Normalized residual activity: usual values and robustness of the method.

The objectives of this study were 2-fold: first, to investigate the robustness of the normalized residual activity (NORA), a parameter that has recently been proposed for the estimation of renal emptying during renography; and second, to define the usual values of NORA in 2 categories of kidneys-those with a normal renogram and those that are dilated but definitely unobstructed.NORA was defined as the renal activity at a given moment (end of...