Biomedical Engineering Reference
In-Depth Information
FIGURE 11.11
A SPECT stress
rest myocardial perfusion study (upper rows), spatially normalized and
displayed as a polar plot (lower two images) for all slices, is shown. The top two rows show
reconstructed sections through the left ventricle of the heart when the tracer was injected
while the heart was being stressed. The sections are sliced from apex towards the base of
the heart (the valve plane). The next two rows show the same heart after the tracer has been
injected at rest. The polar plots on the bottom for stress (left) and rest (right) condense the
multiple slices into a single display, where the apical slices are located in the center of the
image and the basal slices are at the edges. There is a small “notch” of decreased perfusion
at stress in the upper section of the reconstructions (labeled 7-10, top row) which corre-
sponds to the anterior myocardial wall, and which is normal at rest. This is seen in the top
half, center, of the polar plots. Once the data are in this standard representation, they can
be compared with a data base of ”normals” to assess the significance of the defects. The
large dark area at the lower right half of the polar plots corresponds to the valve plane of
the heart where there is little myocardium, and is a normal appearance.
