Pulmonary CTA examination is pulmonary CTA examination is angiographic CT, mainly to see whether there are lesions in the pulmonary artery vessels, mainly by pushing contrast agent into the patient intravenously for contrast, according to the patient’s blood circulation status, in the lung is the optimal contrast concentration in the vessels of the artery CT scan of the pulmonary artery vessels, and then through the computer for post-processing, the reconstruction of the vessels, so as to The CT scan can be used to locate the size and extent of the lesion and to diagnose and treat the disease. CTA is now widely used, and is the main diagnostic tool for common clinical applications when considering pulmonary embolic disease.