Preoperative diagnosis of tumors of the brachial plexus by use of computed tomography in three dogs.

Three dogs with forelimb lameness of 3 months' to 1 year's duration were examined by computed tomography and determined to have a tumor of the brachial plexus. In each case, the clinician had been unable to determine the cause of lameness by other means, and in 2 dogs, surgery had been performed on the affected limb for unrelated conditions prior to diagnosis of the tumor. Computed tomography was performed by use of a third-generation scanner, with dogs under general anesthesia and positioned in dorsal recumbency. Intravenous contrast enhancement with iodinated contrast material was used to help differentiate vascular structures, and a 5-mm scanning width allowed detection of small tumors. In all dogs, approximate tumor location in the transverse plane, invasiveness, and relationship to surrounding structures compared favorably between computed tomographic images and surgical findings.