Carbon Dioxide Contrast Enhancement for C-Arm CT Utility for Treatment Planning during Hepatic Embolization Procedures

A pilot study was performed to evaluate the use of carbon dioxide (CO₂) as a contrast medium for C-arm computed tomography (CT). C-arm CT using CO₂ was performed during embolization procedures in12 patients with hepatic malignancies and severe iodine allergy or high risk for nephrotoxicity. C-arm CT using gadolinium or iodinated contrast medium was performed for comparison. Of segmental arteries identified by conventional contrast enhancement, 96% were also seen with CO₂ enhancement, but subsegmental arteries were not reliably depicted. CO₂ enhancement identified 60% of tumors. Small, hypovascular, and infiltrative tumors were difficult to detect. CO₂ is a promising alternative intraarterial contrast agent for C-arm CT.