Chronic Obstructive Pulmonary Disease: CT Features of Severe Exacerbation

CT examinations were performed with a commercially available 64-detector row scanner. Images were acquired in supine position after full inspiration and full expiration, using the following parameters: slice thickness, 0.6 mm; pitch, 1.4; rotation time, 330 msec; tube voltage, 120 kiloVolts; and tube current-time product, 100 milliAmperes, with automatic exposure control (CareDose 4D, Siemens Healthcare) switched on. From raw data, 1-mm-thick section images were reconstructed at 0.7-mm intervals by using a high spatial algorithm and a soft-tissue algorithm. The inspiratory CT scan at the time of exacerbation was performed with intravenous iodinated contrast material, whereas the control scan was unenhanced.