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E R Wisner

Publications and source records attributed to E R Wisner.

At least 37 records · Page 2Linked to original sources
PubMed1995

Indirect computed tomography lymphography using iodinated nanoparticles: time and dose response in normal canine lymph nodes.

RATIONALE AND OBJECTIVES: We evaluated the effect of time and dose on lymph node iodine uptake after subcutaneous or submucosal administration of iodinated nanoparticles used for computed tomography lymphography. METHODS: We injected 0.1-6 ml of a 15% wt/vol iodinated nanoparticle suspension into the distal extremities subcutaneously (n = 5) or into the buccal submucosa (n = 7) of normal dogs. Precontrast and 4, 12, 24, and 48 hr after contrast administration, CT scans of opacified lymph nodes were obtained. Iodine concentration, node volume, and total iodine uptake were estimated for each node. RESULTS: All estimated parameters increased between 4 and 12 hr postcontrast (p < .05), with no significant increase thereafter. At 24 hr postcontrast, iodine concentration ranged from 0.01 to 16.1 mg/ml (47-568 Hounsfield units). The average iodine concentration and total iodine uptake increased with contrast dose (p < .05) for all lymph node groups evaluated. Node opacification also revealed internal architectural detail. CONCLUSION: Subcutaneous and submucosal injections of iodinated nanoparticles result in a dose-dependent iodine uptake in targeted lymph nodes. In addition, architectural detail within opacified nodes can be visualized.

Animals↗
PubMed1995

Needle aspiration lung biopsy: reevaluation of the blood patch technique in an equine model.

PURPOSE: To reexamine the blood patch technique in a laboratory model of lung biopsy free of confounding clinical variables. MATERIALS AND METHODS: An equine model of lung biopsy was developed with an excised lobe connected to an insufflation bulb and pressure monitor. Patched and control unpatched punctures were made in the lung surface, and the pressure within the lung was raised to the maximum achievable. Whether air leakage from the puncture sites could be induced was determined and, if so, at what pressure it occurred. RESULTS: At statistical analysis with the Kaplan-Meier test and the Cox proportional hazards regression model, the difference between failure of the patched and unpatched punctures was statistically significant (P < .0001). CONCLUSION: The blood patch technique is effective in the laboratory setting and deserves reevaluation in a clinical series with updated biopsy techniques.

Animals↗
PubMed1995

Morphologic and morphometric characterization of lung collagen content in clinically normal adult thoroughbreds in race training.

Interstitial and bronchointerstitial pulmonary patterns are commonly observed in thoracic radiographs of Thoroughbreds. Prominent interstitial and bronchointerstitial pulmonary patterns are observed in clinically normal horses, and in horses with respiratory tract disease. Until recently, the relevance of these pulmonary patterns was not known. Previous studies indicated that bronchiolitis, bronchiolar epithelial hyperplasia, epithelial metaplasia, and bronchial arteriolar recruitment correlated strongly with the prominence of the interstitial and bronchointerstitial pulmonary patterns observed radiographically. We examined the content and distribution of collagen in the lungs of 7 clinically normal Thoroughbreds in race training. After standardized fixation, lung tissue was treated with a compound that selectively stains collagen. Standard morphometric techniques were used to determine the volume density of parenchymal tissue and parenchymal airspace, mean linear intercept (estimate of alveolar size), alveolar surface area-to-volume ratio, percentage of parenchyma composed of collagen, percentage of airway wall composed of collagen, and airway wall thickness. These values were compared with radiographic and histopathologic scores obtained from the same horses. The volume density of parenchymal tissue and small airway wall thickness correlated strongly with the prominence of the bronchial and bronchointerstitial pulmonary patterns observed radiographically. Small airway thickness was also highly correlated with the perceived prominence of the interstitial pulmonary patterns observed radiographically, and morphometric estimates of parenchymal tissue and parenchymal collagen. There were also strong correlations between the volume density of parenchymal tissue, the percentage of parenchymal collagen, peribronchiolar mononuclear cell infiltrates, and bronchiolar mucosal plication estimates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Iodinated nanoparticles for indirect computed tomography lymphography of the craniocervical and thoracic lymph nodes in normal dogs.

