Rapid brain MRI protocols result in comparable differential diagnoses versus a full brain protocol in most canine and feline cases.

Evaluation of brain disease in veterinary patients uses a wide variety of MRI sequences. A shortened protocol that maintains consistency of interpretation would reduce radiologist reporting time, patient anesthetic time, and client cost. The aims of this retrospective, methods comparison, observer agreement study were to evaluate whether abbreviated MRI protocols alter differential diagnoses and recommendations compared to our institution's standard protocol; evaluate interobserver agreement on standard brain MRIs; and assess whether differential diagnoses change after postcontrast images. Normal and pathologic canine and feline brain MRIs were retrieved from hospital archives. Three protocols were created from each: a 5-sequence noncontrast enhanced Fast Brain Protocol 1 (FBP1); a 6-sequence contrast-enhanced Fast Brain Protocol 2 (FBP2); and an 11-sequence standard brain protocol (SBP). Three blinded veterinary radiologists interpreted FBP images for 98 cases (1 reader/case) and SBP images for 20 cases (3 readers/case). A fourth observer compared these interpretations to the original MRI reports (OMR). Overall agreement between FBPs and OMR was good (k = 0.75) and comparable to interobserver agreement for multiple reviews of SBP cases. Postcontrast images substantially altered conclusions in 17/97 cases (17.5%), as well as improved interobserver agreement compared to noncontrast studies. The conclusions reached with shortened brain protocols were comparable to those of a full brain study. The findings supported the use of a 6-sequence brain MRI protocol (sagittal T2-weighted [T2w] TSE; transverse T2w turbo spin echo fluid-attenuated inversion recovery, T2*-weighted gradient recalled echo, T1-weighted spin echo, and diffusion weighted imaging/apparent diffusion coefficient; and postcontrast transverse T1-weighted spin echo) for dogs and cats with suspected intracranial disease.

Dogs and cats with presumed or confirmed intracranial abscessation have low apparent diffusion coefficient values.

Intracranial abscessation is a life-threatening condition in dogs and cats, and rapid diagnosis is important for prognosis and treatment planning. The aims of this retrospective, single-center, case series study were to describe clinical and MRI diffusion-weighted imaging characteristics in three dogs and three cats with presumed or confirmed intracranial abscessation. All lesions appeared hyperintense on b1000 trace diffusion-weighted images, hypointense on apparent diffusion coefficient (ADC) map, with mean ADC values ranging from 0.37 to 1.24 × 10-3  mm2 /s. The majority (5/6) of the obtained mean ADC values were low (<1.10 × 10-3  mm2 /s), as previously reported in the human literature.

Evidence-Based Approach to Switching to a Pass-Fail System for Clinical Year Veterinary Student Grading.

Veterinary schools have traditionally used letter grading systems to assess the performance of students on clinical rotations, but pass-fail grading may enhance the learning environment and student well-being. When a decision to switch grading systems is discussed, concerns are often raised about the effect of removing clinical year grades from final grade point average (GPA) calculations. In order to inform the decision making at our institution, retrospective analysis of the effects of clinical year grades on GPA was performed. The specific hypothesis tested was that clinical year GPA would not have a significant effect on cumulative GPA, as defined by a decrease or increase of 0.10 points on average. When data from two classes were examined, median (range) difference final GPA (0-4 scale) compared to GPA at the end of the pre-clinical curriculum (referred to as delta GPA) was 0.02 (-0.19 to 0.18) for the graduating class of 2016 after removal of two outliers and 0.03 (-0.10 to 0.18) for the class of 2017. Correlations between preclinical GPA and delta GPA (were -0.83 (p < .001) for both classes. The hypothesis was supported, leading to the conclusion that the overall effect of clinical letter grades on final GPA was close to zero when whole classes were considered, and delta GPA ranged between -0.2 and 0.2 for all except two students. Data from this study were distributed prior to conducting a faculty vote to switch grading systems, and the motion was supported.

Atypical and malignant canine intracranial meningiomas may have lower apparent diffusion coefficient values than benign tumors.

