Pneumocoelomogram as a novel negative contrast diagnostic imaging technique to evaluate coelomic organs in bearded dragons (Pogona vitticeps)

Background: Contrast radiography is used to combat poor coelomic detail encountered in reptilian radiographs. This study describes pneumocoelomography, a novel negative contrast technique using room air in bearded dragons (Pogona vitticeps). The feasibility of this technique, its tolerance by the study subjects, and obtained images were evaluated. Methods: Six clinically healthy, adult bearded dragons had standard and pneumocoelomogram radiographs performed under anesthesia. Pneumocoelom was induced by insufflating 0.2 mL/mm coelomic length of room air via an over-the-needle catheter introduced into the coelom. Pre-, post-, and positive intravenous contrastenhanced postpneumocoelom computed tomography scans were also performed. Packed cell volume, total protein, and blood films were evaluated at time of imaging and two weeks postprocedure to assess potential systemic consequences of this technique. Results: Procedures were well tolerated with no adverse anesthetic, recovery, postprocedural, hematologic, or behavioral declines in health status. The pneumocoelomogram consistently revealed the gonads (6/6 cases) in both sexes. There was an inconsistently improved characterization of other coelomic organs: the cardiac silhouette was improved in 4 of 6 cases, trachea in 2 of 6, lungs in 3 of 6, stomach in 3 of 6, cecum in 3 of 6, colon in 5 of 6, and kidneys in 2 of 6. The liver, spleen, and small intestines did not show improved characterization in any case. Conclusion: Room air pneumocoelomography offers a well-tolerated, readily-available technique and provides additional coelomic organ characterization to that of standard radiographs. Future studies should evaluate if this technique provides diagnostic utility in pathological states.