of an exceedingly definite character, apparently permitting conclusive interpretations, the radiograph revealed a surprising divergence from the clinical findings. The lack of correspondence between the results of the physical and x-ray examinations related particularly to the

Fig. 55. Posterior view. Moderate tuberculous infiltration of both apices. Cavity size of egg at right apex. Well-defined thickening of mediastinal pleura extending above clavicles, with greatest breadth at level of clavicle. Tuberculous gland at junction of sixth rib with vertebra, as indicated by arrow. Heart small, partially obscured, and displaced upward.

determination of the size and position of the heart, the diagnosis of pulmonary cavities, and the detection of bronchial glands.

Slight and even moderate cardiac displacement from the traction. incident to fibrous tissue proliferation was found in several cases, when such condition was not suggested upon physical examination. This was especially true of upward displacement resulting from marked.

fibrosis of the mediastinal pleura. It is well understood that certain difficulties in the way of accurate physical diagnosis are incident to the anatomic location of a considerable portion of the heart beneath and to the right of the sternum, and to its frequent denudation upon

Fig. 56.-Posterior view. Extensive tuberculous involvement of right base, with connectivetissue contractile change. Note height to which diaphragm ascends on right side, as compared with left. Slight involvement of right apex. Slight tuberculous infiltration, left upper lung. Note circumscribed area simulating cavity. Heart small, partially obscured, and displaced to right. Compare with Fig. 102.

the left side by pulmonary shrinkage. This often increases the area of cardiac dulness in tuberculous patients to a very material extent. Several times I have experienced the utmost difficulty without the aid of the x-ray in determining with precision between a displaced and a dilated or hypertrophied organ. The obstacles in the way of a correct

Fig. 58.-Posterior view. Pronounced thickening of mediastinal pleura, with infiltration of right apex. Physical signs strongly suggestive of pulmonary cavity. Second and third ribs on the right previously resected in order to permit collapse of cavity. No cavity discoverable in picture. Com pare with Fig. 169.

differentiation between simple displacement, among consumptives, and changes in size incident to adherent pericardium and other causes, are enhanced by the morbid pulmonary change sometimes present in immediate contiguity to the heart itself, often obscuring the results

Fig. 59. Posterior view. Well-marked infiltration of right lung, particularly pronounced at the root. Also infiltration of the left lung at the same level, with marked thickening above the base of the heart.

of percussion. In such cases the use of the x-ray has been shown to be of inestimable value as an aid to diagnosis. Short exposures are necessary for the accurate study of the heart, otherwise, on account of the cardiac pulsation, there is lost a sharp definition of outline. Very short exposures of from one-half to one-fifth of a second, however, are

rarely attended by satisfactory results, save in little children or much emaciated adults. Perfect sharpness of outline is not indispensable in the determination of the size and position of the heart. Moderately long exposures of from five to twenty seconds in duration, while pro

Fig. 60.-Posterior view. Well-defined tuberculous infiltration, both apices, more marked on the left. Pronounced thickening, mediastinal pleura and peribronchial infiltration. Also thickening of left base. Physical signs show moisture left side, apex to base.

ducing a less clear definition of the cardiac boundary, are occasionally required, especially in well-nourished individuals and in those of considerable muscular development. A hazy outline similar to that of a composite photograph is sometimes unavoidable in skiagraphs of