Case Description—A gallbladder mucocele was diagnosed in 2 dogs. In both dogs, the mucocele resolved with medical treatment but without the need for surgical intervention.
Clinical Findings—A 12-year-old spayed female Miniature Schnauzer had a history of signs of gastrointestinal tract disease and high serum liver enzyme activities. Gallbladder mucocele and hypothyroidism were diagnosed. A 6-year-old neutered mixed-breed dog had chronic intermittent diarrhea and recurrent otitis; gallbladder mucocele and hypothyroidism were diagnosed.
Treatment and Outcome—The first dog was treated with S-adenosyl-methionine, omega-3 fatty acids, famotidine, ursodiol, and levothyroxine. Substantial improvement in the gastrointestinal tract condition and complete resolution of the gallbladder mucocele within 3 months were evident, but the dog was not available for further follow-up monitoring. The second dog was treated with fenbendazole, ursodiol, and levothyroxine and fed a hypoallergenic diet. One month after evaluation, abdominal ultrasonography revealed that the gallbladder mucocele was resolving, and treatment was continued. Ultrasonographic evaluation 2 and 4 months later revealed complete resolution of the mucocele.
Clinical Relevance—Review of the clinical course of 2 dogs in which there was nonsurgical resolution of gallbladder mucocele revealed that surgery is not necessary in all dogs with gallbladder mucocele. Hypothyroidism may have resulted in delayed gallbladder emptying, and its role in the pathogenesis of gallbladder mucocele merits investigation. Despite this information, until further prospective trials with a control group and standardized treatments and follow-up monitoring can be performed, the authors recommend surgical intervention for treatment of dogs with gallbladder mucocele.
Objective—To evaluate the clinical signs, diagnosis, treatment, and outcome associated with distal interphalangeal joint (DIJ) degenerative disease in calves.
Design—Retrospective case series.
Animals—9 calves with degenerative disease of the DIJ.
Procedures—Medical records of calves with lameness for which the cause had been localized to the distal aspect of a limb but without evidence of trauma or sepsis were included. Signalment and results of physical, lameness, radiographic, and postmortem examinations were recorded. Outcomes of medical and surgical treatments were evaluated.
Results—All 9 calves had forelimb lameness (4 bilaterally). The medial digit was affected in 12 limbs and the lateral digit was affected in 9 limbs. Radiographic examination revealed bridging osteoproliferation along the abaxial and palmar aspects of affected DIJs (18/21), subchondral cyst-like lucencies (19/21), and sclerosis (16/21). The DIJ was resected in 3 calves (7 joints), resulting in resolution of lameness within 3 months. Medical management was attempted in 4 calves (6 joints), and 2 calves (6 joints) did not receive treatment; 5 calves had a normal stance within 5 months. Results of postmortem com-puted tomographic and histologic examination were in accordance with degenerative joint disease processes.
Conclusions and Clinical Relevance—Degenerative disease of the DIJ should be considered in calves with insidious, progressive forelimb lameness. Although the etiology of this process remains undetermined, results of radiographic, computed tomographic, and histologic examinations suggested an underlying developmental anomaly, such as osteochondrosis. Surgical treatment appeared promising on the basis of postop-erative resolution of lameness in all surgically treated calves.
Objective—To evaluate the ability of signal attenuation–based quantitative magnetic resonance imaging (QMRI) to estimate subchondral bone mineral density (BMD) as assessed via quantitative computed tomography (QCT) in osteoarthritic joints of horses.
Sample Population—20 metacarpophalangeal joints from 10 horse cadavers.
Procedures—Magnetic resonance (MR) images (dorsal and transverse T1-weighted gradient recalled echo [GRE] and dorsal T2*-weighted GRE fast imaging employing steady-state acquisition [T2*-FIESTA]) and transverse single-slice computed tomographic (CT) images of the joints were acquired. Magnetic resonance signal intensity (SI) and CT attenuation were quantified in 6 regions of interest (ROIs) in the subchondral bone of third metacarpal condyles. Separate ROIs were established in the air close to the joint and used to generate corrected ratios and SIs. Computed tomographic attenuation was corrected by use of a calibration phantom to obtain a K2HPO4-equivalent density of bone. Correlations between QMRI performed with different MR imaging sequences and QCT measurements were evaluated. The intraobserver repeatability of ROI measurements was tested for each modality.
Results—Measurement repeatability was excellent for QCT (R2 = 98.3%) and QMRI (R2 = 98.8%). Transverse (R2 = 77%) or dorsal (R2 = 77%) T1-weighted GRE and QCT BMD measurements were negatively correlated, as were dorsal T2*-FIESTA and QCT (R2 = 80%) measurements. Decreased bone SI during MR imaging linearly reflected increased BMD.
Conclusions and Clinical Relevance—Results of this ex vivo study suggested that signal attenuation–based QMRI was a reliable, clinically applicable method for indirect estimation of subchondral BMD in osteoarthritic metacarpophalangeal joints of horses.
