What is your diagnosis? Circumferential foreign body within the soft t tissues of the neck and pronounced tracheal compression.
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Airway Obstruction↗
Biomedical subjects
E R Wisner
Publications and source records attributed to E R Wisner.
Transvenous coil embolization of an extrahepatic portosystemic shunt in a dog: a naturally occurring model of portosystemic malformations in humans.
Congenital patent ductus venosus (PDV) occurs far more commonly in dogs than in people; consequently, the natural course of the disease in dogs was studied as a model to understand the pathophysiology behind the vascular anomaly and its response to therapy better. In this report, the authors describe the results of percutaneous coil embolization as a single procedure in a dog with a single congenital extrahepatic portocaval shunt and compare portosystemic vascular anomalies (PSVA) seen in dogs with those seen in children.
Angiography↗
Long-term effect of irradiation on lymph node uptake of interstitially delivered nanoparticulate contrast media.
RATIONALE AND OBJECTIVES: To characterize the long-term effects of therapeutic doses of ionizing radiation on the uptake and distribution of percutaneously delivered particulate contrast media in normal lymph nodes. METHODS: Two milliliters of an iodinated nanoparticle suspension (76 mg I/mL) was injected subcutaneously or submucosally into nine normal adult beagles. Region of interest analysis was used to estimate the volume, attenuation, and iodine concentration of opacified targeted lymph nodes and nonopacifled contralateral nodes on 24-hour postinjection CT images. All lymph nodes were then irradiated with 50 Gy in 25 fractions of 2 Gy/d. Contrast-enhanced quantitative CT was repeated 12 months after irradiation. RESULTS: Contrast-enhanced nodes averaged 2.3+/-0.8 times the volume of nonenhanced contralateral nodes before irradiation. The mean attenuation of contrast-enhanced nodes increased to 305 to 380 Hounsfield units from a pre-enhancement value of approximately 25 Hounsfield units. Opacified node volumes after irradiation averaged 61% to 86% of preirradiation volumes but were generally not statistically different. Contrast uptake assessed by average attenuation and iodine concentration decreased significantly by an average of 17% to 22% after irradiation and was significantly less than preirradiation uptake. Qualitatively, irradiated nodes generally appeared smaller than nonirradiated nodes, but the distribution pattern of contrast media did not appear to be appreciably altered. CONCLUSIONS: Lymph node irradiation resulted in only minimal decreases in contrast media uptake and node volume at 12 months. These effects presumably would not appreciably alter the potential clinical value of indirect lymphography for evaluating patients undergoing radiation therapy.
Animals↗
Lymph node uptake of interstitially delivered particulate contrast media before and after irradiation in dogs.
RATIONALE AND OBJECTIVES: The authors' purpose was to assess the effects of ionizing radiation on the uptake and distribution of interstitially delivered particulate contrast medium in normal lymph nodes in dogs. MATERIALS AND METHODS: Two milliliters of an iodinated nanoparticle suspension (NC 67722 Sterile Suspension, 76 mg of iodine per milliliter) was injected subcutaneously or submucosally into nine normal adult beagle dogs. Targeted lymph node groups were evaluated with computed tomography (CT). Region-of-interest analysis was used to estimate volume, attenuation, and iodine concentration of the opacified nodes and nonopacified contralateral nodes on CT images obtained before and 24 hours after the injection. All right-sided and some left-sided lymph nodes were irradiated with 50 Gy in 25 fractions of 2 Gy per day, beginning 28-35 days after the CT examination. Contrast medium administration and quantitative CT imaging were performed again 3 months after irradiation. RESULTS: Contrast material uptake resulted in a twofold increase in node volume before irradiation (P < .0001). Mean attenuation of contrast-enhanced nodes increased to 230-330 HU from a precontrast enhancement value of 36.5 HU. After irradiation, opacified node volumes decreased to approximately 25%-50% of their preirradiation volumes (P < .02). Contrast material uptake decreased 10%-15% after irradiation but was not significantly less than preirradiation uptake. Qualitatively, no substantial difference in contrast material distribution existed between irradiated and nonirradiated nodes. CONCLUSION: An elective irradiation dose decreased lymph node size, but the imaging characteristics of opacification were not otherwise appreciably altered 3 months after irradiation.
Analysis of Variance↗
A multiple detector array helical x-ray microtomography system for specimen imaging.
