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Invasive urothelial (transitional cell) carcinoma (UC) is the most common cancer in the canine urinary tract. Prolonged survival of dogs with UC due to better management of the primary tumor and prevention of urethral obstruction might have contributed to an apparent increase in distant metastasis. Metastasis to bone is particularly concerning because the ensuing pain often leads to euthanasia; however, little is known of the frequency, site, or nature of UC skeletal metastasis. In a retrospective analysis, 17 (9%) of 188 canine UC cases had histologically confirmed skeletal metastasis, mainly to the vertebrae. In a prospective analysis of 21 dogs with UC that underwent total body computed tomography (CT) at euthanasia followed by a standardized pathologic examination, skeletal lesions detected on CT were suspected to be metastatic in 4 dogs and were confirmed as metastatic UC histologically in 3 (14%) dogs. In all 3 cases, skeletal metastasis had been suspected based on history and physical examination; however, 1 dog had additional CT-detected skeletal metastases in a clinically unsuspected location, and 2 dogs had histologically confirmed skeletal metastases that corresponded to nonspecific osseous lesions on CT. These findings suggest that total body CT could be helpful in detecting skeletal metastasis as a cause of bone pain in dogs with UC as well as in identifying clinically "silent" sites of skeletal metastasis.

X-ray computed tomography (CT) is currently one of the most powerful, noninvasive, clinical in vivo imaging techniques, which has resulted from advances in both X-ray device and contrast enhancement technologies. The present study demonstrates, for the first time, that metal tungstates (such as CaWO 4 ) are promising contrast agents for X-ray, radiation, and CT imaging, because of the high X-ray mass attenuation of tungsten (W). We have developed a method of formulation, in which CaWO 4 (CWO) nanoparticles (NPs) are encapsulated within a biocompatible poly(ethylene glycol-b-d,l-lactic acid) (PEG-PLA) block copolymer (BCP) capsule. We show that these PEG-PLA-encapsulated CWO NPs (170 ± 10 nm hydrodynamic diameter) produce a higher CT contrast (by a factor of about 2) than commercial iodine-based radiocontrast agents (e.g., Iohexol) at identical molar concentrations of W or I atoms. PEG-PLA-coated CWO NPs are chemically stable and completely nontoxic. It was confirmed that the maximum tolerated dose (MTD) of this material in mice is significantly higher (250 ± 50 mg per kg body weight following a single intravenous (IV) administration) than, for instance, commercially available dextran-coated iron oxide nanoparticles that are currently used clinically as MRI contrast agents (MTD in mice ≈ 168 mg/kg per dose IV). IV-injected PEG-PLA/CWO NPs caused no histopathologic damage in major excretory organs (heart, liver, lungs, spleen, and kidney). When an IV dose of 100 mg/kg was given to mice, the blood circulation half-life was measured to be about 4 h, and more than 90% of the NPs were cleared from the mice within 24 h via the renal and hepatobiliary systems. When intratumorally administered, PEG-PLA-coated CWO NPs showed complete retention in a tumor-bearing mouse model (measurements were made up to 1 week). These results suggest that PEG-PLA-coated CWO NPs are promising materials for use in CT contrast.

Published information regarding canine vertebral column mast cell tumors (MCTs) is limited. The objectives of this study were to report clinical and advanced imaging findings for a group of dogs with confirmed spinal MCT. Inclusion criteria for this retrospective case series were dogs with spinal magnetic resonance imaging (MRI) or computed tomography (CT) scans and a histological diagnosis of spinal MCT. Clinical, imaging, treatment, and outcome data were recorded. Four dogs met inclusion criteria. One dog had primary spinal MCT and three dogs had metastatic spinal MCT. All four dogs presented for paraspinal hyperesthesia and subacute progressive or acute myelopathy. All CT and MRI lesions were extradural. Two cases exhibited distinct masses in the epidural space. In one case, an epidural tumor invaded from the paravertebral musculature. One case exhibited polyostotic lesions indistinguishable from multiple myeloma by MRI. One dog with a primary epidural low-grade MCT remains clinically normal 4 years postoperatively, following adjunctive lomustine. An epidural high-grade MCT, metastatic from a cutaneous tumor, recurred within 2 months of surgery despite adjunctive vinblastine. Two high-grade cases with concurrent visceral involvement were euthanized immediately after imaging. In dogs, MCT should be considered as a differential diagnosis for a progressive painful myelopathy and CT or MRI evidence of an extradural spinal lesion (epidural, paravertebral, or polyostotic). While more often associated with cutaneous or disseminated disease, MCT may also occur as a primary tumor of the epidural space in dogs., (© 2016 American College of Veterinary Radiology.)

