Objective To evaluate the application value of test bolus injection combined with pulmonary artery trunk area measurement method in pulmonary artery CTA.Methods 32 pulmonary artery CT patients examined on Phillips 128-row ICT from July 2017 to may 2018 were retrospectively selected.the method of small dose bolus injection combined with ellipsometry in the main pulmonary artery was used.the peak time of contrast agent plus 1 second was used as the delay time of image acquisition of pulmonary artery CTA.The r...