We have developed a digitally synthesized patient which we call “Zach” (Zero millisecond Adjustable
Clinical Heart) phantom, which allows for an access to the ground truth and assessment of image-based
cardiac functional analysis (CFA) using CT images with clinically realistic settings. The study using Zach
phantom revealed a major problem with image-based CFA: "False dyssynchrony." Even though the true
motion of wall segments is in synchrony, it may appear to be dyssynchrony with the reconstructed cardiac
CT images. It is attributed to how cardiac images are reconstructed and how wall locations are updated
over cardiac phases. The presence and the degree of false dyssynchrony may vary from scan-to-scan,
which could degrade the accuracy and the repeatability (or precision) of image-based CT-CFA exams.