Epidural myelolipoma in a Silken Windhound.

A 12-year-old female spayed, Silken Windhound dog was presented with a 3-month history of lethargy and cervical and lumbosacral spinal pain. No significant abnormalities were noted on CBC or serum biochemical assays. Magnetic resonance imaging of the spine demonstrated a soft tissue mass within the ventral and right epidural space at the level of the L7 vertebra. During surgery, a pale brown mass was identified within the epidural fat. Cytologic and histopathologic examinations demonstrated that the mass was composed of adipose tissue and hematopoietic elements, consistent with a myelolipoma. The lumbosacral spinal pain resolved after surgery. Epidural myelolipomas are rarely reported in the human and veterinary literature.

Evaluation of bronchial narrowing in coughing dogs with heart murmurs using computed tomography.

BACKGROUND: The origin of cough in dogs with heart murmurs is controversial, because the cough could be primary cardiac (eg, pulmonary edema, bronchi compression by left-sided cardiomegaly) or respiratory (eg, bronchomalacia, other bronchial or bronchiolar disease, interstitial lung disease) in origin. HYPOTHESIS/OBJECTIVES: To study the association between left atrium (LA) dilatation and cardiomegaly and bronchial narrowing in coughing dogs with heart murmurs using computed tomography (CT). ANIMALS: Twenty-one client-owned coughing dogs with heart murmurs and 14 historical control dogs. METHODS: Dogs with cough and murmur were prospectively recruited over 4 months. Cervical and thoracic radiography, echocardiography, and thoracic CT were performed in enrolled dogs. Control dogs, with no disease on thoracic CT and no records of heart murmur and coughing, were gathered from the institution's computerized database. Degree of bronchial narrowing was assessed using the bronchial-to-aorta (Ao) ratio, measured by 3 radiologists blinded to the clinical findings. After identifying bronchi that were significantly narrowed in dogs with murmur compared to controls, the relationship between degree of narrowing and LA/Ao ratio (measured echocardiographically) and vertebral heart scale (VHS) measured radiographically was studied in dogs with murmur using mixed-effects regression. RESULT: Significant narrowing was identified for all left-sided bronchi and the right principal, middle, and caudal bronchi in the coughing dogs, compared with controls. Increasing LA size and VHS were significantly inversely associated with diameter for all left-sided and right-sided bronchi indicated above. CONCLUSION AND CLINICAL IMPORTANCE: Results indicate an association between LA enlargement and cardiomegaly and bronchial narrowing and support heart size-associated exacerbation of cough in dogs with murmurs.

Kidney and cystic volume imaging for disease presentation and progression in the cat autosomal dominant polycystic kidney disease large animal model.

BACKGROUND: Approximately 30% of Persian cats have a c.10063C > A variant in polycystin 1 (PKD1) homolog causing autosomal dominant polycystic kidney disease (ADPKD). The variant is lethal in utero when in the homozygous state and is the only ADPKD variant known in cats. Affected cats have a wide range of progression and disease severity. However, cats are an overlooked biomedical model and have not been used to test therapeutics and diets that may support human clinical trials. To reinvigorate the cat as a large animal model for ADPKD, the efficacy of imaging modalities was evaluated and estimates of kidney and fractional cystic volumes (FCV) determined. METHODS: Three imaging modalities, ultrasonography, computed tomography (CT), and magnetic resonance imaging examined variation in disease presentation and disease progression in 11 felines with ADPKD. Imaging data was compared to well-known biomarkers for chronic kidney disease and glomerular filtration rate. Total kidney volume, total cystic volume, and FCV were determined for the first time in ADPKD cats. Two cats had follow-up examinations to evaluate progression. RESULTS: FCV measurements were feasible in cats. CT was a rapid and an efficient modality for evaluating therapeutic effects that cause alterations in kidney volume and/or FCV. Biomarkers, including glomerular filtration rate and creatinine, were not predictive for disease progression in feline ADPKD. The wide variation in cystic presentation suggested genetic modifiers likely influence disease progression in cats. All imaging modalities had comparable resolutions to those acquired for humans, and software used for kidney and cystic volume estimates in humans proved useful for cats. CONCLUSIONS: Routine imaging protocols used in veterinary medicine are as robust and efficient for evaluating ADPKD in cats as those used in human medicine. Cats can be identified as fast and slow progressors, thus, could assist with genetic modifier discovery. Software to measure kidney and cystic volume in human ADPKD kidney studies is applicable and efficient in cats. The longer life and larger kidney size span than rodents, similar genetics, disease presentation and progression as humans suggest cats are an efficient biomedical model for evaluation of ADPKD therapeutics.

