Semiautomated renal region-of-interest selection method: validation in a dog model.

A successful method of automated region-of-interest (ROI) selection by polar edge search for use in technetium-99m-diethylenetriaminepentacetate (99mTc-DTPA) renography is presented in a dog model. The accuracy of the resultant ROI was tested by comparing renal uptake within the ROI to simultaneously monitored arterial 99mTc-DTPA concentration. The automatically selected ROI resulted in renal uptake curves that better matched arterial clearance than either systematically larger and smaller ROIs or a manually chosen ROI.