National Geographic : 1987 Jan
PET/SPECT In the doughnut hole ofa PET scanner, a, patient (below): squeezes a hand grip that Helps stimulate the heart during a stress. test. The PET scanner, at the University of Texas in Houston, images trace . amounts of radioisotopes in the heart to determine whether, or no t muscle tissues are receivinga normal supply of blood. Electrodes on the UNIVERSITYor TEXASMEDICALSCHOOL,HOUSTON(ABOVEAND BELOW) 4 M'