An x-ray computed microtomography system for specimen and small animal imaging was built and tested. The system used seventeen 48-microm-wide detector arrays (a charge coupled device camera) and helical acquisition techniques. Images were acquired using 540 rays/view and 400 views/2pi. The modulation transfer function (MTF) of the computed tomography images demonstrated 50 microm limiting resolution, with MTF > 10% for objects larger than 60 microm (approximately 8.3 cycles/mm). While soft tissue discrimination was compromised by a low signal-to-noise ratio, equine medullary bone core samples and the murine skeleton were well visualized. The incorporation of multiple detector arrays provided a 17-fold improvement in x-ray efficiency, which is a very important step toward improving the potential of microtomography as a scientific tool.
Algorithms↗
Effect of partial ureteral obstruction on results of renal scintigraphy in dogs.
OBJECTIVE: To use scintigraphy to determine the effects of partial ureteral obstruction on renal transit time and induction of diuresis in dogs. ANIMALS: 8 adult dogs. PROCEDURE: Scintigraphy was performed, using technetium Tc 99m diethylenetriaminepentacetic acid (Tc 99m-DTPA), before and within 2 weeks after surgical induction of unilateral partial ureteral obstruction. Time of peak (TOP) for the parenchyma (pTOP) and whole kidney (wTOP) and mean-transit time (MTT) for the parenchyma (pMTT) and whole kidney (wMTT) were determined by evaluation of renal time-activity curves before and after deconvolution analysis. Percentage uptake for each kidney between 1 and 3 minutes after injection of Tc 99m-DTPA was determined and used to indicate glomerular filtration rate. The effect of diuresis was determined by measuring the slope of decrease in activity after i.v. administration of furosemide. Obstruction was documented by direct inspection of the ureter. RESULTS: There was a concomitant increase in pTOP, wTOP, pMTT, and wMTT of the kidney with the partially obstructed ureter in all dogs at various times between 2 and 9 days after surgery. Concurrently, renal time-activity curves changed shape. Percentage renal uptake of the affected kidney was decreased in 2 dogs. Response to furosemide injection was inconsistent for kidneys before surgery and for kidneys with obstructed and nonobstructed ureters after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Scintigraphy may be a useful procedure for the evaluation of renal function in dogs with ureteral obstruction. Induction of diuresis appears to be of little value for differentiating renal function in dogs with obstructed and nonobstructed ureters.
Animals↗
Ultrasonography of the thyroid and parathyroid glands.
High-resolution thyroid and parathyroid ultrasonography can play an integral part in the diagnosis and management of patients with clinically undifferentiated cervical masses, thyroid carcinomas or adenomas, and primary parathyroid hyperplasia or neoplasia. Because the study is inexpensive, noninvasive, and easily performed, ultrasonography can be performed as a screening test early in the evaluation of a patient, and ultrasound findings can corroborate the results of other diagnostic procedures, leading to a more accurate diagnosis.
Adenoma↗
Contrast-enhancement properties of irradiated normal lymph nodes: initial experience with interstitially delivered iodinated nanoparticles.
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Animals↗
A modular lymphographic magnetic resonance imaging contrast agent: contrast enhancement with DNA transfection potential.
A gadolinium-chelated liposomal contrast agent has been prepared, and magnetic resonance imaging (MRI) efficacy has been examined by indirect magnetic resonance lymphography. A lipidic N,N'-dimethylethylenediamine derivative (4) containing a 10,12-diyne-diacyl domain was treated with DTPA anhydride followed by GdCl3 complexation. The complex was confirmed using MALDI spectrometry. An equimolar mixture of the Gd-chelate lipid and a commercially available diyne-PE was formulated as a liposome suspension and irradiated with UV light prior to imaging experiments. Subcutaneous injection of the liposomal gadolinium agent and subsequent MRI of rabbit axillary and popliteal lymph nodes revealed significant contrast enhancement up to 4 h postinjection. To explore the possibility of imaging a DNA transfection event, the gadolinium contrast mixture was formulated with the cationic transfection lipid DOTAP and complexed with the reporter gene encoding luciferase. DNA transfection studies on the NIH3T3 cell line confirmed the transfection activity of the dual-purpose contrast agent and exemplified the potential toward development of an imaging and DNA delivery vehicle.
3T3 Cells↗
Comparison of results of hormonal analysis of samples obtained from selected venous sites versus cervical ultrasonography for localizing parathyroid masses in dogs.
