“…In the United States some workers believe mass radiography to be an effective method for finding cases with good chances of operability and survival (Overholt and Schmidt, 1949;Guiss, 1952;Rigler et al, 1953;Overholt et al, 1955), but other American authors take a rather pessimistic view (Ehler et al, 1954;Boucot and Sokoloff, 1954;McNulty, 1954).…”