RATIONALE AND OBJECTIVES: We evaluated the imaging characteristics of an interstitially or intraperitoneally delivered iodinated particulate contrast agent for computed tomography (CT) lymphography of the craniocervical and thoracic lymph nodes. METHODS: We injected 2-4 ml of 15% wt/vol iodinated nanoparticle suspension subcutaneously, submucosally, or intraperitoneally in eight normal dogs. CT and plain radiographic images were obtained prior to contrast administration and 4 hr, 24 hr, and 7 days after injection. Correlation was made to detailed postmortem assessment. RESULTS: CT images showed enhancement of regional nodes draining injection sites. Mean attenuation of opacified nodes was 313 +/- 297 (mean +/- standard deviation), 536 +/- 453, and 492 +/- 372 Hounsfield units at 4 hr, 24 hr, and 7 days postinjection, respectively. Lymph node opacification on CT images correlated well with node location found at postmortem. CONCLUSION: Craniocervical and thoracic lymph nodes can be effectively opacified from interstitial or intraperitoneal delivery of this iodinated nanoparticulate contrast agent.

Animals↗
PubMed1993

Radiographic and microscopic correlation of diffuse interstitial and bronchointerstitial pulmonary patterns in the caudodorsal lung of adult thoroughbred horses in race training.

Complete thoracic radiographic examinations were performed on 7 horses ranging in age from 24 to 60 months, followed by in-situ lung fixation. Radiographs were examined by 3 radiologists for the presence, degree and distribution of generalised pulmonary patterns within a region of interest in the caudodorsal lung. Pulmonary tissue was obtained from 12 sites within a designated volume of interest in the caudodorsal lung, corresponding to the area of interest evaluated radiographically, and examined for the presence, character and severity of microscopic lesions. Radiographic findings within the volume of interest consisted of mild to moderate bronchial, bronchointerstitial, or interstitial pulmonary patterns. Interstitial and bronchointerstitial radiographic findings were related to severity of peribronchiolar mononuclear cell infiltrates, the degree of bronchiolar mucosal plication, and alveolar capillary and peribronchial blood vessel erythrocyte content. The severity of the interstitial radiographic pattern was inversely associated with the perceived diagnostic quality of the radiographic examinations. There was no evidence of spatial variation in the severity of the microscopic changes examined in this limited pulmonary region. Inter-rater reliability between radiologists was good in the assessment of diagnostic quality of the radiographic examinations but poor in assessing severity of the primary generalised pulmonary patterns within the radiographic region of interest.

Animals↗
PubMed1991

Osteomyelitis of the axial border of the proximal sesamoid bones in seven horses.

Destructive lesions of the axial region of the proximal sesamoid bones were identified by radiography in eight fetlocks and seven lame adult horses. Lameness ranged from 2 to 5 (mean 4; scale 1 to 5) at the time of examination, with a duration of 10 days to two years (mean 5.6 months). Destructive lesions involved both proximal sesamoid bones when examined radiographically and were situated primarily at the level of the mid-body and apical region of the axial borders. Some lesions were cystic, whereas others eroded the axial border more diffusely. Scintigraphy revealed markedly increased activity within the proximal sesamoid bones of the clinically lame limb of four of the five horses examined. In four horses, post mortem computed tomography revealed axial border bone destruction and cavitary lesions within cancellous bone of affected proximal sesamoid bones. Lesions seen by computed tomography were larger than those identified on radiographic examination. Cavitary lesions not seen radiographically were identified in the proximal sesamoid bones of two clinically unaffected fetlocks examined for comparison in two of the seven horses. Evidence of acute, subacute or chronic/reparative osteomyelitis of the axial region of the proximal sesamoid bones was seen in the 10 fetlocks identified as abnormal from radiography or computed tomography. Also, three horses had septic synovitis of the flexor sheath of the clinically affected limb; of these, two had septic arthritis of the fetlock joint.

Animals↗
PubMedDate not supplied

Ureteral obstruction after ureteroneocystostomy in dogs assessed by technetium TC 99m diethylenetriamine pentaacetic acid (DTPA) scintigraphy.