The primary study objective was to determine whether clinical examination and magnetic resonance imaging (MRI) can underestimate canine gliomatosis cerebri (GC); we also investigated immunohistochemical features. Seven dogs with GC were studied; four recruited specifically because of minimal MRI changes. Neuroanatomic localization and the distribution of MRI, gross and sub-gross lesions were compared with the actual histological distribution of neoplastic cells. In six cases, clinical examination predicted focal disease and MRI demonstrated a single lesion or appeared normal. Neoplastic cells infiltrated many regions deemed normal by clinical examination and MRI, and were Olig2-positive and glial fibrillary acid protein-negative. Four dogs had concurrent gliomas. GC is a differential diagnosis for dogs with focal neurological deficits and a normal MRI or a focal MRI lesion. Canine GC is probably mainly oligodendrocytic. Type II GC, a solid glioma accompanying diffuse central nervous system neoplastic infiltration, occurs in dogs as in people., (© 2014 John Wiley & Sons Ltd.)

The muscularis layer of the canine colon has been reported to appear homogeneously hypoechoic on ultrasonography. A hyperechoic band in the muscularis layer paralleling the serosal surface has been observed by authors in routine canine abdominal ultrasound examinations. The purpose of this prospective and retrospective cross-sectional study was to determine the prevalence of this lesion, characterize its ultrasonographic and postmortem histologic features, and correlate its presence with clinical signs of gastrointestinal disease. In the prospective study, all dogs that underwent routine abdominal ultrasonography by one of two observers during a 4-week period were included without any exclusion criteria. One observer reviewed ultrasound images and recorded the presence or absence of this lesion and its distribution, e.g. focal (< 2 cm long) or diffuse (> 2 cm long). In the retrospective study, all dogs that had both abdominal ultrasonography and necropsy from January 2011 to December 2013 were included without any exclusion criteria. Histologic examinations were performed by two observers and Masson's trichrome stain was used to identify fibrous collagen. Prevalence for the hyperechoic band was 32% in the prospective and 4.8% in the retrospective sample populations, respectively. The hyperechoic band appeared as diffuse, focal, or a combination of both. Histologic sections were available for six dogs. In a few cases, the lesion corresponded to the presence of fibrous tissue in the myenteric plexus or in the tunica muscularis. None of the dogs had a history of diarrhea. Findings supported the hypothesis that a colonic muscularis hyperechoic band paralleling the serosal layer in dogs could be a normal variant rather than a marker of disease., (© 2015 American College of Veterinary Radiology.)

Objective: To develop a model of hip joint synovitis on the basis of intra-articular injection of a sodium urate suspension in dogs and to characterize associated gait changes., Animals: 6 healthy adult dogs., Procedures: Each dog was sedated, and synovitis was induced by injection of 1 mL of a sodium urate suspension (20 mg/mL) into the right hip joint under ultrasonographic guidance. Observational and instrumented gait analyses to determine temporospatial, kinetic, and kinematic variables were performed prior to and 4, 8, and 24 hours after sedation and synovitis induction., Results: Injection of a sodium urate suspension into the hip joint of healthy dogs resulted in lameness of the ipsilateral pelvic limb as determined by observational and instrumented gait analyses. For all dogs, lameness was clinically detectable within 1.5 to 2 hours after injection, reached its maximum intensity at 4 hours after injection, and had subsided by 24 hours after injection., Conclusions and Clinical Relevance: Results indicated that injection of a sodium urate suspension into the hip joint of healthy dogs reliably induced synovitis and signs of pain and lameness in the ipsilateral pelvic limb that lasted 24 hours. This model can be used in conjunction with instrumented gait analysis to provide information on gait changes associated with hip joint disease and might be useful for evaluating the efficacy of analgesics or other interventions for the treatment of hip joint disease in dogs.

Little published information is available to guide therapy for canine and feline patients with Coccidioides infections involving the central nervous system (CNS). The purpose of this cross-sectional retrospective study was to describe magnetic resonance imaging (MRI) features and outcome for a group of dogs and cats with solitary CNS Coccidiodes granulomas. Nine canine and two feline cases met inclusion criteria; four diagnosed and treated with surgery and fluconazole and seven diagnosed by serology or cytology and treated medically. Three cases had left Coccidioides endemic areas long before developing neurological disease. The MRI lesions shared many features with neoplastic masses. The extra-axial granulomas often had a lack of a distinct border between the mass and neural parenchyma. Four cases were extra-axial and seven were intra-axial, but distinguishing between extra-axial and intra-axial locations was sometimes challenging. The surgical cases had good outcomes and histology allowed definitive diagnosis. Medically managed patients also had generally good outcomes, with resolution of clinical signs in most cases. Findings indicated that distinction between neoplasia and focal Coccidioides granulomas based on MRI features is likely to be imprecise. Demonstration of the organism by cytology or histology is required for definitive diagnosis. The role of surgery for improving the outcome of brain or spinal coccidioidomycosis granulomas warrants further study., (© 2015 American College of Veterinary Radiology.)

