Imaging of Spontaneous Canine Tumors with Ammonia and L-Glutamine Labeled with N-13

Ammonia and 6-glutamine, labeled with N-13, were tested as imaging agents for a variety of spontaneous canine tumors. The imaging capabilities of these compounds were compared with each other, with other scanning agents, and with radiologic and pathologic procedures. Good agreement between positive gamma images and postmortem findings occurred in 11 of 15 cases with [13N] ammonia as the localizing agent. Eight of the nine scans using [13N] glutamine as the imaging agent showed positive correlation with postmortem findings. In cases where both ammonia and glutamine were used to image the same lesion, no qualitative differences in tumor uptake were found between the two.