Biomedical subjects

John S Mattoon

Publications and source records attributed to John S Mattoon.

At least 19 recordsLinked to original sources

PubMed2006

Nanoparticles as image enhancing agents for ultrasonography.

Nanoparticles have drawn great attention as targeted imaging and/or therapeutic agents. The small size of the nanoparticles allows them to target cells that are beyond capillary vasculature, such as cancer cells. We investigated the effect of solid nanoparticles for enhancing ultrasonic grey scale images in tissue phantoms and mouse livers in vivo. Silica nanospheres (100 nm) were dispersed in agarose at 1-2.5% mass concentration and imaged by a high-resolution ultrasound imaging system (transducer centre frequency: 30 MHz). Polystyrene particles of different sizes (500-3000 nm) and concentrations (0.13-0.75% mass) were similarly dispersed in agarose and imaged. Mice were injected intravenously with nanoparticle suspensions in saline. B-mode images of the livers were acquired at different time points after particle injection. An automated computer program was used to quantify the grey scale changes. Ultrasonic reflections were observed from nanoparticle suspensions in agarose gels. The image brightness, i.e., mean grey scale level, increased with particle size and concentration. The mean grey scale of mouse livers also increased following particle administration. These results indicated that it is feasible to use solid nanoparticles as contrast enhancing agents for ultrasonic imaging.

Animals↗

PubMed2006

Use of helical computed tomography for measurement of thyroid glands in clinically normal cats.

OBJECTIVE: To determine the dimensions and volume of thyroid tissue in clinically normal cats by use of computed tomography. ANIMALS: 8 cats. PROCEDURE: Helical computed tomography images (2-mm collimation) were acquired from the cranial aspect of the second cervical vertebra through the caudal aspect of the fourth cervical vertebra. Data were acquired before contrast medium administration (n = 7 cats) and immediately after contrast medium enhancement (1 cat). Length, width, and height measurements of each thyroid lobe were made by use of transverse, dorsal, and sagittal plane images. Thyroid lobe volume was estimated by use of 3 methods. RESULTS: All thyroid lobes were histologically normal. Mean dimensions for a thyroid lobe were 16.5 x 2.00 x 4.31 mm (length x width x height) using only data from transverse images. Mean thyroid lobar volume was 113.75 mm(3) using the sum of areas method. Mean total volume of thyroid tissue was 215.25 mm(3) using the sum of areas method. CONCLUSIONS AND CLINICAL RELEVANCE: Results may be useful for computed tomography evaluation of abnormal thyroid glands in cats, which warrants investigation.

Animals↗

PubMed2005

Binding of ciprofloxacin labelled with technetium Tc 99m versus 99mTc-pertechnetate to a live and killed equine isolate of Escherichia coil.

This paper describes a simple methodology for evaluating the bacterial binding of ciprofloxacin labelled with technetium Tc 99m. Using this methodology, the binding of 99mTc-ciprofloxacin by live Escherichia coli was compared with the binding of 99mTc-ciprofloxacin by killed E. coli and the binding of 99mTc-pertechnetate (99mTcO4-) by live E. coli. The antimicrobial effect of 99mTc-ciprofloxacin on E. coli was evaluated. Four groups were defined: live E. coli with 99mTc-ciprofloxacin, live E. coli with 99mTcO4 , killed E. coli with 99mTc-ciprofloxacin, and killed E. coli with 99mTcO4-. After 0, 2, and 4 h of incubation of 1 x 10(8) colony-forming units of E. coli suspended in 5 mL of sterile distilled water with 1.85 MBq of 99mTc-ciprofloxacin or 99mTcO4, 1 mL from each sample was centrifuged. The radioactivity of the bacterial pellet and that of the supernatant were measured separately, and the percentage of sample radioactivity attributable to bacterial binding was calculated. Of the 99mTc-ciprofloxacin, 3.6% to 5.9% was bound to live or killed E. coli; only 0.1% to 0.2% of the 99mTcO4- was bound to live E. coli (P < 0.0001). No significant difference in 99mTc-ciprofloxacin binding was found between live and killed E. coli (P = 0.887). An antimicrobial effect on E. coli was seen with 99mTc-ciprofloxacin: colony counts were reduced after 4 h. The small amount of 99mTc-ciprofloxacin binding and the lack of difference in binding between live and killed E. coli may limit the utility of this methodology in evaluating the presence of E. coli infection.

