IMAGING DIAGNOSIS-ULTRASOUND UNCOMMON FEATURES OF AN ABDOMINAL GOSSYPIBOMA IN A DOG.

An abdominal mass was incidentally detected in a 12-year-old, neutered female, crossed breed dog. Abdominal ultrasonographic examination showed a well-delineated, irregular, heterogeneous mass that did not generate any distal acoustic shadowing. Transcutaneous US-guided biopsy of the mass were nonconclusive but raised the possibility of neoplasia. Surgery discovered a mass embedded in the omentum and a large quantity of surgical sponges were identified in cut section. To the authors' knowledge, this represents the first published case of gossypiboma casting no characteristic distal acoustic shadowing.

Imaging diagnosis-paraganglioma of the cauda equina: MR findings.

The magnetic resonance imaging features of a cauda equina paraganglioma in a 5-year-old dog are described. Imaging revealed a well-defined, strongly contrast-enhancing mass invading the adjacent vertebral body and infiltrating the intervertebral foramen bilaterally. Flow void, compatible with increased drainage veins around the mass, and macroscopically visible neovessels in contrast-enhanced magnetic resonance angiography, as reported in numerous human studies, were not visible in this single case. The tumor recurred despite aggressive surgery and radiotherapy. This neoplasm should be considered in the differential diagnosis of cauda equina abnormalities in dogs.

Feasibility for detecting liver metastases in dogs using gadobenate dimeglumine-enhanced magnetic resonance imaging.

Early detection of liver metastases may improve the prognosis for successful treatment in dogs with primary tumors. Hepatobiliary-specific contrast agents have been shown to allow an increase in magnetic resonance imaging (MRI) detection of liver metastases in humans. The purpose of this prospective study was to test the feasibility for using one of these agents, gadobenate dimeglumine, to detect liver metastases in dogs. Ten consecutive dogs known to have a primary tumor were recruited for inclusion in the study. All dogs were scanned using the same protocol that included a T2-weighted respiratory-triggered sequence, T1 VIBE, diffusion-weighted imaging, and 3D-FLASH before and after dynamic injection of gadobenate dimeglumine contrast medium. Delayed imaging was performed less than 30 min after injection and up to 60 min in two cases. Histological analysis of liver lesions identified in delayed phases was performed for each case and confirmed metastatic origin. In all cases, lesion number detected in hepatobiliary contrast-enhanced sequences was statistically higher than in other sequences. Optimal lesion detection occurred with a 3D-FLASH sequence acquired in the transverse plane and less than 30 min after injection. Findings indicated that gabobenate dimeglumine enhanced MRI is a feasible technique for detecting liver metastases in dogs.

Transcatheter glue arterial embolization of a mass in the hind limb of a dog.

This article reports the use of transarterial glue embolization in the treatment of a soft-tissue mass in the hind limb of a dog that was referred for a > 15-cm diameter soft tissue mass in the caudal thigh. Clinical improvement showed that the percutaneous therapeutic cyanoacrylate glue embolization procedure was technically feasible and useful.

Imaging diagnosis--left retrocaval ureter and transposition of the caudal vena cava in a dog.

Retrocaval ureter and transposition of the caudal vena cava are each, rare developmental anomalies. We describe the usefulness of static fluid magnetic resonance urography and dynamic contrast-enhanced magnetic resonance urography in the diagnosis of these anomalies. Basic techniques, benefits, and drawbacks of magnetic resonance urography are presented.

Lung ring-down artifact as a sign of pulmonary alveolar-interstitial disease.

Three dogs with presumptive cardiogenic pulmonary edema underwent a thoracic ultrasonographic examination. Multiple ring-down artifacts involving both sides of the thorax emanating from the pleural-lung interface were detected. When clinical and radiographic signs of pulmonary edema were resolved, ring-down artifacts were not observed. The ring-down artifact may be a useful diagnostic sign for screening the lung of animals with acute respiratory distress where radiographs are not feasible.

Twinkling artifact in small animal color-Doppler sonography.

Twinkling artifact is a recently described color-Doppler phenomenon that has not been studied in the veterinary field. Our purpose was to assess the grade of the artifact in vitro with varying urolith compositions, and to evaluate its potential role in clinical practice. Five canine and feline uroliths types of 100% mineral composition were studied in vitro with color-Doppler sonography, and a prospective study was performed in 41 patients with renal, bladder, gallbladder, or digestive focal hyperechogenicities. The images were analyzed for the presence and the grade of the artifact. Phantom study demonstrated the constant occurrence of the artifact regardless of the mineral composition of uroliths. Mottled and rough surfaced stones produced higher grades of twinkling artifact. High-grade, color-twinkling artifact generated by stones occured frequently in vivo. Bladder crystalluria was more frequently detected by artifact visualization than sample urinalysis performed by cystocentesis. In veterinary medicine, twinkling artifact may thus be considered an additional sonographic feature of urinary stones, and can lead to a more appropriate management of patients presenting gray-scale sonographic focal hyperechogenicities.

Ultrasonographic diagnosis--small bowel lymphangiectasia in a dog.

A 7-year-old, West Highland White Terrier had a 5-month history of diarrhea, dysorexia, and weight loss. Sonographically, there was a focal area of intestinal thickening with loss of layering. A neoplastic or severe inflammatory condition was suspected and intestinal lymphangiectasia was diagnosed histopathologically. This patient seems to be the first description of intestinal lymphangiectasia appearing as an intestinal mass.