CARBON DIOXIDE ANGIOGRAPHY: SIMULATION OF OPERATIVE CONDITIONS FOR DIAGNOSTIC IMAGE OPTIMIZATION

Carbon dioxide angiography is based on the visualization (i.e., the radiographic contrast) of gas bubbles injected in blood vessels. By using an experimental X-ray bench, the energy response of a flat panel detector has been measured (Varian CB4030) and, with a dedicated phantom and a software simulation, the image contrast of vessels is injected with Iodine and CO2. Moreover, the dynamical behavior of a moving gas bubble has been studied with the software simulator. The results show that the contrast generated by carbon dioxide is about one fourth of that obtained with iodine, demonstrating that CO2 angiography should use different radiological settings with respect to iodine angiography. In particular, a kVp increase has a lower reduction of contrast-to-noise-ratio (CNR) with carbon dioxide than with iodinated contrast medium (CM), suggesting possible technological improvements both on radiological emission and image enhancement methods.