CO2 angiography of transplanted kidneys

PURPOSE: To compare image quality and diagnostic accuracy of carbon dioxide (CO2) and iodinated contrast medium as a contast medium in renal transplant artery angiography. MATERIAL AND METHODS: In this prospective, non-randomized, intra-individual study, we examined 17 patients. Digital subtraction angiography (DSA) was performed first with CO2 to find the optimal projection. Then at least one confirming run was performed with CM ("gold standard"). The quality of the angiographic studies with CO2 and CM and their diagnostic accuracy were compared. Blood creatinine levels were monitored during three days after angiography. RESULTS: Three of four renal transplant artery stenoses were diagnosed correctly with CO2. The false-negative CO2 angiography was due to poor contrast. There were no false-positive results with CO2. Regardless the inferior image quality of CO2 angiography, its positive predictive value was 100%. Renal function was not compromised. CONCLUSION: The primary use of CO2 as a contrast medium for the angiographic evaluation of renal transplant arteries is feasible and practical. It reduces the amount of CM needed. However, in order to confirm the diagnosis, at least one additional series with CM should be performed.