CT image acquisition
epiglottis, flushing
BEST
Chest CT was performed in both the arterial and venous phases on a SDCT (IQon Spectral CT, Philips Healthcare, Best, The Netherlands). All the patients were in the supine position, with both arms raised and breathing calmly; while holding the breath, scanning range was from the epiglottis to the costophrenic angle to ensure coverage of all esophageal and lung tissues. Before initiating contrast-enhanced scanning, 70 ml contrast medium (Ultravist injection at a concentration of 300 mg/ml; Bayer, Leverkusen, Germany) was injected through the elbow vein at a rate of 2.5 ml/s using a power injector. After the injection, 20–30 ml of normal saline was injected for flushing at a rate of 3 ml/s. Arterial and venous phase images were acquired at 25s and 60s. The following scanning parameters were used: detector collimation, 64 × 0.625 mm; tube voltage, 120 kV; tube current, 180–250 mA; rotation speed, 0.33s/rot; helical pitch, 0.671; matrix, 512 × 512.