The effect of increasing the collimator length on the MDTV for ¹¹¹In, , and ¹³¹I. The T:B was fixed at 5, the background activity concentration was fixed at 5 kBq/ml, the lowest energy-window threshold was applied for each radionuclide, while the collimator length was increased from 0 to 3 cm in increments of 0.5 cm. The error bars in this plot were calculated by summing in quadrature the Poisson noise in the sensitivity map measurements and the variation in the volume of blood within breast tissue [31].