Background: The effect of feeding a limited iodine diet on radioactive iodine uptake in the thyroid glands of hyperthyroid cats is unknown., Objectives: To determine how feeding limited dietary iodine affects radioactive iodine uptake by the thyroid glands of hyperthyroid cats., Animals: Eight geriatric cats with spontaneous hyperthyroidism., Methods: Prospective study of eight client owned hyperthyroid cats fed a commercially available iodine limited diet for 6 months. Clinical signs were evaluated and TT4 and fT4 were measured during consumption of the diet. Uptake of (123)I was determined before and 8-16 weeks after exclusive consumption of the diet., Results: Clinical signs of hyperthyroidism resolved in all cats, but there was no significant increase in body weight. TT4 and fT4 decreased into the reference range by 8-16 weeks in all cats. Mean TT4 before consumption of the diet was 9.7 μg/dL (SD 5.2) and after consumption of the diet was 3.1 μg/dL (SD 0.9). Scintigraphy revealed unilateral uptake of isotope in 5 cats and bilateral uptake in 3 cats. Mean percentage uptake of (123)I by the thyroid gland at 8 hours after isotope administration was 16.2 (SD 11.8) before diet consumption and 34.6 (SD 11.7) 8-16 weeks after exclusive consumption of the diet. The percentage increase was variable between cats (38-639%)., Conclusions and Clinical Importance: Limited iodine diets increase iodine uptake in the autonomous thyroid glands of hyperthyroid cats. Further studies are necessary to determine if consumption of a limited iodine diet changes sensitivity of the thyroid gland to (131)I treatment., (Copyright © 2015 by the American College of Veterinary Internal Medicine.)

Objective: To evaluate the association between ultrasonographically measured optic nerve sheath diameter (ONSD) and acute increases in intracranial pressure (ICP) as measured by an epidural intracranial pressure monitoring system (EICPMS) in healthy dogs., Animals: 6 young healthy dogs., Procedures: An EICPMS connected to a pressure monitor was used to generate a continuous pressure waveform in each anesthetized dog. A 22-gauge IV catheter was inserted into the brain parenchyma through the contralateral parietal bone, and 0.5 to 2.0 mL of anticoagulated autologous blood was injected at predetermined intervals. At baseline (immediately after EICPMS placement) and following each injection, the ICP as indicated by EICPMS was recorded, and 3 ultrasonographic images of the optic nerve sheath of each eye were obtained. The ONSD was measured at maximum diameter and at 5 mm caudal to the optic disk., Results: In linear models, the maximum ONSD was positively associated with increasing ICP. Specifically, the rate of maximum ONSD increase was greater for pressures ≤ 20 mm Hg above baseline (0.0534 mm/1 mm Hg ICP increase) than for pressures > 40 mm Hg above baseline (0.0087 mm/1 mm Hg ICP increase). The relationship of ICP to maximum ONSD was slightly nonlinear and best explained by comparison of fractional polynomial regression models., Conclusions and Clinical Relevance: ICP was positively and nonlinearly associated with increasing maximum ONSD, especially when ICP was ≤ 20 mm Hg above baseline, supporting the conclusion that ultrasonographic measurement of maximum ONSD may provide a noninvasive monitoring tool for evaluation of ICP in dogs. Further research is needed to assess the utility of these measurements in clinical patients.

Objective: To compare ultrasound biomicroscopy (UBM) with standard ocular ultrasonography for detection of canine uveal cysts and to determine the sensitivity, specificity, and interobserver agreement for detection of uveal cysts with UBM., Sample: 202 enucleated eyes from 101 dogs., Procedures: 2 examiners examined 202 eyes by means of UBM (50 MHz) to identify uveal cysts. A board-certified radiologist then examined 98 of the 202 eyes by means of standard ocular ultrasonography (7- to 12-MHz linear transducer). Subsequently, 1 examiner dissected all 202 eyes under magnification from an operating microscope to definitively identify uveal cysts. Each examiner was masked to other examiners' findings. Sensitivity, specificity, and interobserver agreement were calculated for detection of cysts by UBM., Results: Cysts were detected by use of UBM in 55 of 202 (27%) eyes by one examiner and 29 of 202 (14%) eyes by the other. No cysts were detected in the 98 eyes examined with standard ocular ultrasonography. Dissection results revealed that cysts were present in 64 of 202 (32%) eyes, including 29 of 98 (30%) eyes examined by standard ocular ultrasonography. Mean sensitivity of UBM for cyst detection was 47%; mean specificity was 92%. Uveal cysts not identified with UBM were often small (mean diameter, 490 üm). Interobserver agreement was high (κP = 0.81)., Conclusions and Clinical Relevance: UBM was more effective than standard ocular ultrasonography for detection of uveal cysts in enucleated eyes. Small-diameter cysts were difficult to visualize even with UBM.

A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and vomiting. On physical examination, the dog was painful on abdominal palpation. A torsed intra-abdominal testis was diagnosed via abdominal ultrasonography and radiography. Laparoscopy was used to identify and remove the torsed testis. The dog recovered uneventfully and was described as doing well by the owners at the 6 mo follow-up telephone contact. This is the first report of an abdominal testicular torsion treated with laparoscopy.