Canine intracranial meningiomas can be graded based on histological classification as benign (grade I), atypical (grade II), and anaplastic or malignant (grade III). In people, grade II/III meningiomas behave more aggressively, have a higher potential for recurrence after surgical resection, and have lower apparent diffusion coefficient (ADC) values with diffusion weighted imaging (DWI). In this retrospective analytical cross-sectional study, 42 dogs had ADC values quantified in an attempt to differentiate tumor histologic grade. Our hypothesis was that ADC values would be significantly lower in grade II and III versus grade I meningiomas in dogs. On each ADC image, a polygonal region of interest (ROI) was hand-drawn along the lesion's periphery, excluding fluid-filled and hemorrhagic regions. Mean ADC value (ADCmean ) and minimum ADC value (ADCmin ) were calculated. Additionally, two smaller, ovoid ROI were drawn within the lesion with mean ADC calculated (ADCmean sR and ADCmin sR ). Normalized ADC values using white matter were also calculated (ADCn and ADCn sR ). Grades of each tumor were assigned based on histopathology review. Association between ADC parameters and histological grade was tested by means of two-sample t-tests. There were 14 grade I (33.3%), 25 grade II (59.5%), and three grade III (7.2%) meningiomas. ADCmean sR and ADCmin sR were significantly lower when comparing grade II/III to grade I (P < .05). Grade II tumors had significantly lower ADCmean , ADCmean sR , ADCmin sR , ADCn , and ADCn sR than grade I meningiomas. This preliminary study supports the potential of ADC values to help predict the histological grade of intracranial meningiomas in dogs.

Early and Increased Training in Veterinary Radiology Increases Student Interest in the Specialty But May Provide Little Short-Term Gain in Radiology Knowledge.

There is a lack of consensus among educators regarding the ideal structure of radiology training in veterinary medicine. Research in the medical field suggests that early integration has positive short- and long-term impacts on student interest in radiology. This study evaluated the effect of a new radiology course in the first year of the veterinary curriculum. Authors hypothesized that students taught radiology in years 1 and 2 would have greater interest in and appreciation for the specialty of radiology and would perform better on tests of basic knowledge of medical imaging principles, entry-level image interpretation, and anatomy identification than students who were not taught until year 2. An online questionnaire was administered to different classes of students after completion of their radiology courses. Students with early and increased radiology training were significantly more likely to respond that radiology was more interesting than other veterinary specialties. Unexpectedly, students with early and increased training performed significantly better than students with less and later training on only one out of nine content knowledge questions, though they did perform significantly better on additional knowledge questions compared to students with only early exposure. This suggests early and increased training in radiology may increase student interest in and appreciation for the specialty, but may not lead to increased short-term knowledge retention compared to a traditional curriculum format.

Comparison of a computed tomographic pulmonary trunk to aorta diameter ratio with echocardiographic indices of pulmonary hypertension in dogs.

There are limited criteria for the detection of pulmonary hypertension in dogs undergoing computed tomography (CT) for pulmonary disease. This retrospective analytical exploratory study compared a CT pulmonary trunk to aorta ratio with echocardiographic estimates of pulmonary hypertension. Dogs having both a contrast thoracic CT and echocardiogram were selected and maximal pulmonary trunk and descending aorta diameters were measured by two observers on a single transverse CT image. Computed tomographic diameter ratios were compared with the echocardiographic parameters of tricuspid regurgitation gradient, right ventricular acceleration time-to-ejection time ratio, pulmonary insufficiency gradient, and pulmonary artery to aorta diameter. A total of 78 dogs were sampled, with 44 dogs having one or more finding suggestive of pulmonary hypertension. A moderate positive correlation was shown between tricuspid regurgitation gradient and CT pulmonary trunk to aorta ratio (r = 0.61, P-value < 0.0001). Mean CT pulmonary trunk to aorta ratio of dogs with moderate (P = 0.0132) and severe (P < 0.0003) pulmonary hypertension were significantly higher than normal dogs. There was no significant difference in mean CT pulmonary trunk to aorta ratio between normal and mild pulmonary hypertension dogs (P = 0.4244). The intraclass correlation coefficient (0.72) showed good reproducibility of the ratio. Findings indicated that CT pulmonary trunk to aorta ratio is a reproducible and potentially useful method to predict moderate and severe pulmonary hypertension in dogs, but not mild pulmonary hypertension. In dogs undergoing thoracic CT for pulmonary disease, an increased ratio should prompt follow up echocardiography.

