The role of nuclear medicine in pulmonary embolism

Nuclear medicine procedures and mainly perfusion lung scanning (often associated with ventilation lung scanning), after thirty years still play a major role in the diagnosis of pulmonary embolism. International study groups with accurate statistical methods have shown their efficacy in the diagnosis and follow-up, in reducing the clinical uncertainty, in directing the therapy and in lowering health care costs. The major limitation of nuclear medicine procedures lies in the high percentage of patients for whom intermediate or indeterminate probability is reported. However this percentage is steadily decreasing based on: patient clinical preselection; improved procedures and especially an extensive use of D-SPET with a three-head gamma camera; the combination with other advanced diagnostic imaging procedures (HRCT, fast-CT, MRI); suitable diagnostic algorithms for nuclear medicine procedures which should consider laboratory data (D-dimer, TAT) and the study of deep vein thrombosis; the use of artificial intelligence; the introduction of radiopharmaceuticals which enable direct scanning of the intravasal embolus (as P180 polypeptide) in combination with perfusion scanning which shows the hemodynamic alterations.