Uterus masculinus (persistent Mullerian duct) is a vestigial embryological remnant of the paramesonephric duct system in males and has been associated with clinical signs such as dysuria, incontinence, tenesmus and urethral obstruction in dogs. The radiological appearance of cystic uterus masculinus in dogs has been described previously with the aid of retrograde positive or negative contrast cystography. The purpose of this retrospective study was to describe ultrasonographic features of confirmed or presumed uterus masculinus in a group of dogs with confirmed or presumed disease. Ultrasonographic findings were recorded based on a consensus opinion of two readers. A uterus masculinus was defined as cylindrical when no lumen was observed and tubular when it had lumen that was filled with anechoic fluid. Six dogs met the inclusion criterion with a mean age of 8 years and 9 months. Uterus masculinus appeared as single (four dogs) or two (two dogs) horn-like, tubular (four dogs) or cylindrical (two dogs) structures, originating from the craniodorsal aspect of the prostate gland and extending cranially. The walls of the uterus masculinus were isoechoic to the urinary bladder wall. The diameter of the observed uterus masculinus varied from 0.3 cm to 1 cm. The length of the uterus masculinus varied from 2 cm to 6.5 cm but the cranial terminal end was not identified in two dogs. Concomitant prostatomegaly was seen in five dogs (83.3%) and urinary tract infection was noted in three dogs (50%). Findings indicated that uterus masculinus should be included as a differential diagnosis for male dogs with these ultrasonographic characteristics., (© 2014 American College of Veterinary Radiology.)

Objective: To describe the prevalence, location and clinical significance of abnormal gas accumulations in dogs and cats detected on computerised tomography images., Methods: Retrospective evaluation of all canine and feline computed tomography examinations (292 pre-contrast and 219 post-contrast) performed in a 12-month time period. All studies were evaluated for the presence of venous air emboli. The location of intravenous gas was noted and the volume of intravenous air emboli was estimated visually. The medical records of animals with venous air embolism were reviewed for signs of cardiopulmonary complications., Results: The overall prevalence of air embolism on pre- and incidence on post-contrast images was 4 · 5 and 2 · 3%, respectively. The prevalence of air embolism on pre-contrast and incidence on post-contrast thoracic images was 35 · 7 and 14 · 2%, respectively. The volume of venous air was generally small and the most common was in an axillary vein. None of the animals had any cardiopulmonary complications., Clinical Significance: The presence of small volume venous air embolism on routine computed tomography examinations is a frequent incidental finding that does not appear to cause cardiopulmonary complications., (© 2014 British Small Animal Veterinary Association.)

The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspected to have renal dysfunction. Focal increases in echogenicity have been attributed to neoplasia, infection, calcification, fibrosis, gas, and infarction. Anisotropic backscatter has been described as a source of focally increased renal cortical echogenicity in several species. The source of anisotropy appears to be the medullary rays, which are oriented perpendicular to the renal capsule. Spatial compound imaging (SCI) is an ultrasound setting that uses beam steering to acquire and average several overlapping scans of an object from different view angles, creating a compound image that is updated in real time. The impact of insonation angle and SCI on renal cortical echogenicity was evaluated ex vivo in eight kidneys from four dogs. Significant angle-dependent differences in cortical echogenicity were detected with both microconvex and linear transducers (P < 0.0001). Furthermore, the angle-dependent echogenicity differences persisted when SCI mode was used. Our finding that echogenicity was increased using a perpendicular insonation angle (90°) relative to the tubules, compared to a parallel insonation angle (0°) should assist in the interpretation of ultrasonographic images of the dog kidney., (© 2013 Veterinary Radiology & Ultrasound.)

Rapid detection of central nervous system (CNS) involvement is important for dogs with blastomycosis, as this can affect antifungal drug selection and has been associated with an increased risk of death. Previous reports describing magnetic resonance imaging (MRI) characteristics of canine CNS blastomycosis primarily identified mass lesions. The purpose of this retrospective study was to determine whether other MRI characteristics of CNS blastomycosis may also occur. Medical records of the Purdue University Veterinary Teaching Hospital were searched and four dogs met inclusion criteria. Magnetic resonance imaging characteristics included periventricular edema, periventricular and meningeal contrast enhancement, and ventriculomegaly. Periventricular lesions most commonly involved the rostral horn of the lateral ventricles and the third ventricle. Increased meningeal contrast enhancement involved the cerebrum, thalamus, sella turcica, and brainstem. Findings indicated that, in addition to mass lesions, MRI characteristics of periventricular hyperintensity, contrast enhancement, and ventriculomegaly may also occur in dogs with CNS blastomycosis., (© 2013 Veterinary Radiology & Ultrasound.)