Diagnostic sensitivity of bone scintigraphy for equine stifle disorders.

Disorders of the stifle are a common cause of lameness in horses yet the accuracy of scintigraphy for diagnosis of stifle conditions is controversial. The aim of retrospective cross-sectional study was to determine the diagnostic sensitivity (Se) of bone scintigraphy in detecting stifle disease and to determine if two orthogonal scintigraphic images improve diagnostic Se. Horses that underwent scintigraphic examination during a two-year period were included. Horses were divided into two groups: group 1 (N = 23) had lameness that was localized to the stifle by intra-articular analgesia and group 2 (N = 182) had lameness that was localized to a different location. Scintigraphic studies (one image or two images) were independently and retrospectively analyzed by two radiologists (R1 and R2). Sensitivity, specificity (Sp) and predictive values (PV), and were calculated for each type of study (one image or two images) and for each radiologist (R1 or R2). The Se to detect stifle disorders varied between radiologists (29.2% and 20.8%). The Sp was 84.5% and 88.3%. When two images were evaluated a decrease in the positive PV for both readers occurred. The Cohen kappa coefficient (κ) between readers was poor when one image (0.084) or two images (0.117) were evaluated. Findings from this study indicated that bone-phase nuclear scintigraphy is reasonably specific but highly insensitive for detecting lameness originating from the stifle in a diverse population of both normal and affected horses. The addition of a caudal scintigraphic image acquisition did not improve diagnostic sensitivity.

Accuracy of a computed tomography bronchial wall thickness to pulmonary artery diameter ratio for assessing bronchial wall thickening in dogs.

Computed tomography is increasingly being used in veterinary medicine to evaluate animals with pulmonary signs such as coughing, tachypnea, and exercise intolerance, however, a quantitative measure of bronchial wall thickening has yet to be validated in veterinary medicine. Canine chronic bronchitis is a disease that is characterized histologically by thickening of the bronchial walls. Thoracic CT images of 16 dogs with chronic bronchitis and 72 dogs presenting for conditions unrelated to cough were evaluated. A ratio comparing the bronchial wall thickness to the adjacent pulmonary artery diameter was obtained in the right and left cranial and caudal lung lobes. There was no significant difference in dogs with chronic bronchitis or unaffected dogs between the left and right hemithorax, patient weight, patient age, image slice thickness, or CT machine used. Dogs with chronic bronchitis were found to have a significantly greater ratio than unaffected dogs (P < 0.001). The ratios in the cranial lung lobes were found to be significantly greater than the caudal lung lobes in both chronic bronchitis and unaffected dogs (P < 0.001). A receiver operating characteristic curve of the ratios in the cranial lung lobes had an area under the curve of 0.912, indicating high accuracy in predicting for bronchial wall thickening. A ratio of ≥ 0.6 in the cranial lung lobes was found to have a sensitivity of 77% and specificity of 100% in predicting for the presence of chronic bronchitis, and we propose using this cut-off as supportive of bronchial wall thickening on CT.

ULTRASONOGRAPHIC FEATURES OF CANINE GASTROINTESTINAL STROMAL TUMORS COMPARED TO OTHER GASTROINTESTINAL SPINDLE CELL TUMORS.

Canine gastrointestinal stromal tumors (GISTs) are a recent subtype of gastrointestinal spindle cell tumor recognized with the increasing use of immunohistochemistry. To our knowledge, no imaging features have been described in immunostochemically confirmed canine GISTs. The objective of this retrospective, cross-sectional study was to describe ultrasonographic features of canine GISTs compared with other spindle cell tumors. Thirty-seven dogs with an ultrasonographically visible gastrointestinal mass and a histopathologic diagnosis of spindle cell neoplasia were examined. Immunohistochemistry staining was performed for retrieved tissue samples to further differentiate the tumor type and each sample was interpreted by a single veterinary pathologist. Ultrasonographic features recorded examined included mass echogenicity, homogeneity, presence of cavitation, layer of origin, bowel wall symmetry, and loss of wall layering, location, size, vascularity, and evidence of perforation or ulceration. Tumor types included 19 GISTs, eight leiomyosarcomas, six leiomyomas, and four nonspecified sarcomas. Gastrointestinal stromal tumors were significantly more likely to be associated (P < 0.03) with abdominal effusion than other tumor types. There was overlap between the anatomical locations of all tumors types with the exception of the cecum where all eight tumors identified were GISTs. Besides location, there were no unique ultrasound features of GISTs that would allow distinction from other gastrointestinal spindle cell tumors. Similar to previous studies, GISTs appeared to be the most common spindle cell tumor associated with the cecum in our sample of dogs. The high frequency of abdominal effusion with GIST's was of unknown etiology could possibly have been due to septic peritonitis.