Comparison of the diagnostic quality of computed tomography images of normal ocular and orbital structures acquired with and without the use of general anesthesia in the cat.

OBJECTIVE: To compare the diagnostic quality of computed tomography (CT) images of normal ocular and orbital structures acquired with and without the use of general anesthesia in the cat. ANIMAL STUDIED: Eleven privately owned cats with nasal disease presenting to a single referral hospital. PROCEDURES: All cats received a complete ophthalmic examination. A 16 multislice helical CT system was utilized to acquire images of the skull and neck with and without the use of general anesthesia. Images were acquired before and after the administration of intravenous iodinated contrast. Images of normal ocular and orbital structures were evaluated via consensus by two board-certified radiologists. Visibility of ocular and orbital structures, degree of motion, and streak artifact were assessed and scored for each image set in the transverse, dorsal, and sagittal planes. RESULTS: The use of general anesthesia did not significantly affect the diagnostic quality of images. No motion artifact was observed in any CT image. Streak artifact was significantly increased in scans performed in the transverse orientation but not in the dorsal orientation or sagittal orientation and did not affect the diagnostic quality of the images. Contrast enhancement did not significantly enhance the visibility of any ocular or orbital structures. CONCLUSION: Diagnostic CT images of normal ocular and orbital structures can be acquired without the use of general anesthesia in the cat.

Computed tomographic features of feline nasopharyngeal polyps.

The computed tomographic (CT) findings of histopathologically confirmed nasopharyngeal polyps are described in 13 cats. Most polyps were mildly hypoattenuating to adjacent muscles and isoattenuating to soft-tissue (n= 13), homogeneous (n = 12) and with ill-defined borders (n = 10) on precontrast images. After contrast medium administration, the polyps were homogeneous (n = 11), with well-defined borders (n = 13), oval (n = 13), and had rim enhancement (n = 13). Nasopharyngeal polyps were pedunculated in 11 cats with a stalk-like structure connecting the polyp through the auditory tube to an affected tympanic bulla. All cats had at least one tympanic bulla severely affected, with CT images identifying: (1) complete (n = 12) or partial (n = 1) obliteration of either the dorsal or ventral compartments with soft-tissue attenuating material; (2) pathologic expansion (n = 13) with wall thickening (n = 10) that was asymmetric in nine cats; and (3) identification of a polyp-associated stalk-like structure (n = 11). Nine cats had unilateral tympanic bulla disease ipsilateral to the polyp, and four cats had bilateral tympanic bulla disease, most severe ipsilateral to the polyp with milder contralateral pathologic changes. Two cats had minimal osteolysis of the tympanic bulla. Enlargement of the medial retropharyngeal lymph node was seen commonly (n = 8), and in all cats it was ipsilateral to the most affected tympanic bulla. One cat had bilateral lymphadenopathy. CT is an excellent imaging tool for the supportive diagnosis of nasopharyngeal polyps in cats. CT findings of a well-defined mass with strong rim enhancement, mass-associated stalk-like structure, and asymmetric tympanic bulla wall thickening with pathologic expansion of the tympanic bullae are highly indicative of an inflammatory polyp.

Detection of pneumothorax and pleural effusion with horizontal beam radiography.

Forty-seven patients with a known history of thoracic trauma or clinical suspicion of pneumothorax were selected for thoracic imaging. The patient population was composed of 42 dogs and five cats. Standard vertical beam (VB) left and right lateral and ventrodorsal/dorsoventral (VD/DV) projections were obtained for each patient, and at least one horizontal beam (HB) projection (VD projection made in lateral recumbency). A total of 240 images were reviewed. Subjective assessment for the presence and degree of pneumothorax and pleural effusion was made more confidently with HB projections. Pneumothorax was identified in at least one projection in 26 patients (26 dogs) and pleural effusion in 21 patients (19 dogs and two cats). Pneumothorax and pleural effusion were present concurrently in 17 dogs. Pneumothorax and pleural effusion were graded for each image as absent, mild, moderate, or severe. Right (P < 0.001) and left (P < 0.05) lateral HB VD projections and the standard VB left lateral projection (P < 0.05) were significantly more likely to detect and grade pneumothorax severely than the VB VD/DV views. The right lateral HB projection had the highest rate of detection and gradation of severity for pneumothorax compared with other views. VD/DV projections had the lowest sensitivity for detection of the pneumothorax and gradation of severity for pneumothorax and pleural effusion. No significant difference in diagnosis (P = 0.9149) and grade (P = 0.7757) of pleural effusion were seen between views, although the left lateral HB had both the highest rate of detection and grade of severity.