Case Description—A 1-year-old female spayed Labrador Retriever was admitted for evaluation of a progressive gait disturbance characterized by tetraparesis and general proprioceptive ataxia in all limbs.
Clinical Findings—Neurologic examination suggested a dysfunction of the C6-T2 spinal cord segments, which was slightly worse on the right side. Discomfort was suspected upon lateral flexion of the neck. Two magnetic resonance imaging (MRI) examinations at a 3-week interval revealed an intramedullary fluid-filled cavitary lesion adjacent to C7, containing a blood clot.
Treatment and Outcome—Following unsuccessful initial conservative management, surgical marsupialization of the lesion was performed through a dorsal laminectomy, durotomy, and myelotomy at C6 and C7. Histologic evaluation including immunohistochemistry was diagnostic for a vascular anomaly. Initially, the dog was nonambulatory with tetraparesis and became tetraplegic after surgery; movement was regained 6 days later. Four weeks after the procedure, the dog was able to walk unassisted. One year after surgery, the dog was actively running and jumping, with mild residual ataxia in the pelvic limbs.
Clinical Relevance—The intramedullary vascular anomaly in this dog was successfully treated with a surgical marsupialization technique. The combination of MRI, histologic eval-uation, and immunohistochemistry enabled lesion localization, evaluation of cavity content, and final diagnosis.
Objective—To determine prevalence of various radiographic signs in cats with feline bronchial disease (FBD) and evaluate intra- and interobserver variability in radiographic interpretation for examiners with variable degrees of experience in radiographic interpretation.
Design—Retrospective case series.
Animals—40 cats with FBD and 40 control cats without thoracic disease.
Procedures—Radiographic abnormalities in cats with FBD were scored by consensus of 2 radiologists. Radiographs of control cats and cats with FBD were examined twice by 5 other individuals, and diagnostic accuracy and observer agreement were assessed.
Results—In cats with FBD, the most common radiographic signs were bronchial (n = 37) and unstructured interstitial (30) lung patterns, lung hyperinflation (31) and hyperlucency (21), aerophagia (19), and lung soft tissue opacities (11). Ratios of lung inflation on ventrodorsal views were significantly higher in cats with FBD. For the 5 examiners, sensitivity ranged from 71% to 89% and specificity ranged from 43% to 74%. Intraobserver agreement was good (N = 0.47 to 0.60), but the agreement between examiners was only poor to good (N = 0.22 to 0.70). For most examiners, significant associations were found between examiner diagnosis (correct vs incorrect), level of examiner certainty, and bronchial pattern severity.
Conclusions and Clinical Relevance—Findings suggested that several radiographic abnormalities can commonly be seen in cats with FBD but highlighted the limitations of thoracic radiography. Examiner diagnosis and level of confidence were significantly associated with severity of a bronchial pattern.
Objective—To evaluate interobserver agreement and diagnostic accuracy of brain MRI in dogs.
Procedures—5 board-certified veterinary radiologists with variable MRI experience interpreted transverse T2-weighted (T2w), T2w fluid-attenuated inversion recovery (FLAIR), and T1-weighted-FLAIR; transverse, sagittal, and dorsal T2w; and T1-weighted-FLAIR postcontrast brain sequences (1.5 T). Several imaging parameters were scored, including the following: lesion (present or absent), lesion characteristics (axial localization, mass effect, edema, hemorrhage, and cavitation), contrast enhancement characteristics, and most likely diagnosis (normal, neoplastic, inflammatory, vascular, metabolic or toxic, or other). Magnetic resonance imaging diagnoses were determined initially without patient information and then repeated, providing history and signalment. For all cases and readers, MRI diagnoses were compared with final diagnoses established with results from histologic examination (when available) or with other pertinent clinical data (CSF analysis, clinical response to treatment, or MRI follow-up). Magnetic resonance scores were compared between examiners with κ statistics.
Results—Reading agreement was substantial to almost perfect (0.64 < κ < 0.86) when identifying a brain lesion on MRI; fair to moderate (0.14 < κ < 0.60) when interpreting hemorrhage, edema, and pattern of contrast enhancement; fair to substantial (0.22 < κ < 0.74) for dural tail sign and categorization of margins of enhancement; and moderate to substantial (0.40 < κ < 0.78) for axial localization, presence of mass effect, cavitation, intensity, and distribution of enhancement. Interobserver agreement was moderate to substantial for categories of diagnosis (0.56 < κ < 0.69), and agreement with the final diagnosis was substantial regardless of whether patient information was (0.65 < κ < 0.76) or was not (0.65 < κ < 0.68) provided.
Conclusions and Clinical Relevance—The present study found that whereas some MRI features such as edema and hemorrhage were interpreted less consistently, radiologists were reasonably constant and accurate when providing diagnoses.