Animals↗

PubMed2004

Correlation of helical and incremental high-resolution thin-section computed tomographic and histomorphometric quantitative evaluation of an acute inflammatory response of lungs in dogs.

OBJECTIVE: To compare quantitative densitometric computed tomography (CT), morphometric, and histologic data of normal lungs in dogs with similar parameters obtained after induction of an acute inflammatory response and determine whether CT densitometry correlated with histopathologic changes. ANIMALS: 6 healthy adult dogs. PROCEDURE: After initial CT, 1 mL of 0.1 M hydrochloric acid (HCI) and 3 mL of autologous blood were instilled into the right middle (RM) and caudal segment of the left cranial (LCCd) lung lobes, respectively. Immediately and 24 hours after instillation, CT was repeated. At 24 hours, dogs were euthanatized and lungs were fixed and sampled for morphometric and histologic evaluation. The CT data were compared with lung morphology and morphometry by use of unpaired t tests. Comparison with lungs from control dogs was performed using Spearman rank correlation coefficients. RESULT: Mean Hounsfield units (HU) from control and baseline HU from experimental dogs were identical. Immediately after instillation of HCI or blood, there was increased attenuation in both lobes. Autologous blood initially induced severe changes that almost completely resolved at 24 hours; HCI induced severe changes at 24 hours. Significant increases in percentage of parenchymal airspace and alveolar diameter resulted in decreased surface area-to-volume ratio in lobes receiving HCl. Histologic scores were significantly higher in the RM lobe, compared with controls. CONCLUSIONS AND CLINICAL RELEVANCE: Computed tomography attenuation correlated well with histomorphometry and histologic findings in this model. Lung lesions after autologous blood were transient and of limited severity. Lesions induced by HCl were severe; alterations in morphometric and histologic parameters were reflected in CT attenuation measurements.

Acute-Phase Reaction↗

PubMed2004

Pulsed-wave Doppler ultrasonographic evaluation of hepatic veins during variable hemodynamic states in healthy anesthetized dogs.

OBJECTIVES: To quantify direction and velocity of blood flow in hepatic veins in dogs under different hemodynamic conditions by use of pulsed-wave Doppler ultrasonography. ANIMALS: 10 healthy dogs. PROCEDURE: Dogs were anesthetized, and venous flow velocities in the quadrate lobe were measured. Arterial blood pressure, right atrial pressure, pulmonary artery pressure, and cardiac output were measured simultaneously. The timing of each waveform during the cardiac cycle was used to identify velocity profiles. Peak waveform velocities were measured during conditions of light anesthesia with isoflurane (baseline; period 1), cardiovascular depression following administration of high-dose isoflurane and esmolol i.v. (period 2), cardiovascular depression with crystalloid volume expansion (period 3), and high cardiac output induced with dobutamine (period 4). Hemodynamic measurements and maximum waveform velocities were compared among the 4 periods by use of an ANOVA and univariate and multivariate linear regression. RESULTS: During each study period, 4 distinct, low-velocity waves were identified. Mean velocities recorded during period 1 were as follows: retrograde atrial contraction a-wave, 7.3 cm/s; antegrade systolic S-wave, 15.0 cm/s; retrograde venous return v-wave, 2.7 cm/s; and antegrade diastolic D-wave, 11.4 cm/s. Mean S:D ratio was 1.27. During periods 3 and 4, S-wave velocity increased; D-wave velocity was highest during period 4. CONCLUSIONS AND CLINICAL RELEVANCE: Consistent hepatic venous velocity profiles were observed in healthy dogs under different hemodynamic conditions. These findings provide baseline values that may be useful in evaluating clinical cases, but further study involving healthy, awake dogs and dogs with cardiac and hepatic diseases is required.

Animals↗

PubMed2003

Evaluation of transurethral cystoscopy and excretory urography for diagnosis of ectopic ureters in female dogs: 25 cases (1992-2000).

