IMAGING DIAGNOSIS: MAGNETIC RESONANCE IMAGING OF A CERVICAL WOODEN FOREIGN BODY IN A DOG

This article describes the discovery of a chronic cervical wooden foreign body ventral to the left transverse processes of the cranial cervical spine using magnetic resonance imaging (MRI) in a dog that presented with chronic neck pain and lameness. The dog did not exhibit dysphagia or chronic draining tracts, the most common signs of the presumed cause, that of a penetrating oropharyngeal foreign body. The foreign body itself was represented on MR images as an oval straight-edged core within an inflammatory tissue reaction. The wood was slightly hyperintense on T2- and isointense on T1-weighted images relative to muscle. Surrounding this was a more conspicuous contrast-enhancing reactive tissue rim that was hyperintense on all pulse sequences. Adjacent musculature also exhibited diffuse edema and contrast enhancement that extended around the left cervical vertebral transverse processes and local intervertebral nerve roots. The foreign body was found to be a wooden stick upon surgical removal. MRI is an excellent method for visualizing the inflammatory tissue reactions associated with soft-tissue foreign bodies because of its contrast resolution and depiction of anatomy in multiple imaging planes.     

PREGNANCY DIAGNOSIS WITH ULTRASOUND IN THE DOMESTIC CAT

Ultrasonographic examinations of seven pregnant cats with known breeding dates were made on successive days to establish the identifiable characteristics of pregnancy. Subsequent serial examinations were made to sonographically characterize normal feline prenatal development before 30 gestational days. An enlarged uterus, gestational sacs, and fetal poles were recognized as the features of early feline pregnancy and were first seen at 4, 11, and 15 days, respectively. Cardiac activity was detected earliest on gestational day 16, and recognizable feline fetal morphology appeared at day 26. Fetal membranes became apparent at as early as 21 days of gestation. Generalized fetal movements were first noted at day 28. Live and dead fetuses were compared in utero and marked differences were noted, with dead fetuses rapidly losing previously recognizable morphology. Determination of litter size in each cat could not be done accurately by ultrasound examination. It was concluded that the diagnosis and accurate dating of early pregnancy in the domestic feline may be accomplished with serial ultrasound evaluation.     

SUBCUTANEOUS FOREIGN BODY IN A HORSE RESEMBLING FISTULOUS WITHERS

This clinical report describes the ultrasonographic and radiographic evaluation of a horse presented for fistulous withers. A metal foreign body resulting in a draining tract in the area of the withers was identified and surgically removed.     

SONOGRAPHIC SIGNS OF GASTRODUODENAL LINEAR FOREIGN BODY IN 3 DOGS

This article describes the sonographic signs identified in three dogs with confirmed gastroduodenal linear foreign bodies. The sonographic signs included the following; an abnormal tortuous path of the descending duodenum, the presence of a hyperechoic linear structure within the duodenal lumen which was carefully followed orally to the pylorus. The presence of a mass with strong acoustic shadow within the pylorus may also be imaged. The normal intestinal layers were present in the duodenal wall. In real time, the intestinal path was followed through many "hairpin" turns, and during this process the lumen was observed for identification of a linear structure. Secondary sequelae of gastrointestinal perforation were more difficult to identify with confidence in the cases presented.     

ULTRASOUND AS AN AID FOR DIAGNOSIS OF OVARIAN ABSCESSES IN TWO MARES

This report describes two mares presented for evaluation of anorexia, fever of unknown origin, and weight loss. Clinical examination, laboratory findings, and transrectal ultrasonographic images suggested ovarian abscessation. One mare was successfully treated medically. Because of financial considerations, the second mare was euthanatized and a postmortem examination was performed. At necropsy, there was an enlarged right ovary with an adhesion to the large colon. Microscopic findings were characteristic of an ovarian abscess.     

DIAGNOSIS OF URINARY BLADDER RUPTURE USING ULTRASOUND CONTRAST CYSTOGRAPHY: IN VITRO MODEL AND TWO CASE-HISTORY REPORTS

Because urinary bladder rupture can be life threatening, a simple, safe technique for evaluating patients is desirable. Current diagnostic protocols involve radiographic imaging, but ultrasound-based contrast techniques have not been methodically evaluated in veterinary patients with urologic trauma. Ultrasound contrast cystography (contrast cystosonography) involves infusion of microbubbled saline solution through a urinary catheter. It was performed in an in vitro model and in 2 dogs with naturally occurring urinary bladder rupture. A positive result consisted of visualizing microbubbles sonographically in fluid surrounding the bladder immediately after infusion of contrast into the urinary catheter. A positive result was obtained both in the in vitro model and in the 2 dogs, with radiographic and surgical confirmation of naturally occurring intraperitoneal urinary bladder rupture in the dogs. Based on the results of this study, ultrasound contrast cystography appears to be more sensitive than two-dimensional (2D) abdominal sonography for detecting naturally occurring urinary bladder rupture 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.     

ULTRASONOGRAPHIC DIAGNOSIS OF FOREIGN BODIES ASSOCIATED WITH CHRONIC DRAINING TRACTS AND ABSCESSES IN DOGS

This is a retrospective study that describes the historical, physical exam, radiographic, fistulographic, ultrasonographic, and surgical findings associated with non-gastrointestinal and extrathoracic foreign bodies in six dogs. All dogs had a chronic draining tract or abscess. Although radiographs were obtained in five of the six dogs, no foreign bodies were identified with this modality. Fistulography was performed in four of the six dogs, and a filling defect consistent with a foreign body was found in two of four dogs. A foreign body was identified in five of the six dogs with ultrasound. Foreign bodies were removed surgically in five of six dogs. This report clarifies the importance of ultrasound in the evaluation of chronic draining tracts and abscesses in dogs.     

IMAGING DIAGNOSIS—EXTRAHEPATIC BILIARY TRACT OBSTRUCTION SECONDARY TO A DUODENAL FOREIGN BODY IN A CAT

A 13-month-old, neutered female domestic shorthaired cat was evaluated for vomiting, anorexia, and lethargy. The cat was icteric and hyperbilirubinemic. Radiographically a partially radiolucent proximal duodenal foreign body was suspected. Ultrasonographically, there was a foreign body at the level of the duodenal papilla and dilation of the common bile duct and cystic duct; a diagnosis of extrahepatic biliary tract obstruction secondary to a duodenal foreign body was made. Sonographic findings were confirmed at surgery and a duodenal foreign body was removed. This information defines duodenal foreign body as a cause of extrahepatic biliary obstruction in cats.