Objective To assess the clinical usefulness of 64-slice spiral CT pulmonary angiography (CTPA)in diagnosing of pulmonary embolism.

Methods Sixty-three patients with clinically known pulmonary embolism underwent 64-slice spiral CTPA.The source images of all the patients were reconstructed with the 3D techniques including multiplanarreconstruction, maximum intensity projection and volume rendering, CT axial images features were analyzed.

Results Three hundreds and three embolus were found in 63 cases patients.The direct diagnostic findings of pulmonary embolism including: 64-slice spiral CTPA clearly showed the sites, extensions and stenosed lumens of pulmonary embolism in all patients.Pulmonary embolism lesions appeared as intra-luminal irregular-plaque shape and adhered-mural filling defects.The indirect diagnostic findings of pulmonary embolism including: dmosaic signs, dilation of the right ventricle and atrium, pulmonary artery enlargement, pleural effusion, pulmonary atelectasis and pulmonary consolidation(pulmonary infarction).There are 47 patients whose thrombosis disappeared after therapy in 62 patients, 11 became smaller and 3 were chronic pulmonary embolism.

Conclusion 64-slice spiral CTPA is one of the most effective and non-invasive imaging modalities in the diagnosis before and aftertherapy of pulmonary embolism.