A significant advance in knowledge of tuberculosis has come from recognition of the occurrence of grave, often progressive, disease that has not undermined health, has produced no evident symptoms and is unassociated with physical signs demonstrable by the usual methods of physical examination. Nevertheless, the fundamental importance of this latent tuberculosis as a forerunner of clinically manifest disease is not universally accepted. Many clinicians have been unwilling to admit that progressive tuberculous lesions are evident in roentgenographic films before the disease has produced any symptoms or physical signs. Roentgenographic examination often reveals the anatomic characters of tuberculous lesions before they have produced any functional disturbances demonstrable by existing methods. Progress in the early diagnosis of pulmonary tuberculosis by means of procedures available today is chiefly dependent on wider recognition of the value of technically adequate roentgenographic examination of the chest.
Some clinicians and roentgenologists find it difficult to separate latent