If there is a reduction of counts in the basal, mid-basal or mid-apical regions of the septal sides of the inferoseptal and anteroseptal myocardial walls, then there is evidence of a perfusion defect in the septal myocardial wall.

There is a reduction in the mid-basal and mid-apical regions of the septal side of the inferoseptal myocardial wall, and in the mid-basal and mid-apical regions of the septal side of the anteroseptal myocardial wall.