Abdominal aortic aneurysm associated with systemic fungal infection in a German shepherd dog.

A 2 yr old spayed female German shepherd presented with a chief complaint of acute onset paraparesis and weight loss. At presentation, the dog was pyrexic, nonambulatory, and had generalized muscle wasting. Neurolocalization was consistent with a thoracolumbar spinal cord lesion. An abdominal ultrasound was performed and revealed a focal dilation (4 cm) of the terminal aorta with evidence of blood stasis consistent with an aortic aneurysm. The dog was euthanized shortly after admission to the hospital and a post mortem examination was performed. Fungal organisms were identified in the aortic aneurysm as well as from the thoracic vertebrae, mesenteric lymph nodes, axillary lymph nodes, spleen, kidneys, liver, lungs, and heart. Although the morphology was consistent with Candida spp., immunohistochemistry and PCR could not definitively identify the causative organism. Mycotic aortic aneurysms are a rare finding in humans and have not been previously reported in the dog. To the authors' knowledge, this is the first known report of an aortic aneurysm associated with systemic fungal infection in a dog.

Comparison of computed tomographic attenuation values for epaxial muscles in old and young dogs.

OBJECTIVE To determine whether the degree of CT attenuation of muscle would differ between healthy old and young dogs. ANIMALS 10 healthy old (> 8 years old) and 9 healthy young (1 to 5 years old) Labrador Retrievers with a body condition score of 5 or 6 on a 9-point scale. PROCEDURES CT was performed with the dogs mildly sedated. A freehand closed polygon tool was used to define the outer margin of the left epaxial muscles on each transverse image obtained from the cranial to caudal endplates of T13. The CT attenuation values from every voxel from within these regions of interest were exported from DICOM software as a single dataset in an extensible markup language file. From these data, mean CT attenuation values were calculated for each dog and these mean values were compared between age groups. RESULTS Mean CT attenuation values for the epaxial muscles were significantly lower in old dogs than in young dogs. A significant negative correlation (r = -0.74) was identified between mean CT attenuation values and dog age. CONCLUSIONS AND CLINICAL RELEVANCE In addition to loss of skeletal muscle mass, low muscle CT attenuation values suggested that the old dogs in this study also had greater muscle fat content than did young dogs. Additional studies are warranted to evaluate qualitative and quantitative muscle changes in old dogs.

Compartment syndrome of the muscles of mastication in a working dog following a traumatic training incident.

OBJECTIVE: To describe acute compartment syndrome (CS) of the muscles of mastication in a working dog associated with a traumatic training event. CASE SUMMARY: A 2.5-year-old male Belgian Malinois was evaluated for acute blindness, severe diffuse swelling of the head, and inability to close the jaw following a traumatic incident during a bite training drill. During the exercise, the maxillary canine teeth were locked on a bite sleeve. Magnetic resonance imaging of the head and ocular system identified diffuse muscle swelling and hyperintensity, most severe in the muscles of mastication. Ocular abnormalities were not identified. Rhabdomyolysis, CS, and indirect optic nerve injury were supported by measurement of increased intramuscular pressure. Bilateral decompressive fasciotomies over the masseter and temporalis muscles resulted in immediate and marked resolution of the swelling and jaw movement. Blindness, however, did not resolve. NEW OR UNIQUE INFORMATION PROVIDED: CS involving the muscles of mastication may occur as a complication of bite training and may result in irreversible and even life-threatening complications. Emergent decompressive fasciotomy is indicated to reverse swelling; however, visual deficits may not resolve.

Ultrasonographic evaluation of the canine urinary bladder following cystotomy for treatment of urolithiasis.

