rare in the literature. Since the number of knee injuries in young humans is steadily increasing, studies on immature animals such as sheep, which can be used as model systems are becoming more and more important. However, no baseline data are available on physiologic and morphologic changes during growth in the relevant tissues. In the present study, histomorphometric changes in the tendon of the musculus flexor digitalis superficialis, the cranial cruciate ligament, the medial meniscus and the articular cartilage of the medial femoral condyle were identified in sheep between the ages of 1 and 40 weeks postnatally. Profound changes in tissue composition during growth could be observed. A high cellularity in the early postnatal period decreases to a constant lower level after 18 weeks. Similar changes during postnatal growth could be observed for blood vessel density. Also, staining of alpha-smooth muscle actin (SMA) and vascular endothelial growth factor (VEGF) steadily decreased. In contrast, the number of components of extracellular matrix steadily increased in all tissues. The age of 18 weeks seems to be a threshold after which the tissue composition of the observed structures remains constant in this species.