OBJECTIVE: To compare a technique in which samples obtained from selected venous sites are analyzed for parathyroid hormone (PTH) concentration versus usefulness of cervical ultrasonography for localizing primary hyperparathyroidism (PHP) in dogs. DESIGN: Prospective study. ANIMALS: 12 dogs with PHP. PROCEDURE: For each dog, blood samples were collected from the left and right jugular veins and 1 cephalic vein for determination of serum PTH concentration. Ultrasonography of the neck was performed in each dog. Each dog underwent exploratory surgery of the neck. Abnormal appearing parathyroid tissue was removed. Dogs were included in the study if serum calcium concentration decreased within 12 hours after surgery, hypercalcemia completely resolved within 96 hours after surgery, and serum calcium concentration was maintained within the reference range for at least 6 months after surgery. RESULTS: Serum PTH concentrations from the 3 veins were similar in 11 of 12 dogs with PHP. In 1 dog, the serum PTH concentration from the jugular vein ipsilateral to a parathyroid adenoma was greater than that from the contralateral jugular or cephalic vein. Ultrasonography correctly identified a parathyroid mass and its location in 10 of 11 dogs with a solitary abnormal parathyroid gland and in 1 dog in which both parathyroid glands were enlarged. CLINICAL IMPLICATIONS: Surgeons may benefit from knowing the location of abnormal parathyroid tissue in dogs with PHP before surgical exploration. Ultrasonography has potential value for identifying and localizing abnormal parathyroid tissue, whereas sample collection from selected sites for PTH analysis is not likely to be helpful.
Adenocarcinoma↗
Sentinel node imaging via a nonparticulate receptor-binding radiotracer.
UNLABELLED: Technetium-99m-labeled polydiethylenetriamine pentaacetic acid polymannosyl polylysine (DTPA-man-PL) was synthesized and tested for lymph node scintigraphy by subcutaneous administration. The agent was designed for receptor-mediated uptake by mannosebinding protein, which resides on the plasma membrane of reticuloendothelial cells. METHODS: Subcutaneous injections of a 99mTc-labeled agent having 18 DTPA and 82 mannosyl groups attached to a polylysine of 100 units ([99mTc]DTPA18-man82-PL100) were made at the level of the metacarpus and metatarsus of three healthy rabbits. Images were acquired at 1, 6, 12 and 24 hr. Popliteal and axillary nodes were then assayed for percent of injected dose (%ID). A negative control study was performed in three normal rabbits with [99mTc]DTPA18-PL100. RESULTS: Significant differences in mean 24-hr %ID between the receptor specific and nonspecific agents were observed for both the popliteal (p < 0.006) and axillary (p < 0.012) nodes. Popliteal percent injected dose at 24 hr was 3.00 +/- 0.72% for [99mTc]DTPA-man-PL and 0.13 +/- 0.08% for [99mTc] DTPA-polylysine. Axillary accumulation at 24 hr was 2.84 +/- 0.83% for [99mTc]DTPA-mannosyl-polylysine and 0.22 +/- 0.12% for [99mTc] DTPA-polylysine. Percent injected dose of the receptor-specific agent was highest (4%) during the 6-hr scan. Accumulation of the nonspecific agent by the popliteal and axillary nodes at 6-hr postinjection was approximately 0.5%. CONCLUSION: This study provides proof of principle for lymphoscintigraphy by receptor-mediated delivery of a nonparticulate imaging agent.
Animals↗
Indirect computed tomography lymphography using iodinated nanoparticles to detect cancerous lymph nodes in a cutaneous melanoma model.
RATIONALE AND OBJECTIVES: To evaluate differences in contrast uptake in normal and cancerous lymph nodes on indirect computed tomography (CT) in swine, we conducted lymphographic examinations after subcutaneous injection of a lymphotropic iodinated nanoparticle suspension. METHODS: Perilesional subcutaneous contrast injections (2 ml per lesion) of a 15% wt/vol iodinated nanoparticle suspension were made in immature Sinclair miniature swine (n = 5) with cutaneous melanomas. Average attenuation, iodine concentration, node volume, and total iodine uptake were estimated on the CT scans for each opacified lymph node 24 hr after injection. Nodes were classified as normal or cancerous microscopically, and the percentage of tumor replacement was estimated in cancerous nodes. RESULTS: Average attenuation and iodine concentration were higher in normal nodes, and total iodine uptake was higher in cancerous nodes with greater than 25% replacement (p < .05). Architectural alterations in opacified cancerous nodes included medullary filling defects, expansile cortical lesions, and disruption of corticomedullary junctions. CONCLUSION: Quantitative and qualitative differences in iodinated nanoparticle enhancement characteristics are useful in distinguishing between normal and cancerous lymph nodes on indirect CT lymphography examinations.