OBJECTIVE To describe the ultrasonographic appearance of the urinary bladder incision site in dogs that underwent cystotomy for treatment of urolithiasis. DESIGN Prospective, longitudinal study. ANIMALS 18 client-owned dogs. PROCEDURES Dogs underwent urinary bladder ultrasonography at baseline (≤ 1 day before surgery) and at 1 day and approximately 2, 6, and 12 weeks after cystotomy for urocystolith removal. A baseline ratio between ventral (cystotomy site) and corresponding dorsal midline wall thickness was calculated and used to account for measurement variations attributable to bladder distension at subsequent visits. Patient signalment, weight, medications administered, urocystolith composition, and culture results were recorded. Clinical signs, reoccurrence of hyperechoic foci, and suture visualization were recorded at follow-up examinations. Variables were evaluated for association with cystotomy site thickening and resolution of thickening. RESULTS Median wall thickness at the ventral aspect of the bladder was significantly greater than that of the corresponding dorsal aspect at baseline. Cystotomy site thickening peaked 1 day after surgery and decreased at subsequent visits in a linear manner. Twelve weeks after surgery, 5 of 10 clinically normal dogs evaluated had persistent cystotomy site thickening. Eleven of 18 dogs had reoccurrence of hyperechoic foci within the bladder at some time during the study (median time to first detection, 17 days after surgery). CONCLUSIONS AND CLINICAL RELEVANCE Persistent cystotomy site thickening can be present up to 3 months after cystotomy for urolithiasis in dogs without lower urinary tract signs. Reoccurrence of hyperechoic foci in the bladder, although subclinical, was detected earlier and at a higher rate than anticipated.

Evaluation of a quantitatively derived value for assessment of muscle mass in clinically normal cats.

OBJECTIVE To evaluate use of an ultrasonographically and radiographically determined value, the vertebral epaxial muscle score (VEMS), for assessing muscle mass in cats. ANIMALS 30 healthy neutered cats of various body weights and between 1 and 6 years of age. PROCEDURES Mean epaxial muscle height was calculated from 3 transverse ultrasonographic images obtained at the level of T13. Length of T4 was measured on thoracic radiographs, and the VEMS (ratio of epaxial muscle height to T4 length) was calculated and compared with body weight. Ratios of epaxial muscle height to various anatomic measurements also were compared with body weight as potential alternatives to use of T4 length. RESULTS 1 cat was excluded because of a heart murmur. For the remaining 29 cats, mean ± SD body weight was 5.05 ± 1.40 kg. Mean epaxial muscle height was 1.27 ± 0.13 cm, which was significantly correlated (r = 0.65) with body weight. The VEMS and value for epaxial muscle height/(0.1 × forelimb circumference) were not significantly correlated (r = -0.18 and -0.06, respectively) with body weight, which is important for measures used for animals of various sizes. CONCLUSIONS AND CLINICAL RELEVANCE The VEMS and value for epaxial muscle height/(0.1 × forelimb circumference) can both be used to normalize muscle size among cats of various body weights. Studies are warranted to determine whether these values can be used to accurately assess muscle mass in cats with various adiposity and in those with muscle loss.

Survey of veterinary specialists regarding their knowledge of radiation safety and the availability of radiation safety training.

OBJECTIVE To evaluate the knowledge of various veterinary specialists regarding various radiation safety matters and determine the availability of radiation safety training. DESIGN Cross-sectional study. SAMPLE 164 radiology, 81 internal medicine, and 108 emergency and critical care (ECC) specialists. PROCEDURES An online survey was developed regarding knowledge of and training in radiation safety, and invitations were sent via email through the email lists of the veterinary internal medicine, ECC, and radiology specialty colleges. Responses were summarized, and comparisons were made between radiologists and internal medicine and ECC clinicians. RESULTS 65.5% (38 /58) of respondents from academic institutions and 30.0% (33/110) of respondents from private practices indicated that radiation safety training was mandatory at their institution for personnel who work with ionizing radiation-emitting equipment, and 80.2% (85/106) and 56.6% (77/136), respectively, had received some radiation safety training. Low proportions of radiologists and internal medicine and ECC clinicians correctly identified the effective dose of ionizing radiation associated with 3-phase esophagography and 3-phase abdominal CT. Many radiologists (92/153 [60.1%]) and nonradiologists (92/179 [51.4%]) believed that the effective doses used in veterinary practice pose no increased risk of fatal cancer to their patients. CONCLUSIONS AND CLINICAL RELEVANCE Radiation safety training, although more common in academia, was not universally available and may not meet radiography equipment license requirements for some institutions. Most radiologists, internal medicine clinicians, and ECC clinicians had a poor understanding of the amount of ionizing radiation associated with medical imaging procedures and the potential hazards to their patients.

