Design and fabrication of pulmonary embolism phantom for planar and SPECT V/Q imaging quality assurance

Planar and Single Photon Emission Computed Tomography (SPECT) scintigraphy are the two main modalities for pulmonary embolism (PE) diagnosis via lung ventilation/perfusion (V/Q) scans. This study aims to develop an anatomical lung phantom for the quality assurance (QA) of V/Q scans using planar and SPECT imaging. The phantom consists of two hollow anatomical lung cavities and 20 solid anatomical bronchopulmonary segments. The phantom functions as a PE simulator by enabling an interchangeable perfusion defect, represented by a solid anatomical bronchopulmonary segment, to be introduced into each of the lung cavities. These cavities are filled with expanded polystyrene (EPS) beads immersed in a 99mTc solution, which simulates the alveoli. The anatomical 'dead space' due to the solid introduced segment represents a perfusion defect in lung V/Q scans. In this study, a sample anatomical PE event was simulated. The phantom was prepared with a perfusion defect within the posterior basal segment in the left lung. Images were acquired for subsequent qualitative analysis. This study has demonstrated promising results in the simulation of PE events in lungs. Further development is warranted for the phantom to be used as a viable QA tool in V/Q lung scanning using planar or SPECT imaging.