[Single-phase Pulmonary Arteriovenous Separation CT Protocol with Estimated Time of Arrival Method Using 3rd Generation Dual Source CT: Its Success Rate of Pulmonary Arteriovenous Separation in Our Experience of 223 Cases].

We retrospectively investigated the success rate of pulmonary arteriovenous separation in a single-phase computed tomography (CT) protocol using the estimated time of arrival (ETA) method. A total of 223 patients who underwent a single-phase CT protocol using the ETA method for pulmonary arteriovenous separation were included in the analysis. Dual source CT (SOMATOM Force, SIEMENS) was used for imaging. The tube voltage was 80 kVp, and the scan mode was turbo flash spiral mode. CT values of main pulmonary artery (MPA), peripheral pulmonary artery (pPA), peripheral pulmonary vein (pPV), left atrium (LA), ascending aorta (AAo) and descending aorta (DAo) were measured. When the difference in CT values on the central side was 100 Hounsfield unit (HU) or more, it was judged that the separation was successful. The mean CT values were 671.9±154 HU for MPA, 424.4±81.2 HU for LA, 551.1±142.6 HU for pPA, 351.6±94.0 HU for pPV, 362.2±75.8 HU for AAo, and 282.7±83.7 HU for DAo. The mean difference in CT values of the pulmonary artery and vein was 247.5±138.9 HU on the central side and 199.5±133.0 HU on the peripheral side. There were 90.1% of cases where the difference in CT values on the central side was 100 HU or more. In addition, a strong positive correlation (r=0.849, p<0.001) was found between the CT value of MPA and the CT value difference on the central side. The success rate of pulmonary arteriovenous separation by the ETA method, which is a method that enables stable pulmonary arteriovenous separation, was 90.1%.