Quantitative assessment of muscle in dogs using a vertebral epaxial muscle score.

Muscle loss associated with disease (cachexia) or with aging (sarcopenia) is common in dogs, but clinically relevant methods for quantifying muscle loss are needed. We previously validated an ultrasound method of quantifying muscle size in dogs in a single breed. The goal of this study was to assess the variability and reproducibility of the Vertebral Epaxial Muscle Score (VEMS) in other dog breeds. Static ultrasound images were obtained from 38 healthy, neutered dogs of 5 different breeds between 1- and 5-years-old. The maximal transverse right epaxial muscle height and area at the level of the 13th thoracic vertebra (T13) were measured. Length of the 4th thoracic vertebra (T4) was measured from thoracic radiography. Ratios of the muscle height and area to vertebral length (height/T4 and area/T4, respectively) were calculated to account for differences in body size among breeds. Reproducibility testing was performed on 2 dogs of each breed (26% of the total) to determine intra- and inter-investigator reproducibility, as well as intra-class correlation. Mean height/T4 = 1.02 ± 0.18 and mean area/T4 = 3.32 ± 1.68. There was no significant difference for height/T4 (P = 0.10) among breeds, but breeds were significantly different in area/T4 (P < 0.001). Intra-class correlation ranged from 0.80 to 0.99. Testing showed better reproducibility for height/T4 compared to area/T4. The VEMS using height/T4 was valid and reproducible for healthy dogs of different sizes and body conformations. Studies assessing this technique in dogs with congestive heart failure and other diseases associated with muscle loss are warranted.

La perte musculaire associée à la maladie (cachexie) ou à l'âge (sarcopénie) est fréquente chez les chiens, mais des méthodes appropriées pour quantifier en clinique la perte de muscle sont requises. Nous avons validé précédemment une méthode par échographie pour quantifier la taille musculaire chez des chiens d'une seule race. L'objectif de la présente étude était d'évaluer la variabilité et la reproductibilité du pointage du muscle épi-axial vertébral (PMEV) chez d'autres races de chien. Des images échographiques statiques furent obtenues de 38 chiens stérilisés en santé de cinq races différentes et âgés entre 1 et 5 ans. La hauteur transverse maximale du muscle épi-axial droit et la surface à la hauteur de la 13e vertèbre thoracique (T13) ont été mesurées. La longueur de la 4e vertèbre thoracique (T4) a été mesurée à partir de radiographies thoraciques. Les ratios de la hauteur du muscle et de la surface à la longueur de la vertèbre (hauteur/T4 et surface/T4, respectivement) ont été calculés pour tenir compte des différences de la taille entre les différentes races. Un test de reproductibilité a été effectué chez deux chiens de chaque race (26 % du total) afin de déterminer la reproductibilité intra- et inter-investigateur, ainsi que la corrélation intra-classe. La moyenne du ratio hauteur/T4 était de 1,02 ± 0,18 et la moyenne du ratio surface/T4 était de 3,32 ± 1,68. Il n'y avait pas de différence significative parmi les races pour le ratio hauteur/T4 (P = 0,10), mais les races différaient significativement pour ce qui est du ratio surface/T4 (P < 0,001). Les corrélations intra-classes variaient entre 0,80 et 0,99. Les tests ont montré une meilleure reproductibilité pour le ratio hauteur/T4 comparativement au ratio surface/T4. Le PMEV utilisant le ratio hauteur/T4 était valide et reproductible pour des chiens en santé de différentes tailles et conformations corporelles. Des études évaluant cette technique chez de chiens avec une défaillance cardiaque congestive et autres maladies associées avec de la perte musculaire sont justifiées. (Traduit par Docteur Serge Messier).

