Sequential feline esophageal nutrient blood flow: perfusion measurements in vivo

The utilization of a catheter semiconductor beta detector (CASRAD) to perform in vivo, sequential, esophageal nutrient blood flow distribution studies in cats is described. A diffusable radioisotope, Rubidium 86 (86Rb), was injected intravenously and the CASRAD placed within the esophageal lumen. The distribution of 86Rb remained stable within the feline esophagus for sufficient time to allow for counting at 1.5 cm levels in the esophagus. The accuracy limitations of the CASRAD system were assessed by comparing the in vivo, recorded distribution of 86Rb with the esophageal distribution of 86Rb as determined by a well-type scintillation counter. The distribution throughout most of the esophagus was similar by both techniques. Sequential esophageal studies performed with the CASRAD showed less variability than existed in the biological differences between cats and the methodology of obtaining and counting tissue by well-type scintillation counter (mean coefficient of variation 11.6% versus coefficient of variation 23.1%).