Bedros Markarian

Pulmonary Thromboembolic Disease: A Lobular Concept

Infarcts are aggregates of infarcted secondary pulmonary lobules. Infarction of a single lobule can occur. Application of a lobular concept of thromboembolic d1sease provides a morphologic basis which partly explains the limitations inherent in plain film diagnosis. Infarcts have no predictable configuration. Thromboembolism may cause hemorrhage indistinguishable radiographically from pneumonia or edema. When the infarct is surrounded by hemorrhage, when there is admixture of infarcted and viable lobules at the infarct margin, and when interface between infarcted and viable lobules is not parallel to the x-ray beam, the poorly defined infarct outlines may make differentiation from pneumonia or edema impossible.

The Secondary Pulmonary Lobule: A Practical Concept for Interpretation of Chest Radiographs

A thorough understanding of normal roentgen anatomy forms the basis for the interpretation of any radiograph. The radiologist commonly visualizes the anatomy of the lung in terms of lobes, segments, or subsegments; rarely does he consider pulmonary structure in terms of smaller anatomic units. This is true despite the fact that the work of William Snow Miller (9) in the early part of this century established the secondary pulmonary lobule as the basic unit of lung structure and function. Although the anatomic study of the secondary pulmonary lobule has continued for over half a century, relatively little consideration has been given to its roentgen appearance and significance. The purpose of this paper is to unify past concepts of the anatomy of the secondary pulmonary lobule and to clarify the role which the secondary pulmonary lobule plays in the normal roentgen appearance of the lung. Some controversy has arisen regarding the basic unit of lung structure, due to the use of such terms as the primary pul...

Traumatic rupture of the thoracic aorta. Roentgen-pathological correlations.

Abstract Although death follows immediately in about 80 per cent of all cases of traumatic rupture of the aorta, 20 per cent of the patients survive to undergo diagnosis and treatment. The prognosis is favorable after treatment, but the diagnosis may be difficult. The gross and microscopic pathology of aortic rupture is reviewed and the findings discussed. It is likely that some cases of Erdheims cystic medionecrosis of the aorta may be the result of trauma.

The Apical Cap

Nonspecific thickening of the apical visceral pleura and subpleural lung associated with fibrosis and sometimes with calcification, was found in 20.3% of cases. This thickening could not be shown histologically to be the result of tuberculosis. The frequency of such scarring increased significantly with age. Such localized pleural thickening may be related to healing of pulmonary disease in the presence of chronic ischemia. This subpleural scarring appears to be the cause of the apical cap shadow reported by many authors; other possibilities include (a) irregular projection of the lung into the overlying soft tissues and (b) other apical pulmonary disease.

Pseudomonas Pneumonia: A Prototype of Hospital-Based infection

The authors studied 23 proved cases of Pseudomonas pneumonia; there were pathologic, anatomic, and roentgen correlations in 10 cases. Radiographic findings were (a) varying degrees of patchy bronchopneumonia which included a nodular appearance often seen early in aspirational or septicemic pneumonia; (b) large excavating abscesses and pathologic microabscesses; (c) an occasional interstitial appearance; (d) smaller pleural effusions or areas of thickening which were common but not prominent; (e) occasional pneumatocele formation with possible pneumothorax. Pseudomonas chest infection may be part of a continuing pattern of abnormal pulmonary densities produced by pneumonia with changing etiologic agents.