The VetMousetrap: a device for computed tomographic imaging of the thorax of awake cats.

The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.

Diagnostic imaging in terrestrial invertebrates: Madagascar hissing cockroach (Gromphadorhina portentosa), desert millipede (Orthoporus sp.), emperor scorpion (Pandinus imperator), Chilean rosehair tarantula (Grammostola spatulata), Mexican fireleg tarantula (Brachypelma boehmei), and Mexican redknee tarantula (Brachypelma smithi).

Limited veterinary information is available for invertebrates. The purpose of this study was to improve baseline knowledge of invertebrate radiology and radiographic anatomy by evaluating diagnostic imaging modalities in six terrestrial invertebrate species. For each species, variably sized individuals were radiographed using multiple techniques to obtain optimal images, and radiographic technique charts were formulated using this data. To evaluate anatomy and compare gastrointestinal transit information among carnivores, omnivores, and herbivores, gastrointestinal contrast radiography was employed. Individuals were fed radiographic contrast media or contrast-containing food items. Contrast radiography resulted in improved visualization of gastrointestinal anatomy in all species. Radiographic contrast media was visualized in gastrointestinal tracts in at least one individual of all taxa for greater than 60 days, substantially longer than expected. Survey and gastrointestinal contrast radiographs of cockroaches were superior to those studies in other species. Zoo Biol 27:109-125, 2008. (c) 2008 Wiley-Liss, Inc.

Quantitative ultrasound, magnetic resonance imaging, and histologic image analysis of hepatic iron accumulation in pigeons (Columbia livia).

Iron overload was induced by iron dextran i.v. in clinically healthy adult pigeons, Columbia livia, (n = 8). Hemosiderosis was induced in all treated birds. Two control pigeons received no iron injections. Pigeons did not show clinical signs of iron overload during the 6-wk study. Ultrasound examination of the liver in the pigeons receiving iron dextran was performed on days 0, 13, 28, and 42. No ultrasound images were collected on the control pigeons. Magnetic resonance imaging was performed on days 0, 13, 28, and 42 on all study pigeons and imaging sequences were collected in three different imaging formats: T1, T2, and gradient-recalled echo (GRE). Surgical liver biopsies were performed on pigeons receiving iron dextran on days 2, 16, and 45 (at necropsy). A single liver sample was collected at necropsy from the control birds. Histologic examination, quantitative image analysis, and tissue iron analysis by thin-layer chromatography were performed on each liver sample and compared to the imaging studies. Although hemosiderosis was confirmed histologically in each experimental pigeon, no significant change in pixel intensity of the ultrasound images was seen at any point in the study. Signal intensity, in all magnetic resonance imaging formats, significantly decreased in a linear fashion as the accumulation of iron increased.

Characterization of lymphomatous lymph nodes in dogs using contrast harmonic and Power Doppler ultrasound.

Doppler ultrasound has been used in humans to determine angioarchitecture of lymph nodes as the criterion for the determination of malignancy. We hypothesized that the vascular and perfusion patterns of a canine malignant lymph node could be characterized with intravenous microbubble ultrasound contrast media and that contrast harmonic ultrasound could provide better conspicuity of the angioarchitecture when compared with Power Doppler ultrasound. In this study, 11 peripheral lymph nodes in dogs with histologically verified malignant lymphoma were imaged with fundamental ultrasound, Power Doppler ultrasound, and three contrast harmonic pulse sequences to characterize the vascular pattern and perfusion. Vascular imaging was greatly enhanced in these nodes with 2.13 times more vessels seen with contrast harmonic ultrasound compared with Power Doppler ultrasound (P < 0.01). The angioarchitecture of lymphomatous lymph nodes of dogs in this study were similar to those previously described in malignant superficial lymph nodes in human patients; 45.5% of the nodes had displacement of the central hilar vessel, 45.5% had aberrant vessels, 63.6% had pericapsular vessels, 36.4% had subcapsular vessels, and 81.8% had loss of the central hyperechoic band in fundamental sonography. Poor perfusion, indicated by a lower mean pixel intensity increase between pre- and postcontrast administration images, was seen in 36.4% of the lymph nodes while 63.6% had fair to good perfusion. The perfusion patterns in nine of the 11 lymph nodes were homogenous and two showed focal hypoperfused regions. We conclude that Power Doppler and contrast harmonic ultrasound are beneficial in accurately depicting angioarchitechture and can provide additional information in determining the presence of malignant vascular characteristics within lymphomatous nodes in dogs.

