Renal digital imaging has progressed rapidly in reliability and potential since its clinical introduction in 1979. The advent of larger image intensifiers has made feasible subtraction imaging of the renal parenchyma and collecting systems as an adjunct to IV-DSA. The growing use of IA-DSA has expanded the utility of the technology to the examination of the intrarenal circulation, contrast-sensitive patients, and the performance of interventional procedures. There are experimental works suggesting that it may be feasible to derive accurate physiologic data reflecting renal blood flow and excretion from sequential alterations in intravascular contrast density. Thus, anatomic abnormalities and their significance might conceivably be determined, with minimal patient discomfort, from the same imaging procedure. The development of digital imaging technology and techniques continues to be of major interest to both academic and commercial investigators. Thus, further improvements in digital imaging and expansion of its capabilities are likely to occur.