Background: Clinical signs associated with respiratory tract disease are regularly encountered in people with kidney failure, and have been anecdotally reported in dogs., Objectives: To compare clinical signs indicative of pulmonary disease, clinicopathologic findings, radiographic abnormalities, and histologic findings in dogs with acute kidney injury (AKI) or International Renal Interest Society Stage 3 or 4 chronic kidney disease (CKD) to nonazotemic dogs. To determine associations between abnormalities indicative of pulmonary disease and outcome in azotemic dogs., Animals: One hundred sixty-seven pet dogs (54 AKI dogs, 50 CKD dogs, 63 nonazotemic control dogs diagnosed with intracranial disease)., Methods: Retrospective cohort study comparing signalment, clinical signs, clinicopathologic variables, prevalence, and severity of pulmonary radiographic patterns, histopathologic findings, and survival times in AKI, CKD, and control dogs., Results: Clinical signs of pulmonary disease were significantly more common in AKI dogs. Prevalence of an alveolar lung pattern was greater in AKI and CKD dogs. Alveolar mineralization was the most common pulmonary histologic lesion in AKI dogs (6 of 8 dogs), with concurrent alveolar concretions or mineralization of pulmonary vessels or bronchioles noted in 1 dog each; mineralization of lung tissues was not noted in control dogs. Neither clinical signs nor presence of an alveolar pattern were associated with likelihood of survival to discharge or median number of days from discharge until death., Conclusions and Clinical Importance: Abnormalities indicative of pulmonary disease are more common in azotemic dogs than in control dogs; however, prognosis is not associated with presence of clinical or radiographic pulmonary dysfunction., (Copyright © 2012 by the American College of Veterinary Internal Medicine.)

A 4-year-old male neutered Labrador Retriever with severe gastrointestinal signs, but no respiratory signs, was diagnosed with multifocal pyogranulomatous gastritis, enteritis, and lymphadenitis with intralesional hyphae and multifocal pyogranulomatous pneumonia with intralesional yeast. Based on cytologic evaluation, histologic examination with special stains, and immunohistochemical analysis of tissues collected antemortem or at necropsy, dual infections with Pythium insidiosum and Blastomyces dermatitidis were detected and are reported for the first time., (© 2012 American Society for Veterinary Clinical Pathology.)

In veterinary medicine, general anesthesia or sedation is generally required to immobilize patients during computed tomography (CT) scanning. This may not be suitable in all patients because of risks of anesthesia. We evaluated the feasibility of pelvic CT examination in 14 awake animals with pelvic trauma. Physical restraint was applied by wrapping the patient in a towel and then taping to the CT table or by directly taping the patient to the CT table. The effect of patient positioning, cooperation on the CT table, preparation time for scanning, scanning time, frequency of repeat scans, image quality, and complications related to physical restraint were evaluated. Fractures were recorded and compared between radiography and CT. Ten of 14 dogs were scanned in lateral recumbency and four in sternal recumbency. All patients were cooperative with the exception of one that moved slightly during the scan. Both physical restraint methods were adequate for CT scanning. Patient preparation took less than 5 min while the scan time was typically less than 1 min. No repeat scans were required in any patient. The transverse CT image quality was good (10/14) or fair (4/14) for interpretation. When comparing the CT images to radiographs, more pelvic fractures were identified with CT than with radiography and a few patients were overdiagnosed based on radiographs. No complications or additional injuries associated with physical restraint were noticed., (© 2012 Veterinary Radiology & Ultrasound.)

A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum., (© 2011 Veterinary Radiology & Ultrasound.)

Case Description: An 8-year-old 12.2-kg (26.9-lb) spayed female American Cocker Spaniel was referred for evaluation of abdominal discomfort and a suspected intra-abdominal lipoma with possible invasion into the thorax., Clinical Findings: Physical examination revealed a tense abdomen, and the margins of a large abdominal mass could be appreciated. Abdominal imaging revealed a mass of fat opacity in the abdominal and thoracic cavities. Computed tomography with precontrast and postcontrast peritoneograms was used to determine whether the masses connected via a diaphragmatic defect., Treatment and Outcome: Exploratory laparotomy revealed a retroperitoneal lipomatous mass that had focally invaded the hypaxial musculature and had extended across the dorsolateral aspect of the diaphragm via the lumbocostal trigone into the intrathoracic extrapleural space. Surgical resection required transdiaphragmatic thoracotomy. Histologic examination of excised tissue confirmed the preoperative diagnosis of a lipoma. The dog recovered from surgery with no complications and had no disease recurrence for at least 32 months after surgical resection., Clinical Relevance: The defect of the lumbocostal trigone is also called the foramen of Bochdalek in humans, and it is recognized as a common location for congenital diaphragmatic hernia. A lumbocostal trigone hernia may be considered as a differential diagnosis for bicavitary masses in dogs, particularly in the absence of a history of trauma.