Use of contrast harmonic ultrasound for the diagnosis of congenital portosystemic shunts in three dogs.

Contrast harmonic ultrasound was used to determine macrovascular and perfusion patterns in three dogs with congenital extrahepatic solitary portosystemic shunts (PSS). With coded harmonic angiographic ultrasound, the size and tortuosity of the hepatic arteries were subjectively increased. Single pulse intermittent low-amplitude harmonic perfusion imaging provided contrast enhancement time-intensity curves from regions of interest in the liver. Mean (+/- standard deviation) peak perfusion times of dogs with PSS were significantly shorter (p = 0.01; 7.0 +/- 2.0 s) than reported in normal dogs (22.8 +/- 6.8 s). The contrast inflow slope for the dogs with PSS (14.6 +/- 3.7 pixel intensity units [PIU] was significantly (p = 0.05) larger than reported for normal dogs (3.6 +/- 1.4 PIU/s). These results indicate that combined coded harmonic angiographic and contrast harmonic perfusion sonography can be used to detect increased hepatic arterial blood flow as an indicator of PSS in dogs.

Tissue harmonic ultrasound for imaging normal abdominal organs in dogs and cats.

Normal cats (n = 38) and dogs (n = 40) were imaged with fundamental ultrasound and tissue harmonic ultrasound. Images of the liver, gall bladder, spleen, left kidney, urinary bladder, and jejunum were collected in all animals. Images of the left adrenal gland were collected in all dogs. All normal cats and dogs had improved imaging with tissue harmonic ultrasound. The number of organs with improved conspicuity ranged from one to all organs imaged. The most common organ to have improved conspicuity was the jejunum (100% of dogs and 89% of cats). Significant improvement by tissue harmonic ultrasound was seen in images of gall bladder (p = .05) and left adrenal gland (p = .02) in dogs, and spleen, urinary bladder, and intestinal images (p = .01) in cats. Significant improvement was seen in tissue harmonic ultrasound images of the gall bladder in dogs weighing greater than 16 kilograms (p = .03) and in the images of the urinary bladder of dogs weighing less than 16 kilograms (p = .02). These data suggest that image quality improvement of normal organs using tissue harmonic ultrasound is consistent but not predictable. The exception was the jejunum, where improvement was seen in all dogs. Sonographers should be cognizant of the potential benefits of tissue harmonic ultrasound.

Ultrasonographic appearance of edema caused by injections in the mammary gland attachments of dairy cows.

OBJECTIVE: To determine the ultrasonographic appearance and detectability of edema induced by SC injection of mild silver protein suspension in the mammary gland attachments of dairy cows. DESIGN: Prospective study. ANIMALS: 6 lactating cows. PROCEDURE: In each cow, the number of quarters that received injections was randomly assigned. A mild silver protein susoension was injected SC into cranial and caudal mammary gland attachment sites. The number of injections and volume injected were determined on the basis of the appearance of the mammary gland and the desired subjective visual effect. Seventeen sites were chosen for injection and 7 sites did not receive injections. Ultrasonographic images were obtained 1 day prior and 6 days after injections were started. Cows received injections 1, 3, and 5 days after initial sonography. The sonographer was unaware of which sites received injections. RESULTS: Ultrasonography revealed alternating hypoechoic and hyperechoic bands at injection sites. Certain injections caused the intimal surface of the subcutaneous abdominal vein to develop a corrugated appearance. All injection sites were correctly identified ultrasonographically (100% sensitivity, 100% specificity) with a positive and negative predictive value of 1.0. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that mild silver protein suspension injected SC to enhance the appearance of the mammary glands of dairy cows can be readily detected by ultrasonography. Detection of injection sites should be made on the basis of the distribution and ultrasonographic appearance of edema.