OBJECTIVE: To evaluate transurethral cystoscopy and excretory urography for diagnosis of ectopic ureter in female dogs and identify concurrent urogenital abnormalities. DESIGN: Retrospective study. ANIMALS: 25 female dogs. PROCEDURE: Medical records of female dogs that underwent transurethral cystoscopy, excretory urography, and ventral cystotomy were reviewed for signalment, history, physical examination findings, results of bacteriologic culture of urine, and surgical findings. Videotapes of transurethral cystoscopy and radiographic studies were reviewed systematically without knowledge of surgical findings. RESULTS: Ectopic ureters were diagnosed in 24 of 25 (96%) of the dogs, bilaterally in 22 of 24 (91.6%) dogs. Cystoscopic evaluation yielded a correct diagnosis in all dogs when results of ventral cystotomy were used as the diagnostic standard. Cystoscopic evaluation identified a terminal ureteral opening for all ureters. Urethral fenestrations, troughs, striping, and tenting were identified. Abnormalities of the vestibule were identified in all examinations available for review (24/25). The paramesonephric septal remnant and its association with ectopic ureters were identified and characterized by cystoscopy. Radiographic findings were discordant with surgical findings and correctly identified 36 of 46 (78.2%) ectopic ureters and 2 of 4 normal ureters. Hydroureter and renal abnormalities were associated with distal urethral ectopic ureters on radiographic evaluations. CONCLUSIONS AND CLINICAL RELEVANCE: Transurethral cystoscopy was accurate and minimally invasive for identification and classification of ectopic ureters in dogs. Contrast radiography had limitations in diagnosis of ectopic ureters. Cystoscopic findings and associated vaginal and vestibular abnormalities support abnormal embryologic development in the pathogenesis of ectopic ureters.

Animals↗

PubMed2003

Improved detection of metastases on magnetic resonance images by digital tissue recognition: validation using VX-2 tumor in the rabbit.

PURPOSE: To evaluate the ability of a prototype digital tissue recognition (DTR) system to improve the accuracy of detection of metastases on magnetic resonance (MR) images in the rabbit VX-2 tumor model. MATERIALS AND METHODS: Multiple MR imaging (MRI) sequences, including pre-contrast and post-contrast enhanced T1-weighted, T2-weighted, proton-density, and fast short inversion time inversion recovery (FSTIR), were acquired for six rabbits implanted with VX-2 adenocarcinoma. For each rabbit, DTR used the MR intensity characteristics of a known tumor site to highlight other areas suspicious for tumor. Three independent veterinary radiologists with extensive experience in animal MRI interpreted the images for tumor both without and with the results of DTR. The conventional and DTR-assisted interpretations were compared to pathology. RESULTS: Using DTR, the radiologists found an average of 13.2% more true positive sites with a 10.3% reduction in false positives compared to unassisted interpretation. The improvement for the radiologists was statistically significant (McNemar's test, P = 0.0004). The agreement between radiologists using DTR was consistently higher than for their conventional interpretations (kappa statistic). CONCLUSION: Compared with conventional interpretation of MR images, the use of DTR provided a statistically significant improvement in the accuracy of locating more and smaller sites of tumor. This improvement was achieved without the benefit of post-contrast images.

Adenocarcinoma↗

PubMed2003

Determination of extrarenal plasma clearance and hepatic uptake of technetium-99m-mercaptoacetyltriglycine in cats.

OBJECTIVE: To determine maximum extrarenal plasma clearance of technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3) and maximum extrarenal hepatic uptake of 99mTc-MAG3 in cats. ANIMALS: 6 clinically normal adult cats. PROCEDURES: Simultaneously, baseline plasma clearance and camera-based uptake of 99mTc-MAG3 were determined in anesthetized cats. Double exponential curves were fitted to plasma clearance data. Injected dose was divided by area under the curve and body weight to determine 99mTc-MAG3 clearance. Regions of interest were drawn around kidneys and liver, and percentage dose uptake was determined 1 to 3 minutes after injection. After bilateral nephrectomy, simultaneous extrarenal plasma clearance and camera-based hepatic uptake of 99mTc-MAG3 were evaluated in each cat. RESULTS: Mean +/- SD baseline plasma clearance and extrarenal clearance were 5.29 +/- 0.77 and 0.84 +/- 0.47 mL/min/kg, respectively. Mean extrarenal clearance (as a percentage of baseline plasma clearance) was 16.06 +/- 7.64%. For right, left, and both kidneys, mean percentage dose uptake was 9.42 +/- 2.58, 9.37 +/- 0.86, and 18.79 +/- 2.47%, respectively. Mean hepatic percentage dose uptake before and after nephrectomy was 12.95 +/- 0.93 and 21.47 +/- 2.00%, respectively. Mean percentage change of hepatic uptake after nephrectomy was 166.89 +/- 23.19%. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, extrarenal clearance of 99mTc-MAG3 is higher than that of other species; therefore, 99mTc-MAG3 is not useful for estimation of renal function in felids. Evaluation of renal function in cats may be more accurate via camera-based versus plasma clearance-based methods because camera-based studies can discriminate specific organs.