Spatial compound sonography improves visualization of tissue details and allows clearer delineation of structural margins. Improved image clarity is due to reduced speckling artifact; however, other types of acoustic shadowing artifacts may be unchanged or variably altered when conventional and spatial compound sonographic images are compared. Because intrarenal distal shadowing artifacts in conventional sonographic images are oftentimes the first or only evidence that a nephroliths is present, we compared the appearance and associated artifacts of nephroliths examined with both imaging modes. Consensus evaluation by two evaluators confirmed differences in appearance of nephroliths based on imaging mode. Nephroliths with conventional imaging mode were less hyperechoic and had better margin delineation while nephroliths were more hyperechoic and had less distinct margins with spatial compound imaging mode. Distal acoustic shadowing artifacts were present in 43% of spatial compound imaging mode vs. 86% of conventional imaging mode. When present in both imaging modes, intensity of these artifacts was weaker and the distance traveled was shorter in spatial compound imaging mode. Multiple diverging acoustic shadowing artifacts originating from a single source, the nephroliths were occasionally noted in spatial compound but not conventional imaging mode. These results demonstrate that the absence of distal acoustic shadowing cannot be used to exclude the presence of a nephrolith in dogs and cats. Optimal diagnosis of nephroliths, margin delineation, and visualization of the distal renal parenchyma requires paired radiography and sonography, and alternating between sonographic imaging modes is therefore suggested.

Kidney biopsies in dogs are commonly obtained using automated spring-loaded biopsy instruments. Interpretation of biopsies from dogs with glomerular disease requires examination of at least 5-10 glomeruli, with at least two biopsies usually required for full evaluation. The purpose of this study was to compare quality and interpretability of renal biopsies obtained from healthy dogs with a large-gauge, vacuum-assisted biopsy instrument versus two biopsies obtained with a spring-loaded biopsy needle. Twenty dogs were randomized into two groups, and percutaneous, ultrasound-guided renal biopsies were evaluated using standard criteria. There were no significant differences in the number of biopsies that contained renal tissue, cortex, or medulla. Biopsies obtained with either instrument contained an adequate number of glomeruli and an equivalent number of arterioles and severity of tissue compression. Differences included easier penetration of the renal capsule and collection of sufficient tissue for interpretation with only one instrument pass when using the vacuum-assisted device (vs two passes required with the spring-loaded instrument). Before use in client-owned dogs, future studies should evaluate whether these differences are clinically relevant advantages in the diagnostic evaluation of dogs with kidney disease, and determine the prevalence and severity of complications when using this larger gauge device.

Case Description: A 6-month-old female domestic shorthair cat was admitted for evaluation of intermittent clinical signs of hematuria and inappropriate urination for the past 2 months., Clinical Findings: Transabdominal ultrasonography revealed a multilayered mass in the urinary bladder apex consistent with full-thickness invagination of the bladder wall., Treatment and Outcome: Exploratory surgery was performed, and partial inversion of the urinary bladder was confirmed. The invaginated bladder apex was manually reduced, and partial cystectomy was performed to remove the invaginated section of bladder wall. Histologic findings were consistent with vascular congestion and edema secondary to partial invagination. Bacterial culture of a section of the bladder mucosa demonstrated concurrent bacterial urinary tract infection. Clinical signs resolved following surgical resection of the bladder apex and antimicrobial treatment for the concurrent urinary tract infection., Clinical Relevance: Partial invagination of the urinary bladder should be considered in the differential diagnosis for cats with clinical signs of hematuria, stranguria, and inappropriate urination. A diagnosis may be made on the basis of detection of invaginated tissue in the bladder apex during abdominal ultrasonography.

We describe histopathologically confirmed intracranial metastasis of cutaneous lymphoma. In magnetic resonance (MR) images there was a heterogeneous, contrast-enhancing, extraaxial mass in the right parietal and piriform lobes at the level of the optic chiasm. Our MR imaging findings are consistent with reports in humans in that lymphoma masses have indistinct borders that are iso- to hyperintense relative to adjacent gray matter on T2-weighted images. Our report varies from findings in humans in that the mass was extraaxial, whereas masses reported in humans are intraaxial. Contrast enhancement can be heterogeneous, as in our report, or homogeneous., (© 2010 Veterinary Radiology & Ultrasound.)

Abdominal sonographic artifacts produced by conventional and spatial compound sonographic imaging using linear and curved array transducers were compared. Spatial compound imaging produced multiple diverging ring-down artifacts from a single source with increasing width and decreasing intensity. Overlap of the diverging artifacts was conspicuous when the focal point was in the far field. Increased width and reduced intensity of acoustic shadowing artifacts was observed with spatial compound imaging. Edge shadowing was eliminated, or reduced. Diverging edge shadowing from the source of the artifact with reduced intensity was detected when the focal point was in the near field. There was no apparent difference of the acoustic enhancement artifact with spatial compound imaging. There was absence or reduction of clutter seen in the urinary bladder when using spatial compound imaging. The appearance of artifacts with spatial compound imaging is slightly different from those with conventional ultrasound imaging.