OBJECTIVE: To use technetium Tc 99m diethylenetriamine pentaacetic acid (99mTc-DTPA) renal scintigraphy to monitor ureteral obstruction after ureteroneocystostomy in a canine model of partial ureteral obstruction. STUDY DESIGN: Experimental study. ANIMALS: Eight normal adult dogs. METHODS: Partial ureteral obstruction was created in 8 dogs by incomplete ligation of the terminal right ureter. Two weeks later, ureteroneocystostomy was performed in 7 dogs with unilateral partial ureteral obstruction and in 1 dog that had developed bilateral partial ureteral obstruction. 99mTc-DTPA scintigraphy was performed intermittently for 2 weeks after ureteroneocystostomy. Renal transit time of each kidney, as assessed by the time to maximal uptake (time of peak), and glomerular filtration rate, as assessed by percentage of kidney uptake of the radiopharmaceutical between 1 and 3 minutes, were estimated. Comparison between affected and nonaffected kidneys was performed with the Wilcoxon rank sum test. RESULTS: Unilateral partial ureteral obstruction was induced successfully in 7 dogs. In 1 dog, bilateral partial obstruction was induced inadvertently. After ureteroneocystostomy, percentage of kidney uptake of 99mTc-DTPA was low in 4 affected kidneys. The uptake returned to within normal limits in 2 of the kidneys during the observation period. The time activity curve had a more rounded appearance or was increasing continuously for all affected kidneys. A significant increase in renal transit time was observed 2 and 4 days after ureteroneocystostomy. Transit time progressively returned to normal by 4 to 11 days for all affected kidneys except 1. CONCLUSION: Ureteroneocystostomy resulted in persistent partial ureteral obstruction for 4 to 11 days as determined by 99mTc-DTPA scintigraphy. CLINICAL RELEVANCE: 99mTc-DTPA scintigraphy may be a useful procedure for monitoring renal function and ureteral obstruction after ureteroneocystostomy. Persistent partial ureteral obstruction may be seen 1 to 2 weeks after ureteral reimplantation in dogs with previously existing dilated ureters.

Animals↗
PubMedDate not supplied

Evaluation of risk factors for luxation after total hip replacement in dogs.

OBJECTIVE: To identify risk factors for luxation after canine total hip replacement (THR). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: 256 client-owned dogs that underwent THR. METHODS: Patient data surveyed included signalment, body weight, diagnosis, prior hip surgery, implant size, intraoperative complications, and angle of lateral opening of the acetabular component. RESULTS: Postoperative complications were recorded in 20 cases (7.8%). The most common complication was dorsal luxation which occurred in 12 dogs (4.7%). The interval between joint replacement and luxation ranged from 1 to 116 days (mean, 44 days). In 1 case, luxation was attributable to failure of the repair of an intraoperative fracture of the greater trochanter. Excluding this case, the mean angle of lateral opening in those dogs that sustained luxation was 62 degrees (range, 46 degrees - 75 degrees). The mean angle of lateral opening overall was 48 degrees (range, 18 degrees - 76 degrees). The angle of lateral opening was the only factor that had a statistically significant effect on whether luxation occurred (P = .035). Acetabular revision, performed primarily to reduce the angle of lateral opening, was performed in 8 dogs and successfully prevented subsequent luxation. CONCLUSION: Luxation of the prosthesis is substantially under the control of the surgeon. It is recommended that the acetabular cup be inserted at an angle of lateral opening of 35 degrees to 45 degrees. In those cases of THR luxation in which an inappropriate angle of lateral opening is identified, acetabular revision arthroplasty generally results in a good clinical outcome.

Acetabulum↗
PubMedDate not supplied

Radiographic evaluation of acetabular component position in dogs.

OBJECTIVE: To assess the usefulness of standard radiographic projections for determining acetabular cup position and to compare 2 radiographic methods for calculation of the angle of lateral opening of the acetabular cup. STUDY DESIGN: In vitro radiographic study. METHODS: Acetabular components were mounted on a custom-built inclinometer. The effect of varying the angles of lateral opening, inclination, version, and centering of the x-ray beam on the radiographic appearance of the cup was investigated. The angle of lateral opening was calculated trigonometrically after direct measurement and by means of computer-aided image analysis. RESULTS: Using a ventrodorsal radiograph, the computer-aided measurement of angle of lateral opening was accurate to within 5 degrees when the true angle of lateral opening was > or = 40 degrees. In the case of direct measurement, the calculated angle was accurate to within 5 degrees only when the true angle was > or = 60 degrees. An increasing angle of inclination was associated with reduced accuracy of calculation of the angles of lateral opening and version. Standard radiographic assessment of acetabular version and inclination was not found to be clinically useful. The displacement of the x-ray beam, which would cause significant error in the determination of lateral opening, is unlikely to be exceeded in practice. Cup size had no significant effect on the accuracy of the results. CONCLUSIONS: Computer-aided image analysis can be used to calculate angles of lateral opening to within 10 degrees throughout the range of acetabular positions seen in practice and is appropriate for postoperative documentation of cup position. The angles of inclination and version should be interpreted with caution.

Acetabulum↗
PubMedDate not supplied

Arabinogalactan-coated superparamagnetic iron oxide: effect of particle size in liver MRI.

