All CT imaging was performed using 64-slice (Toshiba, Aquilion 64, Japan) or 128-slice (GE, Revolution EVO, USA) multi-detector CT scanners with the following parameters: 1:0.984/1.35 pitch, automated dose modulation (200-350 mAs), 120 kVp, and 05-0.625 mm isotropic spatial resolution. The subjects were examined in a supine position with their arms extended above their heads.
Weight-adapted (1-1.5 ml/kg, maximum allowable 150 ml) iodinated intravenous contrast agent was administered through the antecubital veins with an automatic injector at a rate of 3 ml/s. 20 ml saline was injected both prior to and following the injection of the contrast media, with the same flow rate. Optimal scan time was detected by the automated bolus tracking method by placing the region of interest over the descending aorta and setting the trigger threshold to 150 HU and 40-s delay time. Images were obtained in portal venous phases.
Weight-adapted (1-1.5 ml/kg, maximum allowable 150 ml) iodinated intravenous contrast agent was administered through the antecubital veins with an automatic injector at a rate of 3 ml/s. 20 ml saline was injected both prior to and following the injection of the contrast media, with the same flow rate. Optimal scan time was detected by the automated bolus tracking method by placing the region of interest over the descending aorta and setting the trigger threshold to 150 HU and 40-s delay time. Images were obtained in portal venous phases.