Roentgenological Exploration of the Bronchial Tubes with Iodized Oil (Lipiodol)

THE use of a new means of contrast for radiological exploration has been, in every case, in correspondence, in some respects, with practical improvements: for example, the opaque solutions of sodium bromide have been helpful towards a better knowledge of the pathology of the kidney pelvis and ureters, and the discovery of pneumoperitoneum for radio-diagnostic purposes has increased our findings in pathology of the abdominal organs. Four years ago we began methodically to use as an opaque fluid for radiology an iodized oil (lipiodol) which French and foreign physicians had been injecting for many years in cases where a chronic iodine treatment was to be carried out. In fact, many physicians had noticed that this oil, being injected subcutaneously or intramuscularly, gave, in radiograms, large opaque spots, which remained visible for a long time, though no clinical symptom of the presence of the oil could be observed. The original part of our work was to take advantage of the qualities of lipiodol—high opacity to X-rays and perfect tolerance by human tissues—and to use it as a means of contrast for the radiologic exploration of cavities which it had been impossible to explore with methods previously in use. Our first experiments were made on the cavities of the spine, epidural and subarachnoid spaces, but soon after, realizing the wonderful innocuity of lipiodol, we found that it would be well tolerated by the respiratory mucous membrane and could be introduced by intra-tracheal injections. Our first attempts on animals (rabbits and guinea pigs) proved to us that lipiodol could be injected into the bronchial tubes without more danger than any ordinary oil. In January, 1922, with our friend L. Le-roux, we succeeded in getting the first film of the bronchial tubes of a living subject, a film which, for the first time, was purposely and harmlessly obtained. Before describing the technic and results of the method, we shall say a few words about the drug itself. Lipiodol Lipiodol is vegetable iodized oil, containing 40 per cent of iodine, this high percentage explaining the favorable opacity of the substance to X-rays. It is important to note that lipiodol is not a solution of iodine in vegetable oil, but a definite chemical compound in which the halogen cannot be detected by ordinary reactives. This explains why, in spite of its high concentration in iodine, lipiodol is so wonderfully tolerated in the cavities of the body; as there is no iodine free in lipiodol, this one does not produce any irritation or toxicity, as any iodine solution is expected to do. Lipiodol is a fine, pure, transparent oil, a little darker in color and much thicker than olive oil.