Animals↗
Characterization of normal and cancerous lymph nodes on indirect computed tomography lymphographic studies after interstitial injection of iodinated nanoparticles.
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Animals↗
Preclinical evaluation of manganese carbonate particles for magnetic resonance imaging of the liver.
RATIONALE AND OBJECTIVES: We characterized the physical, biological, and imaging properties of a manganese (Mn) carbonate particle suspension, a contrast agent for hepatic magnetic resonance (MR) imaging. METHODS: Mn carbonate suspensions were produced by controlled precipitation and characterized using light microscopy, transmission electron microscopy, and in vitro relaxivity studies. Efficacy of the agent was studied in normal and tumor-bearing rats using T1-weighted MR imaging. RESULTS: Following intravenous injection of Mn carbonate particles at doses ranging from 10 to 100 mumol Mn/kg, peak hepatic contrast enhancement of approximately 35% occurred from about 125 min until the termination of the MR imaging studies that varied from 125 to 305 min. Lesion conspicuity was increased because of relative intensity differences between normal liver and tumor. Data also showed that Mn carbonate particles dissolved on delivery to the liver, allowing Mn to interact with intrahepatic macromolecular complexes to provide positive contrast enhancement. CONCLUSION: Mn carbonate particles produce significant and sustained hepatic enhancement and should improve detection of small or isointense liver lesions.
Analysis of Variance↗
Indirect computed tomography lymphography of subdiaphragmatic lymph nodes using iodinated nanoparticles in normal dogs.
RATIONALE AND OBJECTIVES: We evaluated the imaging characteristics of an iodinated particulate contrast agent for indirect computed tomography (CT) lymphography of normal subdiaphragmatic lymph nodes in dogs. METHODS: Four milliliters of a 15% (wt/vol) iodinated nanoparticle suspension was injected into the gastric, colonic, rectal, or cervical submucosa, loose paraprostatic fascia, or metatarsal subcutaneous tissues in 10 healthy beagles. Endoscopic, CT, or ultrasound guidance was used when necessary to facilitate contrast agent delivery. CT and radiographic images were obtained prior to contrast administration and at 4 hr, 24 hr, and 7 days postcontrast injection. Postmortem examinations were then conducted. RESULTS: CT images showed enhancement of regional lymph nodes draining the various injection sites. The mean attenuation of opacified nodes was 678 +/- 463 Hounsfield units 24 hr after injection and remained elevated 7 days later. Lymph node opacification on CT images correlated well with the node location observed on postmortem examinations. CONCLUSION: Subdiaphragmatic lymph nodes can be effectively opacified using an iodinated nanoparticle contrast agent for indirect CT lymphography.
Abdomen↗
A molecular receptor-binding contrast agent for magnetic resonance imaging of the liver.
RATIONALE AND OBJECTIVES: A gadolinium complex of polydiethylenetriamine pentaacetic acid polyneogalactosyl polylysine (Gd-DTPA-gal-PL) was developed and tested as a paramagnetic contrast agent for magnetic resonance (MR) imaging of the liver. The agent was designed for receptor-mediated uptake by the asialoglycoprotein receptor (ASGP-R), which is unique to hepatocytes and exhibits high specificity for galactose-terminated glycoconjugates. METHODS: Polylysine was alkylated with a mixed anhydride of diethylenetriamine pentaacetic acid. This product was complexed with gadolinium and N-alkylated with 3-oxopropyl-1-thio-beta-D-galactopyranoside. With this reaction sequence, we prepared a gadolinium complex consisting of 2284 galactose groups and 858 chelators per polylysine having 2136 amino groups. Hepatic enhancement was tested by MR imaging of nine rats with liver-implanted mammary adenocarcinoma before and after injection of 20 x 10(-9) mol/kg Gd-DTPA858-gal2284-PL2136. The conjugate was labeled with technetium-99m and tested (1.5 x 10(-10) mol/kg) for hepatic specificity via nuclear imaging. RESULTS: Mean hepatic enhancement was 86% within 10 min and remained constant for 25 min. Hepatic relative intensity exceeded preinjection intensities by at least four times the standard deviation of the preinjection values (p < .01). The tumors, which are devoid of ASGP-R, did not exhibit significant enhancement (p > .1). The liver accumulated 90% of the technetium-99m-labeled conjugate. CONCLUSION: A molecular paramagnetic ligand to the asialoglycoprotein receptor has been developed for hepatocyte-specific MR contrast enhancement.
Adenocarcinoma↗
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↗
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↗