A miniature pinscher-cross was evaluated for chronic coughing. Computed tomography and bronchoscopy revealed severe, diffuse, cylindrical bronchiectasis secondary to eosinophilic bronchopneumopathy. Computed tomography is the gold standard for diagnosis of bronchiectasis in humans, and should be further investigated in dogs as a means of characterizing severity and pattern of disease.

A 9-year-old neutered female Pug with a 2-week history of pancreatitis was presented for dyspnea, icterus, and intractable vomiting. Sonographically, the gallbladder, intrahepatic bile ducts, and common bile duct were distended. The pancreas was hypoechoic with hyperechoic peripancreatic fat. A mildly heterogeneous intramural mass was present in the muscularis layer of the descending duodenum. A presumptive diagnosis of pancreatitis and smooth muscle tumor of the duodenum leading to common bile duct obstruction was made. The dog died despite supportive care. Necropsy examination confirmed the presence of pancreatitis and an intramural duodenal hematoma.

Postmortem radiographic examinations of animals are often performed in judicial investigation to rule out gunshot and fractures due to cruelty or illegal hunting or poaching activities. Literature describing postmortem changes seen on radiographs of animals is rarely available. Serial abdominal radiography of 6 recently euthanized dogs were performed in an interval of 8h at a tropical ambient temperature of 22-33 degrees C. Severe decomposition of the cadavers prevented the study to be performed beyond 24h. Gradual increment of gas accumulation in the gastrointestinal tract, liver, spleen, kidney and blood vessels were observed. Increased amount of gas in the gastrointestinal tract was detected as early as 8h post-euthanasia and continuously increased throughout the study. Gas was seen in the portal vein and caudal vena cava of all cadavers at 16h post-euthanasia. The presence of gas in the aorta occurred at a later stage. Tubular branching gas pattern in the liver and spleen was first observed and progressed to vesicular gas pattern due to tissue decomposition. This study showed that abdominal radiographic postmortem changes occurred most rapidly between 8 and 16h post-euthanasia at the ambient temperature of 22-33 degrees C.

Postmortem radiographic examinations of animals are often performed in judicial investigation to rule out gunshot and fractures due to cruelty. Literature describing postmortem changes seen on radiographs of animals is rarely available. Serial thoracic radiography of six recently euthanized dogs was performed in an interval of 8 h at a tropical ambient temperature of 22-33 degrees C. Severe decomposition of the cadavers prevented the study to be performed beyond 24 h. Gradual increment of gas accumulation in the pleural cavity, mediastinum, esophagus, blood vessels, cardiac chambers and subcutaneous tissue was observed. Lung changes observed were typical of alveolar pattern and subsequently collapsed secondary to severe pneumothorax. Vacuum phenomenon of the scapulohumeral joints which was not documented in humans was seen in four cadavers. Most radiographic changes were detected at 16 h post-euthanasia. Severe subcutaneous emphysema developed between 16 and 24 h post-euthanasia. This study showed that rapid postmortem changes which could be detected radiographically occur within 24 h of death at the ambient temperature of 22-33 degrees C.

An adult male Aldabra tortoise (Geochelone gigantea) presented with a deep flaking area of the carapace, and histologic examination of biopsies from this area revealed phaeohyphomycosis of the superficial keratinized layers. The disease progressed rapidly and spread to numerous sites on the carapace. After several weeks of regular debridement, deep bone involvement was evident and was confirmed through histologic examination. Fungal culture was attempted but was unsuccessful at isolating the infectious agent. Polymerase chain reaction analysis of extracted DNA from the fixed tissue block identified the fungus as Exophiala oligosperma. Initial treatment included weekly debridement and oral and topical antifungal agents. A nuclear scintigraphy bone scan was performed to determine the extent and status of the infection. Multiple foci of uptake of the radiopharmaceutical marker were present within the carapace, indicating active lesions. The tortoise was maintained on oral antifungal treatment, and lesions resolved over several months. A repeat bone scan performed 1 yr after initial presentation showed reduction in marker uptake, indicating a response to treatment in the deeper lesions. Phaeohyphomycosis should be considered as a differential diagnosis for cases of shell lesions in chelonians.

A previous study showed that a gastric intramural radiolucent band seen on radiographs and a gastric intramural hypoattenuating layer seen on computed tomography were due to the presence of gastric submucosal fat in a cat. There is no known prevalence and distribution pattern of this gastric submucosal fat in cats. This study was carried out to determine the prevalence and distribution pattern of submucosal fat in cat stomachs. Histologic examination of 41 cat stomachs was performed after scheduled killing of cats, obtained from animal shelters. The results revealed that submucosal fat was present in all stomachs. However, thickness and distribution pattern of the submucosal fat varied.