Animals↗

PubMed2003

Correlation of helical and incremental high-resolution thin-section computed tomographic imaging with histomorphometric quantitative evaluation of lungs in dogs.

OBJECTIVE: To develop protocols for helical computed tomography (CT) and axial high-resolution CT (HRCT) of lungs and correlate densitometric CT values with morphometric and histologic data for normal pulmonary tissue in dogs. ANIMALS: 8 healthy adult dogs. PROCEDURE: 2 dogs were used to establish a protocol for helical CT and HRCT of lungs. Six dogs were used to acquire densitometric CT data regarding normal lungs. After the dogs were euthanatized, their lungs were fixed and sampled for morphometric and histologic evaluation. Four CT acquisitions were compared by means of paired t tests. RESULTS: For normal lung tissue of dogs, mean densitometric CT value obtained during helical CT scans reconstructed in a sharp algorithm was -846 Hounsfield units. Values obtained via helical CT or HRCT acquisitions and reconstructed with sharp or standard algorithms did not differ significantly. Morphometric analysis was used to determine the proportion of lung parenchymal (82%) and non-parenchymal tissue (18%). Alveolar size, estimated by mean linear intercept, was approximately 172 microm, and alveolar surface area-to-volume ratio was 0.024 to 0.026 microm(-1). Histologic evaluation confirmed the presence of normal lung tissue. CONCLUSIONS AND CLINICAL RELEVANCE: Correlation of densitometric CT data with morphometric and histologic findings and the establishment of helical CT and HRCT protocols were attained; clinical use of this information may facilitate investigation of pulmonary disease in dogs. Sharp helical CT acquisitions were preferred because of better lung parenchyma detail and rapid image acquisitions, compared with HRCT.

Animals↗

PubMedDate not supplied

The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: an in vitro study.

OBJECTIVES: To compare centered versus distal tibial plateau leveling osteotomy (TPLO) position on cranial tibial subluxation, postoperative tibial plateau angle (TPA), and tibial long axis shift (TLAS). STUDY DESIGN: In vitro biomechanical evaluation. ANIMALS: Six pairs of canine cadaveric hind limbs. METHODS: One limb of each pair was randomly assigned to the distal (TPLO-D) or centered (TPLO-C) osteotomy group. Cranial tibial subluxation (CTS) under load was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transection, and after TPLO; a corrected CTS value was also calculated. Postoperative TPA and TLAS were measured. Comparisons were made using 1-way repeated measures ANOVA with a Tukey's multiple comparison post hoc test for CTS, and a Wilcoxon's sign rank test for TPA and TLAS. Significance was set at P<.05. RESULTS: TPLO-C had a significantly lower mean CTS than TPLO-D (P<.01). Corrected CTS was also significantly lower in TPLO-C than in TPLO-D (P<.001). Postoperative TPA and TLAS were less in TPLO-C than in TPLO-D (P=.0312). CONCLUSION: Our results confirm that distal centering of the TPLO leads to craniodistal translation of the tibial plateau, TLAS, and a postoperative TPA that is greater than expected. This geometric effect has the biomechanical effect expected of inadequate tibial plateau leveling, namely incomplete neutralization of cranial tibial thrust. CLINICAL RELEVANCE: The centered osteotomy position is geometrically more precise, and biomechanically more effective than the distal position.

Analysis of Variance↗

PubMedDate not supplied

Combined use of ultrasonography and contrast enhanced computed tomography to evaluate acute necrotizing pancreatitis in two dogs.

The imaging findings in two miniature schnauzers with acute necrotizing pancreatitis are described. Both dogs were treated previously for diabetes mellitus and hyperlipidemia. Vomiting, anorexia, and lethargy were observed in both dogs at presentation. Laboratory evaluations supportive of pancreatitis included left shift, abnormally high serum amylase and lipase activities, hypocalcemia, and abnormally high serum activities of liver enzymes. Sonographically, both dogs had diffusely enlarged hypoechoic pancreatic tissue with anechoic foci compatible with necrosis, abscessation, phlegmon, and pseudocysts formation. Contrast-enhanced computed tomography (CT) findings in both dogs were compatible with pancreatic necrosis. Dog 1 was managed medically for 11 days. Follow-up CT scan in this dog disclosed decreased pancreatic size and increased contrast enhancement compatible with partial resolution of pancreatitis.

