Current Role of lung scintigraphy in pulmonary embolism

The pivotal role of lung scintigraphy in the diagnosis of pulmonary embolism (PE) has been questioned in recent years due to the introduction of spiral computed tomography. However, the scintigraphic results used for comparisons are often those of the authoritative PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) study, carried out in the 1980s. Pulmonary scintigraphy has progressed from those years both in the methodological and interpretative fields, although perhaps too slowly. Results better than those of PIOPED's have been presented by study groups who used: 1) perfusion-only approach, 2) SPET imaging; 3) new interpretative criteria; 4) different prediction rules to integrate clinical and scintigraphic probabilities of PE. These advances are still insufficiently recognised by the nuclear medicine community, possibly due to a sort of PIOPED-based "cultural globalisation". This paper reviews the actual advantages and limitations of nuclear medicine techniques, the diagnostic role of scintigraphy within the diagnostic algorithms proposed by international working groups and scientific societies and the results obtained from SPET imaging in the diagnosis of PE.