Imaging in sitting position may reduce liver artifact in myocardium perfusion imaging

In this work we evaluated liver artifacts in SPECT myocardium perfusion imaging. Liver artifact occurs due to the liver-heart proximity and is manifested as an apparent increase or decrease in radioactive uptake in myocardium. The main motivation for the work is that there are now SPECT imaging devices on the market that image patients in an upright seated position, as opposed to the conventional supine position. The upright position may aid in removal of the artifact during reconstruction by causing the liver to sag downward, thus increasing liver-heart distance. In this work we investigate whether this change of the liver-heart distance can result in more accurate image reconstructions, and thus lower myocardium defect misdetection rates. To investigate this we use the realistic NCAT phantom to simulate the human torso, and SIMIND simulation code.