Objective To study the application of pulmonary angiography and reconstruction techniques with 16-detector row spiral CT in the diagnosis of pulmonary embolism (PE) in the elderly.Methods Twenty-four elderly patients with suspected pulmonary thromboembolism received detection of CT and pulmonary artery angiography ( CTPA ) on 16-detector MSCT.Post-reconstruction techniques included maximum intensity projection (MIP), volume rendering (VR)and multiple planar reformation (MPR). Results A total of 161 pulmonary artery thrombi were detected in 24 elderly patients. The direct signs of pulmonary embolism included total occlusion (16.8%, 27/161), partial filling defect (67.7%, 109/161) and central filling defect or track sign (15.5%, 25/161). A total of 161 pieces of pulmonary thrombi were detected in transect image, 153 (95.0%) in MPR, 113 (70.2%) in MIP and 69 (42.9%) in VR. The transect image excelled evidently MIP and VR image in displaying pulmonary thrombi, especially the thrombi in pulmonary lobe and pulmonary artery branch (χ2 =235.36 and 243.41, P＜0.05). Conclusions The 16-detector row spiral CT pulmonary angiography is non-invasive, fast and high sensitive, it should be the first choice for the diagnosis of PE in the elderly.