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. Excellent opacification of the pulmonary veins was observed in 66% of patients injected at 3 mL/sec and in 56% of patients injected at 4 mL/sec (p > 0.192). A highly significant difference was noted for pulmonary artery enhancement. Excellent opacification of the pulmonary arteries was noted in 83% of patients injected with a 3mL/sec flow rate and in 61% of patients injected with a 4 mL/sec flow rate (p = 0.001).
CONCLUSION: A high level of opacification of hilar pulmonary vessels, with no major perivenous artifacts, can be obtained with a small amount of nonionic contrast medium using a simple bolus injection.

RCT Entities:   Population Interventions Outcomes