An aged mongrel dog was admitted for hemimandibulectomy as treatment for a mandibular mass that had been diagnosed as osteosarcoma. The fibro-osseous mass that surrounded the first molar tooth and replaced alveolar and cortical bone was reclassified as ossifying fibroma on the basis of anatomic location and histologic features. The tumor was composed of isomorphic fusiform cells with few mitotic figures. Tumoral stroma contained trabeculae of woven bone that were bordered by a single layer of osteoblasts. Excision was deemed complete with no evidence of extension or metastasis by computed tomography of the skull or thoracic and abdominal radiography. The dog was reportedly healthy 6 months after initial presentation. Though far less common than osteosarcoma as a primary canine bone tumor, ossifying fibroma should be included in the differential diagnosis for fibro-osseous proliferations, especially those of the jaw. Although benign, en bloc excision may be necessary for surgical cure.

Postmortem radiographic examinations of animals are commonly performed in judicial investigations to rule out gunshot and fractures. However, there was no available data on radiographic postmortem changes of animals. Forty-one sets of abdominal radiographs of feline cadavers made within 12 h of death were evaluated for postmortem changes. Intravascular gas was detected in 11 of 41 (27%) cadavers. The most common site of intravascular gas was the liver. Intravascular gas was also present in the aorta, femoral artery, celiac and cranial mesenteric arteries, and caudal superficial epigastric artery. Intrasplenic gas was detected in two cadavers. Only two cadavers had distended small intestine. One cadaver had pneumatosis coli. The changes detected were most likely due to putrefaction.

Hybrid tilapias (Oreochromis niloticus x O. mossambicus) were studied to determine gastric emptying and gastrointestinal transit time. The fish were divided into two groups. All fish were fasted for 12 h. The first experiment consisted of 11 fish fed with commercial food pellets and then administration of barium sulfate directly into the stomach using a blunt-end needle. Fish were then radiographed at different time intervals. The second experiment consisted of eight fish, which were given only barium sulfate after 12 h of fasting. In the first experiment, the stomach emptied completely, ranging from 4 to 15h postcontrast medium administration, whereas the gastrointestinal transit time ranged between 10 and 26 h. As for the second experiment, the contrast medium was still retained in the stomach in 50% of the fish after 24 h. The study did not proceed beyond 24 h as fish were considered stressed after this period of time. Thus, no data for the gastrointestinal transit time was obtained.

Smooth muscle origin neoplasia of the urinary bladder wall is rare in dogs. This report describes the ultrasonographic features of two bladder wall leiomyomas and one bladder wall leiomyosarcoma. All three dogs had a single, smoothly marginated, round, hypo to mixed echogenicity intraluminal mass in the urinary bladder. Based on color Doppler examination of the masses, there was no visible blood flow.

An intramural radiolucent band in the stomach wall can be seen on abdominal radiographs of cats without concurrent clinical gastrointestinal signs. A retrospective study of cats with normal abdominal radiographs and computed tomography (CT) was performed to determine the prevalence of this finding. This gastric radiolucent band was seen in 13 of 37 (35%) radiographs. There was no relationship between age, weight and relative obesity and the presence of this radiolucent band. Using CT, an intramural hypoattenuating layer was detected in the stomach wall of four of 15 (27%) cats. The intramural radiolucent band was visible on the radiographs in all four of those cats. This radiographic and CT finding was histologically determined to be normal fat in the gastric submucosa in one cat cadaver.

The clinical, radiological and pathologic features of a biphasic synovial sarcoma in the left elbow joint of a two-year-old male Rottweiler are presented. The tumor showed positive immunoreactivity for vimentin, Epithelial Membrane Antigen (EMA), p53 and PCNA, while it was negative for the cytokeratin used, S-100, Rb and p21. Immunohistochemistry for EMA allowed the identification of epithelioid components of synovial sarcoma, and may, therefore, contribute in establishing a diagnosis of biphasic synovial sarcoma. Intratumoral variation in PCNA immunoreactivity was minimal, indicating that the various tumor components proliferate at more or less similar rates. Overall, the characterized immunohistochemical profile for canine synovial sarcoma, not defined previously, may provide clues to the histogenesis of the phenotypically mesenchymal and epithelial elements of the tumor, and may be of value in the differential diagnosis of challenging cases, decreasing the risk of under- and mis-diagnosis. Although more cases need to be studied to determine whether there is a consistent pattern of immunostaining in canine synovial sarcoma, its potential significance is discussed in relation to the histogenesis, molecular pathology and differential diagnosis of canine synovial sarcoma.

This paper describes a novel method using maximum entropy principle introduced by Shannon to construct a unique integrated character and gives a comparison between this method and multivariate statistics in quantitative genetics. In multivariate genetic analysis multivariate statistics is usually used for a polygenic system of multiple quantitative traits to form several complex character. Genetic analysis can be implemented through treating these correlated elementary traits by using the technique of principal component analysis or canonical correlation. Differing from the multivariate statistics, this paper presents a new method using maximum-entropy principle to obtain a unique integrated character from a set of correlated quantitative traits. This method has the advantages of simple mathematical structure and process, simple and clear results.