Association between subcutaneous fat thickness measured on thoracic radiographs and body condition score in dogs.

OBJECTIVE: To determine whether subcutaneous fat thickness measured on thoracic radiographs was associated with body condition score (BCS) in dogs. Animals-87 client-owned dogs (41 males and 46 females) with a median age of 10.0 years (range, 1 to 16 years) and median weight of 20.3 kg (range, 3.1 to 58.0 kg). PROCEDURES: Age, sex, body weight, and breed were recorded. Body condition scores (scale from 1 to 9) and muscle condition scores were assigned by a single investigator. Subcutaneous fat thickness was measured at the level of the eighth rib head on a dorsoventral or ventrodorsal radiographic view of the thorax by a single investigator. Ratios of subcutaneous fat thickness to the width of the midbody of T8 on the ventrodorsal or dorsoventral radiographic view (T8 ratio) and to the length of the midbody of T4 on a right lateral radiographic view (T4 ratio) were calculated and compared with BCS by means of the Spearman correlation method. RESULTS: Median BCS was 6 (range, 1 to 9), and all muscle condition scores were represented. There were significant correlations between BCS and T4 ratio (r = 0.86) and between BCS and T8 ratio (r = 0.84). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that in this population, there was a significant association between BCS and subcutaneous fat thickness measured on thoracic radiographs. Findings suggested that measuring subcutaneous fat thickness could aid in the retrospective assignment of BCS in studies involving dogs in which BCS was not recorded in the medical record.

Brain structural abnormalities in Doberman pinschers with canine compulsive disorder.

Obsessive compulsive disorder (OCD) is a debilitating condition, the etiology of which is poorly understood, in part because it often remains undiagnosed/untreated for a decade or more. Characterizing the etiology of compulsive disorders in animal models may facilitate earlier diagnosis and intervention. Doberman pinschers have a high prevalence of an analogous behavioral disorder termed canine compulsive disorder (CCD), which in many cases responds to treatments used for OCD. Thus, studies of CCD may help elucidate the etiology of compulsive disorders. We compared brain structure in Dobermans with CCD (N=8) and unaffected controls (N=8) to determine whether CCD is associated with structural abnormalities comparable to those reported in humans with OCD. We obtained 3 Tesla magnetic resonance structural and diffusion images from anesthetized Dobermans and subjected images to segmentation, voxel based morphometry, and diffusion tensor analyses. CCD dogs exhibited higher total brain and gray matter volumes and lower dorsal anterior cingulate cortex and right anterior insula gray matter densities. CCD dogs also had higher fractional anisotropy in the splenium of the corpus callosum, the degree of which correlated with the severity of the behavioral phenotype. Together, these findings suggest that CCD is associated with structural abnormalities paralleling those identified in humans with OCD. Accordingly, the CCD model, which has a number of advantages over other animal models of OCD, may assist in establishing the neuroanatomical basis for and etiology of compulsive disorders, which could lead to earlier diagnosis of and new treatments for humans and animals with these disorders.

Magnetic resonance imaging metallic artifact of commonly encountered surgical implants and foreign material.

Magnetic resonance imaging (MRI) artifacts secondary to metallic implants and foreign bodies are well described. Herein, we provide quantitative data from veterinary implants including total hip arthroplasty implants, cranial cruciate repair implants, surgical screws, a skin staple, ligation clips, an identification microchip, ameroid constrictor, and potential foreign bodies including air gun and BB projectiles and a sewing needle. The objects were scanned in a gelatin phantom with plastic grid using standardized T2-weighted turbo-spin echo (TSE), T1-weighted spin echo, and T2*-weighted gradient recalled echo (GRE) image acquisitions at 1.5 T. Maximum linear dimensions and areas of signal voiding and grid distortion were calculated using a DICOM workstation for each sequence and object. Artifact severity was similar between the T2-weighted TSE and T1-weighted images, while the T2*-weighted images were most susceptible to artifact. Metal type influenced artifact size with the largest artifacts arising from steel objects followed by surgical stainless steel, titanium, and lead. For animals with metallic surgical implants or foreign bodies, the quantification of the artifact size will help guide clinicians on the viability of MRI.