• Part 7: Technologic Progress of the Late 1940s

  • After the end of World War II, technology that had been developed for the military was applied to peacetime endeavors, such as healthcare. Radiology, being an instrumentation-based medical specialty, was greatly affected by the subsequent technologic progress of the late 1940s.

    X-rays for Therapy 

    The first sign of the coming advances in radiology appeared at the 32nd annual meeting of the RSNA in 1946. The RSNA Scientific Assembly was held in early December at Chicago's Palmer House hotel and was a return to the traditional 5-day program that had been disrupted over the previous 3 years by the war. However, in a departure from the usual opening-day meeting events, RSNA President Lowell S. Goin, MD, oversaw a presentation of papers that resulted from the Plutonium Project, a wartime effort that had elevated the importance of radioisotopes to treat, rather than diagnose, disease. This special meeting presentation was the beginning of a division in radiology between diagnosis and therapy.

    Also, work on x-ray image intensification with television was progressing. Before the war, W. Edward Chamberlain, MD, had given an RSNA Carman Lecture in which he stated that fluoroscopic screen views were of poor quality because they were 30,000 times dimmer than the brightness of an abdominal radiograph seen on a view box. After the war, R. H. Morgan, MD, who had created the phototimer, subsequently combined electronic image-intensifier tubes with television equipment and created an automatic brightness control, freeing radiologists from having to readjust intensifier systems during fluoroscopy.

    Additionally, interventional radiology began to develop after publication of an important paper by Merrill C. Sosman, MD, titled "Venous Catheterization of the Heart," in Radiology(1). This article was based on a 1929 discovery by German physician Werner Forssmann, largely overlooked during the war, which showed that a catheter could be safely inserted into the heart (2).

    Benefits of Radiology Recognized 

    By 1947, the National Tuberculosis Association recognized the benefits of chest radiology and, with the approval of the RSNA, then led by President Frederick W. O'Brien, MD, began a campaign urging Americans to undergo periodic checkups, which included "chest x-rays." However, the end of World War II had also ushered in an age in which the public, justifiably fearing the lethal destruction caused by atomic bombs, also became apprehensive about radiation-based medicine. In particular, many individuals were wary of a new subspecialty of radiology, called "nuclear" medicine, that dealt with the same radioactive materials used to construct atomic bombs.

    Consequently, the U.S. Public Health Service set out to reduce radiation exposure from diagnostic x-ray procedures. As the decade progressed, the quality of portable radiographic machinery improved. Delineators, called "collimators," were added to dental x-ray machines so the x-rays were sharply focused and would not irradiate a patient's head and neck, including the thyroid gland. Also, the military development of sonar was transferred to medical use, resulting in ultrasound as a way to visualize anatomy by using sound waves instead of radiation.

    Rise of Physicists 

    In response to the public's growing fear of radiation, the RSNA Standardization Committee, chaired by Lauriston S. Taylor, DSc, recommended standardization and protection programs that could be adopted by the National Bureau of Standards. Additionally, the committee developed a list of physicists deemed qualified to calibrate x-ray machines. In 1947, however, paralleling the Inter-Society Committee agreements finalized in Atlantic City before the war, the RSNA and the American College of Radiology (ACR) decided that the ACR units committee would be "the action body" for matters relating to units, standards, and protection. The RSNA Standardization Committee would oversee education and be a forum for problems in radiologic physics (3).

    In 1948, the RSNA, headed by President L. Henry Garland, MD, subsequently replaced the Standardization Committee with a physics committee, naming Dr Taylor as its chairman. The committee members developed a separate physics program that ran in parallel with the presentations of medical radiology papers at the RSNA annual meetings. They also scheduled physics-based Refresher Courses. Yet perhaps the most important decision they made was to allow full RSNA membership for medical physicists, excluding the ability to be president or chairman of the Society's Executive Board.

    Streamlining the Annual Meeting 

    Due, in part, to the admission of physicists, RSNA membership reached 1,960 in 1949 under the presidency of Edgar P. McNamee, MD. Because of the growth in the scientific program and the increase in membership, the 1949 annual meeting was split between Cleveland's Hotel Statler and the Cleveland Public Auditorium a few blocks away. The Executive Committee members began to realize that the annual gathering was becoming so large it could be held in only a few cities comfortably. The RSNA meeting never returned to Cleveland.

    In fact, the meeting had grown so much that 1950 RSNA President Warren W. Furey, MD, and Donald S. Childs, MD, beginning his third decade as RSNA secretary-treasurer, decided to streamline the scientific program. Paper presentations were grouped into large blocks of Scientific Sessions. In addition, the presentations were limited to 20 minutes, with an opening discussion of 10 minutes and succeeding discussions of 5 minutes, thus paving the way for future Scientific Assemblies.


    1. Sosman MC. Venous catheterization of the heart. Radiology 1947; 48:441.
    2. Grigg ERN, Bagshaw MA, Chamberlain WE, et al. RSNA historic symposium on American radiology: then and now. Radiology 1971; 100:1B26.
    3. Taylor LS. X-ray measurements and protection: 1913B1964. Washington, DC: National Bureau of Standards Special Publication 625, 1981.
    Frederick W. O'Brien, MD President 1947
    left: Lauriston S. Taylor, DSc right: L. Henry Garland, MD