OBJECTIVE: We evaluated the effect of particle size on MR contrast-enhancing properties of arabinogalactan-coated superparamagnetic iron oxide (AG-SPIO) in tumor-bearing rats. MATERIALS AND METHODS: T2*-weighted gradient-recalled echo MR studies were performed on rats with surgically implanted liver tumors before and after AG-SPIO administration. Contrast-to-noise ratio (CNR) and percent contrast enhancement (PCE) were calculated for animals given small (15.7 +/- 9.5 nm: n = 6), medium (49.1 +/- 19.7 nm; n = 4), and large (86.9 +/- 27.5 nm; n = 4) particles intravenously (10 mumol Fe/kg). RESULTS: Postcontrast CNRs were 15.8 +/- 6.9, 8.9 +/- 4.1, and 10.0 +/- 1.8 for small, medium, and large particle groups, respectively. The PCE was -60.0 +/- 3.3, -75.5 +/- 7.9, and -80.5 +/- 1.2%. There was a significant difference in preversus postcontrast CNR for all particle sizes (p < 0.001) and in PCE for small particles as compared with the two larger sizes (p < 0.001). There was no between-group statistical difference in postcontrast CNR for any particle size. CONCLUSION: Larger AG-SPIO particles slightly improve liver contrast enhancement, but have no significant effect on hepatic lesion detection as assessed by CNR.

Animals↗
PubMedDate not supplied

Osteochondrosis of the lateral trochlear ridge of the talus in seven Rottweiler dogs.

Eleven lesions of osteochondrosis in the lateral trochlear ridge of the talus were diagnosed in seven young Rottweiler dogs. Diagnosis was based on clinical and radiographic evaluations. Defects in the lateral trochlear ridge and osteochondral fragments arising from the dorsal and proximal margins of the ridge were visible radiographically. The dorsal 45 degrees lateral-plantaromedial oblique (D45 degrees L-P1MO) projection was the most useful in identifying the lesions. Exploratory arthrotomies were performed in six affected tarsi. In three cases, histologic examination revealed mineralized osteochondral fragments consistent with a diagnosis of osteochondrosis.

Animals↗
PubMedDate not supplied

High-resolution parathyroid sonography.

The purpose of this study was to assess the diagnostic utility of parathyroid ultrasonography to differentiate causes of hypercalcemia in dogs. We analyzed qualitative and quantitative ultrasound imaging findings and clinical pathology data from 33 dogs that underwent parathyroid ultrasound examination as part of the diagnostic evaluation for hypercalcemia. Diagnoses of the diseases causing hypercalcemia included parathyroid carcinoma (n = 5), parathyroid adenoma (n = 15), parathyroid adenomatous hyperplasia (n = 6), chronic renal insufficiency (n = 3), and hypercalcemia of malignancy (n = 4). All parathyroid lesions were round or oval and hypoechoic compared with surrounding thyroid parenchyma. Adenomatous and adenocarcinomatous glands were 4 mm or larger in longest linear measurement on US examination and were statistically significantly larger than hyperplastic glands. (p < 0.001) Linear measurements of parathyroid glands acquired at the time of ultrasound examination correlated well with direct size determination after surgical excision. (r2 = 0.9, p < 0.0001) Parathyroid lesions > or = 4 mm are highly suspicious for parathyroid adenoma or carcinoma, while US lesions < 4 mm most likely represent primary adenomatous hyperplasia or secondary parathyroid hyperplasia. Parathyroid size estimation from ultrasound examination is an accurate predictor of true size.

Animals↗
PubMedDate not supplied

Ultrasonographic evaluation of renal size in dogs with acute allograft rejection.

The purpose of this study was to determine the best method to ultrasonographically monitor renal size changes associated with acute allograft rejection in dogs. Qualitative changes in renal cortical and medullary echogenicity were also evaluated, although this was not a major focus of the study. Four unrelated, mixed-breed dogs underwent bilateral nephrectomies and heterotopic renal allograft transplantation. Ultrasound examinations of transplanted kidneys were initiated at 3 days after surgery and continued at 2-3 day intervals until death (38 +/- 2 days). Ultrasound measurements of kidney length, width, height, cross-sectional area, and estimated volume were used to assess relative changes in renal size associated with transplantation and rejection. Transplanted kidneys had a rapid increase in volume and cross-sectional area that averaged 103% and 83% above baseline levels, respectively, by 17 days after transplantation. The increased size was attributed to a combination of hypertrophy and acute rejection, the latter of which was confirmed at postmortem. Kidney volume decreased to approximately 35% above baseline volume by day 34 as rejection became more advanced. Qualitative changes associated with rejection included medullary enlargement with decreased echogenicity early in the study, followed by increased cortical thickness and echogenicity with poor cortical medullary definition in the latter stages of the survival period. It was concluded that relative changes in renal allograft size can be easily monitored with ultrasound. In regard to linear measurements, changes in renal width were more pronounced than changes in height or length with acute rejection. Therefore measurements that incorporate the width, namely volume or cross-sectional area, appear to be the most sensitive for monitoring changes in allograft size. Renal cross-sectional area measurements are preferred because they are simple to perform using the automated calculation capability of most newer ultrasound units.

