We have developed a scanned projection x-ray imaging system in which a 1 to 2 cm slot beam of radiation is used to acquire 96 image lines simultaneously, thereby reducing scatter, x-ray tube heat loading and image aquisition time. This system is designed for quantitative angiography, but the TDI technique we describe is equally applicable to other radiographic procedures such as mammography. Our system utilizes an x-ray image intensifier and a charge-coupled device operating in the time-delay-integration mode. The slot beam may be scanned to create an image in a few seconds or remain stationary in order to perform quantitative analysis of arterial flow. In this paper we describe our system, report on our investigations of imaging performance and present examples of radiographic images. We have found that the noise in our charge-coupled device camera may be reduced to about 270 noise equivalent carriers by cooling the detector, giving a dynamic range greater than 2000. The limiting spatial frequency for the system is 1.7 mm-1, restricted primarily by the performance of the x-ray image intensifier.