The Advantages of the Standard Stereoscopic Examination of the Lungs with 14 by 17 Inch Films in the Diagnosis of Pulmonary Tuberculosis

Abstract

To all who are familiar with the capabilities of the standard roentgenographic examination of the lungs in disclosing or excluding the presence of early pulmonary tuberculosis, it seems needless to discuss the value of the method, for the extraordinary efficiency of this technic has been proved beyond all reasonable doubt. Indeed, it may confidently be asserted that few, if any, medical tests excel this procedure in reliability. The anatomic conditions favor accurate results, for any tuberculous lesions that on section could be seen with the unaided eye must produce visible shadows against the transradiant normal parenchyma. Visible depiction of the lesions is favored also by the slight magnification of their shadows beyond actual size and by the stereoscopic view, which latter factor practically insures against their concealment by shadows of the thoracic cage, shows their precise situation and distinguishes them from shadows due to extrapulmonic causes. By reason of these fortuitous factors, roentgenologic examination often will disclose minimal tuberculosis when symptoms, physical signs and results of laboratory tests are indecisive or even negative. Phthisiologists are keenly aware of this fact, and Sampson and Brown have said: Today we have progressed to the stage where we call no man sound pulmonically until his stereoscopic roentgenograms have been found to be normal, and consider the roentgenologic study as much a part of the routine examination of the lungs as the stethoscope, or, indeed, as the examination of the sputum. Like other roentgenologic technics, the standard stereoscopic examination with 14 by 17 inch films did not suddenly attain its present form or efficiency, but acquired both by slow development. At first, roentgenoscopic examination was considered sufficient. Then