An apparatus for obtaining a long-length x-ray image of a subject, has an x-ray source and a first sensor that generates a first signal that indicates termination of x-ray emission from the x-ray source. A digital radiography detector is energizable to generate image data after receiving x-ray emission from the x-ray source. A detector transport apparatus is actuable in accordance with the first signal to translate the digital radiography detector from at least a first detector position to a second detector position for generating image data at each detector position. A processor in communication with the digital radiography detector obtains the image data of the subject that is generated from the detector.