FIGURE 5. Visualization of the stress–rest change estimated to be 4.5% by ISCH: (A) ^99mTc stress images with stress contours, (B) coregistered ²⁰¹Tl REST images with stress contours, (C) change counts displayed within the contour (partial-volume effect causes some voxels to be partially outside the contour), and (D) fused display of normalized change counts with stress images.