Animals↗

PubMedDate not supplied

Computed tomographic densitometry of normal feline thyroid glands.

We studied the computed tomographic (CT) appearance and determined Hounsfield units (HU) for normal thyroid tissue in eight cats. Helical CT images (2 mm collimation) were acquired from cranial aspect of the second cervical vertebra (C2) through caudal aspect of the fourth cervical vertebra (C4). Data were acquired before contrast medium administration (n = 7), after delayed contrast medium enhancement (n = 8), and immediately after contrast medium enhancement after a second dose of contrast medium (n = 8). Attenuation of thyroid tissue was compared with surrounding tissues. Before contrast medium enhancement, thyroid tissue was hyperattenuating to the surrounding soft tissues. After delayed contrast medium enhancement, thyroid tissue was hyperattenuating to surrounding soft tissues and isoattenuating to contrast medium-laden blood vessels. Immediately after contrast medium enhancement, thyroid tissue was hyperattenuating to surrounding soft tissues and hypoattenuating to contrast medium-laden blood vessels. The thyroid glands were dorsolateral to the trachea, ovoid, and displayed homogenous contrast medium enhancement. Circular regions of interest were drawn on the right and left thyroid lobes. Densitometric data of thyroid tissue were as follows: precontrast medium enhancement, 123.2 HU (95% CI: 119.4-127.1 HU); delayed contrast medium enhancement, 132.1 HU (95% CI: 127.4-136.8 HU); immediate postcontrast medium enhancement, 168.5 HU (95% CI: 163-173.9 HU). Normal feline thyroid tissue is easily detected using CT without contrast medium enhancement. This information may be useful for CT evaluation of abnormal feline thyroid glands.

Animals↗

PubMedDate not supplied

Technique for equine cervical articular process joint injection.

Degenerative changes and osteochondrosis of articular processes are common sources of stiffness or pain in the equine cervical spine. Temporary relief of the clinical signs related to these maladies may be achieved by injecting corticosteroids into the joint. This is routinely done by ultrasound-guided needle placement. The cervical articular processes and joint form an easily identifiable sonographic landmark, a step-like echogenic surface described as having the appearance of a "chair."

Animals↗

PubMedDate not supplied

Comparison between malignant and nonmalignant splenic masses in dogs using contrast-enhanced computed tomography.

The ability of computed tomography (CT) to distinguish malignant from nonmalignant splenic masses was evaluated in 21 dogs with 24 masses. CT scans of the abdomen were performed pre- and postintravenous contrast medium administration before splenectomy or euthanasia. Splenic masses were evaluated objectively based on Hounsfield units (HU) and volume. Subjective criteria included location within the spleen (head, body, or tail), margination, homogeneity, and attenuation compared to the remaining splenic parenchyma. Characteristics of malignant and nonmalignant masses were compared. The nonmalignant masses were divided into splenic hematomas and nodular hyperplasia for further analysis. Fourteen (58.3%) of the masses were nonmalignant; 10 (41.7%) were malignant. Malignant splenic masses had significantly lower attenuation values, measured in HU, than nonmalignant splenic masses, on both pre- and postcontrast images (P<0.05). On postcontrast images, there was a significant difference in attenuation characteristics among all three subsets of splenic masses (malignant, hematoma, hyperplasia), with nodular hyperplasia having the highest HU values (90.3), hematomas having intermediate HU values (62.5), and malignant splenic masses having the lowest HU values (40.1). A receiver operator characteristic curve of postcontrast medium HU values revealed 55 as the best threshold value to distinguish malignant from nonmalignant masses, with those less than the threshold value being malignant. Abdominal CT is a useful diagnostic imaging modality for evaluation of focal canine splenic masses, with a significant difference in imaging characteristics between malignant and nonmalignant masses.

Animals↗

PubMedDate not supplied

(99M)Tc-ciprofloxacin in imaging of clinical infections in camelids and a goat.

