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Cranio-caudal respiratory motion and liver activity cause a variety of complex myocardial perfusion (MP) artifacts, especially in the inferior myocardial wall, that may also mask cardiac defects. To assess and characterise such artifacts, an anthropomorphic thorax with moving thoracic phantoms can be utilised in SPECT MP imaging. In this study, a liver phantom was developed and anatomically added into an anthropomorphic phantom that also encloses an ECG beating cardiac phantom and breathing lungs’ phantom. A cranio-caudal respiratory motion was also developed for the liver phantom and it was synchronised with the corresponding ones of the other thoracic phantoms. This continuous motion was further divided into isochronous dynamic respiratory phases, from end-exhalation to end-inspiration, to perform SPECT acquisitions in different respiratory phases. The new motions’ parameters and settings were measured by mechanical means and also validated in a clinical environment by acquiring CT images and by using two imaging software packages. To demonstrate the new imaging capabilities of the phantom assembly, SPECT/CT MP acquisitions were performed and compared to previous phantom and patients studies. All thoracic phantoms can precisely perform physiological motions within the anthropomorphic thorax. The new capabilities of the phantom assembly allow to perform SPECT/CT MP acquisitions for different cardiac-liver activity ratios and cardiac-liver proximities in supine and, for first time, in prone position. Thus, MP artifacts can be characterised and motion correction can be performed due to these new capabilities. The impact of artifacts and motion correction on defect detection can be also investigated.

Cranio-caudal respiratory motion and liver activity cause a variety of complex myocardial perfusion (MP) artifacts, especially in the inferior myocardial wall, that may also mask cardiac defects. To assess and characterize such artifacts, an anthropomorphic thorax with moving thoracic phantoms can be utilized in SPECT MP imaging. In this study, a liver phantom was developed, and anatomically added into an anthropomorphic phantom, that encloses an ECG beating cardiac phantom and breathing lungs phantom. A cranio-caudal respiratory motion was also developed for the liver phantom and it was synchronized with the corresponding ones of the cardiac and lungs phantoms. This continuous motion could also be further divided into dynamic respiratory phases, from end-exhalation to end-inspiration, to perform SPECT acquisitions in different respiratory phases. The motion parameters, displacements and volumes, were validated by the acquired CT slices, the OsiriX and Vitrea software. Sample SPECT/16-slice-CT myocardial MP acquisitions were also performed and compared to the literature. The cardiac, lungs and liver phantoms can precisely perform, in time interval of 0.1 sec, physiological thoracic motions within an anthropomorphic thorax. This dynamic phantom assembly can be utilized for SPECT MP supine and, for first time, prone imaging to access and characterize artifacts due to different cranio-caudal respiratory amplitudes and cardiac-liver activity ratios.

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