Evaluation of (99)mTc-citrate, Ga-67-citrate and Tc-99m(V) dimercaptosuccinic acid for the scintigraphic visualization of acute appendicitis

An experimental study was planned to evaluate Tc-99m-citrate, Ga-67-citrate and Tc-99m(V) dimercaptosuccinic acid (DMSA) as agents for the visualization of acute appendicitis. Appendiceal ligation was performed through a midline incision in 24 rabbits. Twenty-four hours later the animals were divided into three equal groups. The rabbits were injected through the aurical vein with 1 mCi (37 MBq) Tc-99m-citrate in group I, 0.5 mCi (18.5 MBq) Ga-67-citrate in group II and 1 mCi (37 MBq) Tc-99m(V) DMSA in group III. After 3 h, static images of the rabbits were obtained with a gamma camera. There were positive images in seven, six and five rabbits in groups I, II and III respectively. The image quality was better in group I than in the other groups. Also, the mean uptake in group I was significantly higher than those of other two groups (P < 0.05). There was no significant difference between groups II and III (P > 0.05). All rabbits had appendicitis confirmed histologically. In conclusion, these results show that Tc-99m-citrate is preferable to Ga-67-citrate and Tc-99m(V) DMSA for the differential diagnosis of acute abdominal inflammations such as appendicitis, because of higher concentration ratios, simple and rapid preparation, low cost, excretion mainly through the kidneys and fast blood clearance.