Research Update: Using computed tomography to find nongastrointestinal foreign bodies
In this retrospective study, the clinical and computed tomography (CT) characteristics of 13 cases involving nongastrointestinal foreign bodies in dogs evaluated at a university veterinary hospital were reviewed. Diagnosis was confirmed by using direct visualization or histologic examination.
Most foreign bodies were identified in the nasal cavity or nasopharynx (9). Two foreign bodies involved the retropharyngeal region, and one each involved the cerebellum and thoracic wall. Most foreign bodies were of plant origin (10). Large plant foreign bodies included sticks (3), grass blades (2), and evergreen sprigs (1).Dogs with nasal foreign bodies most commonly had chronic nasal discharge (7). In eight of the 11 dogs with known outcomes, clinical signs resolved after the foreign bodies were removed.
Foreign bodies were not identified on CT in five dogs, and four of these had confirmed plant foreign bodies. Secondary reactions (soft tissue mass, bone lysis) in these dogs appeared similar to fungal or neoplastic diseases. In two dogs, three-dimensional reformatting helped identify foreign bodies adjacent to bony landmarks. The authors concluded that CT was useful in delineating nongastrointestinal foreign bodies but was not definitive.
Nongastrointestinal foreign body granulomas, abscesses, and draining tracts can be frustrating to treat because of difficulties in localizing the cause and completely excising affected tissues. Routine tests in private practice include radiography, ultrasonography, and sinography. Exploratory surgery is also often used. This study's results may offer practitioners an additional noninvasive imaging modality to determine the location and characteristics of a foreign body, although ct is probably limited to a university or specialty-practice setting. Although the data reveal that ct may not yield diagnostic information in every case, the technique should perhaps be pursued in patients with recurrent or incompletely excised lesions or with deep-seated, internal (thoracic, cervical, spinal) foreign bodies. A radiologist's assistance is critical in identifying the ct characteristics of a foreign body or creating three-dimensional reformatted images to pinpoint a foreign body's location.
Jones JC, Ober CP. Computed tomographic diagnosis of nongastrointestinal foreign bodies in dogs. J Am Anim Hosp Assoc 2007;43:99-111.