Both CR and DDA were originally developed exclusively for medical radiology. Medical CR was initiated in the early 1980s while DDA use began in the late 1990s. These modalities have basically eliminated the utilization of film in the modern medical, dental and veterinary industries. During the 1990s, CR was the first method to be utilized for industrial nondestructive testing (NDT). ASTM has facilitated the growth of these digital techniques with the establishment of various standards that offer standard practices and guides that provide standardization within both the industrial and aerospace industries. The primary NDT qualification and certification documents, SNT-TC-1A and NAS 410, were revised in 2011 and 2014 respectively to detail additional training and experience that would enable personnel certification in digital radiography.