Reconstructing the activity surface for cardiac PET imagery

A simple method for constructing and displaying activity surfaces obtained by a sequence of successive positron emission tomography (PET) sections is presented. The shape of the surface of activity is reconstructed showing intrusions and protrusions in a 3-D environment. The normal activity of the cardiac muscle leads generally to a homogeneous distribution of the tracer inside the organ. This generates a smoothed activity surface frequently coinciding with the external boundary of the cardiac muscle. By performing a segmentation of the successive slices obtained by a PET scanner and combining them into a 3-D stack, it was possible to reconstruct on a graphic display screen, a 3-D representation of the surface of activity. A numerical evaluation of protrusions and intrusions could be attempted to numerically represent the characteristics of that surface