Pulmonary angiography is considered the gold standard for the diagnosis of PE, although recent evidence does not necessarily always support that. Pulmonary angiography is an invasive procedure and due to its costs and potential risks is usually reserved for patients in whom more information or certainty of the diagnosis of PE are necessary. Indications for angiographic evaluation of patients suspected of having PE are the need to confirm the diagnosis of PE in the presence of contraindications to anticoagulation or if IVC filter placement or surgical embolectomy are contemplated. In addition, patients with a high index of clinical suspicion but nondiagnostic noninvasive studies and patients with pulmonary hypertension of unknown cause commonly undergo the exam . The unequivocal establishment of the diagnosis of PE in younger patients facing life-long anticoagulation therapy or IVC filter placement is another indication. With modern techniques and nonionic contrast media, the risks of the procedure are exceedingly low with major nonfatal complication rates less than 2% and a mortality of the procedure of 0.1%.

Life threatening complications are typically secondary to acute cor pulmonale in patients with pre-existing severe pulmonary hypertension and failing right ventricle. Therefore, the measurement of the right ventricular enddiastolic pressure (RVEDP) is mandatory before performing the angiographic runs and if this is 20 mmHg or higher it should be acknowledged that the patient has a significantly higher risk of a serious complication and therefore either should not have the study performed or have a superselective study using more runs with smaller amounts of contrast. It has been shown that digital angiography helps to reduce both time and amount of contrast necessary to perform pulmonary angiography if compared to conventional cut-film angiography. It also has been shown to have similar performance without sacrifices in sensitivity or specificity.