Acute Disease↗
PubMedDate not supplied

Quantitative methods for indirect CT lymphography.

In this investigation, we applied quantitative CT methods to characterize contrast enhanced lymph nodes opacified using iodinated contrast media for indirect CT lymphography. Iodinated nanoparticles were injected into the buccal submucosa and SQ into the metatarsus and metacarpus of four normal swine (1.0-4.0 ml/site, 76 mg I/ml). Attenuation (HU), volume (cm3), iodine concentration (mg I/cm3), total iodine uptake (mg I), contrast-to-noise ratio (CNR), and percent injected dose (%ID) were estimated in opacified inguinal, cervical and parotid/mandibular lymph nodes using manual image segmentation techniques on 24 hour post-contrast CT images. Lymph node volumes estimated by multiple slice ROI analysis were compared with estimates obtained by post-excisional weight measurements. HU and iodine concentration increased 5-20 fold in opacified nodes (p < 0.01) and CNR increased more than four-fold (p < 0.001). %ID ranged between 3.5 and 11.9% and did not appear dose related. ROI estimated lymph node volumes approximated volumes calculated from weight measurements. (R2 = 0.94, p < 0.0001). We conclude that interstitially injected iodinated nanoparticles increase attenuation and conspicuity of targeted nodes on CT images. Quantitative methods could play an important clinical role in more accurate metastasis detection.

Animals↗
PubMedDate not supplied

Congenital atresia of the parotid duct in a horse.

Congenital anomalies of the equine salivary glands and their ductal systems are rare. In man, parotid duct atresia is thought to be due to a congenital malformation of the first branchial arch. One horse with unilateral parotid salivary duct atresia is described. Imaging modalities available for accurate diagnosis, and treatment options, are reviewed.

Animals↗
PubMedDate not supplied

Renal transit time of 99mTc-diethylenetriaminepentacetic acid (DTPA) in normal dogs.

The transit time of 99mTc-DTPA in the kidneys is an indicator of renal function that has been used in humans for the diagnosis of renal obstruction, renal artery stenosis, and rejection of renal transplants. Its use, however, has not been reported in the dog. 99mTc-DTPA scintigraphy was performed in 8 normal dogs and the time of peak was calculated as the time between the injection and the maximum renal uptake. Deconvolution analysis was performed to estimate the renal retention function using 3 different techniques, i.e. the matrix method, the fast Fourier transform (FFT) method, and the constrained least square method. The parenchymal and whole kidney mean transit times were calculated from the deconvolved renogram using alternatively the thorax and the aorta as the input function. Average mean transit times ranged from 137 to 184 seconds. Parenchymal mean transit time was significantly shorter than whole kidney mean transit time (P<0.03). Mean transit time calculated with the thorax as the input function was significantly longer than mean transit time calculated with the aorta (P<0.001). No differences were observed between mean transit time calculated with the matrix, FFT and constrained least square methods.

Animals↗
PubMedDate not supplied

Non-cardiac thoracic ultrasound in 75 feline and canine patients.

The purpose of this study was to describe the ultrasonographic appearance of non-cardiac diseases of the small animal thorax. Ultrasound images from a total of 75 animals (26 cats and 49 dogs) were compared to cytologic, histopathologic, and necropsy findings. Clinical diagnoses included neoplasia of the mediastinum, pleura, or lungs (43); idiopathic mediastinal cyst (3); diaphragmatic or peritoneopericardial hernia (4); lung lobe torsion (1); pulmonary eosinophilic infiltrates (1); and idiopathic, chylous, congestive heart failure, or lymphangiectasia associated pleural effusion (14). In the remaining 9 patients, a definitive diagnosis was not obtained. Ultrasound-guided fine needle aspirate was performed in 56 patients; 1 of these also had an ultrasound-guided tissue core biopsy. Of the fine needle aspirates, 51 (91%) were diagnostic. Ultrasound examination, particularly when accompanied by guided tissue sampling, can be a valuable tool in the diagnosis of non-cardiac intrathoracic lesions.

Animals↗