The roentgenological aspects of empyema

Abstract

OENTGENOLOGIC study is of R vaIue in empyema in two ways. The roentgenoIogist’s cooperation is required in deahng with suspected cases, for the diagnosis of the presence, amount and position of fluid in the pIeural cavity. His assistance, however, is aIso required in estabhshed cases, to observe the progress of the disease, to determine the effects of surgica1 procedures, and to eIucidate factors preventing resohrtion. FIuid in the pIeura1 cavity, except in minutest amount, can aIways be demonstrated by compIete roentgenoIogic examination. The appearances produced are, for the most part, characteristic, especiaIIy when effusion is the onIy Iesion. Some difficuIty may occur in cases with doubIe Iesions, either primary Iung disease with secondary empyema, or more rareIy, primary empyema with secondary Iung or pericardia1 invoIvement. X-ray study aIso permits accurate IocaIization, whether the fluid Iies superficiahy or deepIy. This cannot be achieved with any degree of certainty by physica examination; in cases of deepIy pIaced fluid it is impossibIe. PIeuraI effusions may exist either as free Auid, or may be IocuIated by adhesions, and may therefore be discussed under these two main headings. The effusions associated with cardiac or renaI disease, with rheumatic fever, with earIy mahgnant disease of the Iungs and the uncomphcated effusions occurring in tubercuIosis are a11 simple, non-puruIent effusions or transudates, and do not properIy come under the heading of empyemata. They produce, however, roentgenoIogic appearances aImost identica1 with those produced by the free puruIent effusions. These incIude a proportion of the acute pneumococca1 exudates, and practicahy a11 the acute streptococca1, staphyIococca1 and inff uenza1 exudates in the earlier stages. From the point of view of treatment, it is of great importance to distinguish these free effusions, especiaIIy the streptococca1 type, as it is necessary to wait for IocaIization before instituting any form of radica1 drainage. Free puruIent effusions aIso occur when the simpIe effusions of tubercuIosis, or of mahgnant disease, become infected; or when the pIeura becomes invoIved secondariIy to chronic pyogenic disease of the lungs, such as abscess or bronchiectasis. Pyogenic effusions have a naturaI tendency to Iimitation by adhesions. Such adhesions may exist from the beginning, especiahy in association with pneumonia, or may occur subsequentIy, as the disease develops. Th is causes the formation of IocaIized coIIections of pus, so-caIIed encapsuIated, IocuIated or pocketed empyemata. These may occur in any portion of the pIeura1 cavity as periphera1, mediastinaI, diaphragmatic or interIobar pockets. PIeuraI effusions other than pyogenic, do not show this tendency to IocaIization. It is unnecessary to dweI1 at Iength on the pureIy mechanica detaiIs of the roentgenoIogic technique in the examination of these cases. A brief consideration of the genera1 scheme of the examination of an empyema case is, however, advisabIe. The first roentgenoIogic examination in most chnics is usuaIIy the routine examination of the chest, taking a posteroanterior stereoscopic pair of hIms, with the patient sitting or standing. Tube distance shouId be at Ieast four feet. With a patient who is very III a “bed chest” roentgenogram, with the fiIm under the patient’s back and a short tube distance, wiI1 have to suffice although it is not of the same value. Such routine fiIms wiI1 show the presence of fIuid in any part of the chest, except retrocardiac, or Iow down *Read before the staff meeting of The Lockwood Chic, Toronto, February, 3, 1930.