Advances of ventilation/perfusion scintigraphy in diagnosing acute pulmonary embolism

Abstract

PE is a severe and potentially fatal disease.Early and accurate diagnosis of PE is crucial.Lung scintigraphy is a non-invasive imaging technique to diagnose PE.Recently,major research advances have been achieved in V/Q scintigraphy.The prospective investigation of PE diagnosis (PIOPED)Ⅰcriteria was formalized in the 1990s.In the PIOPED study,the majority of patients had either intermediate probability results or low probability results.Accordingly,the PIOPED Ⅰcriteria were fundamentally flawed.Many investigators established new criteria,such as PIOPED Ⅱ,prospective investigative study of acute pulmonary embolism diagnosis (PISAPED) and European Association of Nuclear Medicine(EANM).With the use of SPECT acquisition,the V/Q scan has undergone a transition to three-dimensional volumetric imaging.SPECT has a higher spatial resolution than planar V/Q scintigraphy,so it can detect abnormalities particularly at the subsegmental level and in the lung bases,where the segments are tightly packed.SPECT V/Q has proven to be clearly superior to planar V/Q and multi-detector CT (MDCT).When SPECT and CT images are acquired on the same scanning bed in the same imaging session,great registration accuracy is achieved with such SPECT/CT scanners.For lung imaging,the emergence of SPECT/CT scanners gives reporting specialists two options to combine structural and functional data and potentially to improve the overall diagnostic accuracy of the modality. Key words: Pulmonary embolism; Radionuclide imaging; Tomography, emission-computed,single-photon; Tomography,X-ray computed; Trends