High Opacification of Hilar Pulmonary Vessels with a Small Amount of Nonionic Contrast Medium for General Thoracic CT: A Prospective Study

OBJECTIVE. The main goal of this study was to determine whether in thoracic helical CT for general indications a high opacification of hilar pulmonary vessels could be obtained using a small amount of nonionic contrast medium.SUBJECTS AND METHODS. Two hundred consecutive patients referred for contrast-enhanced thoracic CT for malignancies or infections prospectively entered the study. They were randomly assigned to one of two simple bolus injection protocols (100 patients in each protocol): 60 mL of a nonionic contrast agent (250 mg I/mL) injected at a 3 mL/sec flow rate, or 80 mL of the same contrast agent injected at a 4 mL/sec flow rate. No saline flush or bolus triggering system was used. Hilar and mediastinal vessel enhancement was qualitatively (using a 4-point scale) and quantitatively (arterial attenuation values) assessed. Perivenous artifacts were also assessed.RESULTS. No extensive perivenous artifacts were noted. No significant difference was noted regarding pulmonary venous enhancement. Excel...