*These calculations should look familiar, as they are identical to the equations used to determing left ventricle ejection fraction. Let's look at an example. Calculate the GBEF from the following data. GB maximum 254,000 counts in 241 pixels Bkgd maximum = 11,000 counts in 125 pixels GB minimum = 92,000 counts in 84 pixels Bkgd minimum = 3,000 counts in 62 pixels First, determine net maximum counts: Next, determine net minimum counts: Finally, determine the GBEF: Calculate the GBEF for each set of data. 1. net maximum counts = 235,000 counts net minimum counts = 174,000 counts 2. net maximum counts = 97,290 counts net minimum counts = 73,180 counts 3. net maximum counts = 312,500 counts net minimum counts 187,300 counts 4. net maximum counts = 235,000 counts net minimum counts = 174,000 counts 5. maximum GB counts = 268,000 counts in 269 pixels maximum bkgd counts = 14,000 counts in 191 pixels minimum GB counts = 193,000 counts in 186 pixels minimum bkgd counts = 4,100 counts in 102 pixels 6. maximum GB counts = 224,000 counts in 487 pixels maximum bkgd counts = 12,400 counts in 142 pixels minimum GB counts = 117,000 counts in 193 pixels minimum bkgd counts = 2,430 counts in 57 pixels