(99M)Tc-ciprofloxacin was used to image five adult camelids and a juvenile goat with clinical and/or radiographic signs of infection. (99m)Tc-ciprofloxacin (range 10-33 MBq/kg) was injected intravenously and a series of 2-min static images were acquired at 1- and 4-h postinjection. At 24-h postinjection, 5-min static images were acquired. Only the skull or abdomen was imaged in the adults; the whole body was imaged in the goat. The quality of the 1-, 4-, and 24-h studies was evaluated subjectively. Normal and abnormal areas of (99m)Tc-ciprofloxacin uptake were recorded and subjectively graded as mild, moderate or intense. Image quality was best 4-h postinjection. Twenty-four-hour images were poor because of insufficient radioactivity. (99m)Tc-ciprofloxacin imaging resulted in true positive or true negative scans in four of six animals. Two false-negative studies occurred. Intense (99m)Tc-cirofloxacin activity was seen in the lungs and urinary bladder, moderate/intense activity in the kidneys, and mild activity in the physes/epiphyses, liver and intermittently in the gastrointestinal tract. The normal distribution of (99m)Tc-ciprofloxacin in camelids/small ruminants differed from people. Further studies to determine the sensitivity and specificity of infection detection using (99m)Tc-ciprofloxacin in animals are warranted.

Animals↗

PubMedDate not supplied

Polypoid cystitis in 17 dogs (1978-2001).

Polypoid cystitis is a rare disease of the urinary bladder in dogs characterized by inflammation, epithelial proliferation, and development of a polypoid mass or masses without histopathologic evidence of neoplasia. Medical records of 17 dogs with polypoid cystitis were reviewed to determine the clinical and laboratory features of this disorder and to assess treatment and outcome. Most affected dogs (15/17) were female and presented for evaluation of hematuria or recurrent urinary tract infection (UTI). Proteus spp were the most common bacterial isolates (12/52 or 23.1%) identified when all urine samples obtained for culture at any time during the course study were considered. Other commonly isolated organisms included Escherichia coli , Staphylococcus spp, and Enterococcus spp. Several dogs (7/17) also had cystic calculi at some time during the course of their disease. Most of the masses (11/14) were located cranioventrally in the bladder as opposed to transitional cell carcinoma, which has a predilection for the bladder neck or trigone area. It is unknown whether persistent or recurrent UTI predisposes to polyp formation or if polyps predispose to UTI. Surgery and removal of all polyps was the most efficacious treatment in dogs of this study. The question of whether or not polyps represent preneoplastic lesions remains unanswered and constitutes an area for future investigation.

Animals↗

PubMedDate not supplied

Four-legged broiler chicken with two cloacae and three ceca.

This case report examines an Arbor Acres female x Peterson male crossbred 6-wk-old female broiler chicken with four legs, two cloacae, and three ceca. The intestines occupied the caudodorsal portion of the abdominal cavity with three ceca attached to the terminal end of the ileum. The left lateral cecum was larger and had a divided distal end that terminated into 2-cm-long blind sacs. The rectum was dilated and divided into two cloacae that each opened on the dorsolateral aspect of both the right and left cloacal elevator muscles. The two extra legs were attached to the pygostyle by cartilage and skin tissue. Both femoral heads of the extraneous legs were fused together. The extra legs were smaller in size (approximately 17 cm in length) compared with the normal legs (approximately 22 cm). The femoral heads of the two normal legs were disarticulated from the acetabulum.

Animals↗

PubMedDate not supplied

Digital fluoroscopic excretory urography, digital fluoroscopic urethrography, helical computed tomography, and cystoscopy in 24 dogs with suspected ureteral ectopia.

The purpose of this study was to determine the diagnostic utility of helical computed tomography (CT) for the diagnosis of ectopic ureters in the dog and to compare these findings with those of digital fluoroscopic excretory urography and digital fluoroscopic urethrography. Ureteral ectopia was confirmed or disproved based on findings from cystoscopy and exploratory surgery or postmortem examination. Of 24 dogs (20 female, 4 male) evaluated, 17 had ureteral ectopia. Digital fluoroscopic excretory urography and CT correctly identified ureteral ectopic status and site of ureteral ectopia (P < .05). Urethrography did not reliably detect ureteral ectopia. No false-positive diagnoses of ureteral ectopia were made in any of the imaging studies. Cystoscopic findings significantly agreed with findings during surgery in determining ureteral ectopic status and ectopic ureter site. One false-positive cystoscopic diagnosis of unilateral ureteral ectopia was made in a male dog. Kappa statistics showed better agreement between CT and both cystoscopy and surgical or postmortem examination findings with regard to presence and site of ureteral ectopia compared with other imaging techniques. CT was more useful than other established diagnostic imaging techniques for diagnosing canine ureteral ectopia.

Animals↗