摘要:

Distribution of pulmonary vascularity, as imaged on the routine chest radiograph, may be used as an accurate and sensitive indicator of underlying pathophysiologic change. The lungs, like most other human organ systems, have extensive reserve capability. Such reserves exist in terms of excess alveolar capacity in the pulmonary vascular bed to compensate for certain vascular alterations. This available vascular reserve is potentially available to compensate for situations in which there is an imbalance created between the size (capacity) of the vascular bed and the amount of blood (content) that it must accommodate. Such imbalances can result from decrease in the size of the vascular bed secondary to destruction or to normal physiologic response mechanisms or from an increase in the amount of blood coursing through the vascular bed. Either occurrence or combination of occurrences necessitates recruitment of available pulmonary vascular reserves. Recognition of this recruitment phenomenon and understanding of its underlying pathophysiologic significance enable relatively sophisticated diagnostic interpretation of the chest radiograph.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Positron emission tomography and appropriately labeled, short-lived radiopharmaceuticals can be used to study a variety of physiologic processes within the lung. Recently, methods have been developed to measure regional pulmonary blood flow and pulmonary vascular permeability to protein macromolecules. The advantages of these techniques include accurate quantitation, regional data available in an image format, noninvasiveness, and repeatability. These methods have recently been applied to studies of hypoxic vasoconstriction, pulmonary edema, and chronic obstructive lung disease in man and large experimental animals. Although the technology is complex and requires the integration of people from a variety of disciplines, these methods offer a unique opportunity to study in vivo lung physiology.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Elevation of pulmonary arterial pressure may be secondary to many diseases of the lungs, chest wall, and heart. From a pathophysiologic viewpoint, pulmonary hypertension is secondary to vascular obstruction, vasoactivity, increased circulation, and passive forces. Clinically, the entities that result in secondary pulmonary hypertension present with a picture that identifies the primary disease. Patients with primary pulmonary hypertension may be difficult to identify. Pulmonary hypertension may present early with dyspnea and fatigue, while syncope and hemoptysis are late symptoms. In many instances, pulmonary hypertension can be diagnosed utilizing physical examination and noninvasive tests. Eventually, right heart catheterization is necessary to confirm the diagnosis and to monitor trials of therapy with vasodilators. Treatment may be specific (closure of a septal defect, thromboendarterectomy) or generic (vasodilators). These have been used recently for both secondary and primary pulmonary hypertension in an effort to reduce pulmonary vascular resistance, thereby decreasing right ventricular afterload and improving cardiac output and oxygen delivery. The success of these treatments has not been demonstrated.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Pulmonary vasculitis occurs most commonly in the collagen vascular diseases and in granulomatous pulmonary disease. In the collagen vascular group, vasculitis causes diffuse interstitial inflammation and subsequent fibrosis, resulting in interstitial radiographic patterns, especially in the lower lung fields. Vasculitis accompanied by granulomatosis typically produces focal inflammation and is, therefore, manifested as nodules and masses. The more typical collagen vascular diseases include rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and dermatomyositis. The most common vasculitis granulomatosis is Wegener's, with similar radiographic abnormalities occurring in lymphomatoid granulomatosis. Atypical examples of vasculitis pulmonary disease include ankylosing spondylitis, in which upper-lung field fibrobullous changes are seen. Periarteritis nodosa and Behcet's syndrome include abnormalities of large vessels and thromboembolic phenomena. Bronchocentric granulomatosis and allergic granulomatosis involve airway abnormalities as well as vasculitis and granuloma formation.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

There has been no noninvasive, readily available method for clinically evaluating changes in pulmonary metabolism of biogenic aminelike substances. Such metabolic changes, which almost surely take place on the surface or within the endothelial cells that line the pulmonary vasculature, are likely to be significant components of the overall clinical response of the lung to many disorders. Radioiodinated metaiodobenzyl-guanidine (MIBG) shows properties in isolated, perfused lung preparations that simulate those of biogenic amines (eg, its uptake is sodium-dependent and virtually abolished by ouabain). New data from studies in sheep and humans indicate that changes in first transit pulmonary extraction of this compound can easily be monitored externally using conventional gamma camera-computer systems. MIBG labeled with iodine 123 may provide an important new means for clinical assessment of changes in pulmonary endothelial metabolism.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Bronchial atresia is a rare anomaly that characteristically presents with a pulmonary nodule and hyperinflation of the lung distal to the nodule. To make this diagnosis definitively, invasive studies have been required. Now with the combined use of computed tomography and magnetic resonance imaging, a diagnosis can be made without resorting to invasive techniques. This article describes a case of bronchial atresia illustrating the noninvasive approach.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

A rare case of a combination of an accessory cardiac bronchus and a right tracheal bronchus found incidentally is presented, together with a discussion of the anatomy, embryology, and possible clinical ramifications of these anomalies. The incidence of these anomalies occurring in 2,000 tomographic studies of the chest at University of South Alabama Medical Center is cited.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Computed tomographic and pathologic correlations of the thymus gland were assessed in 69 patients. The sensitivity of computed tomography (CT) for undifferentiated thymic pathology is 87.1%; the specificity is 85.7%. The sensitivity of CT for neoplasm or mass is 97.1%, the specificity is 97.1%. The sensitivity of CT for lymphoid follicular hyperplasia (LFH) is 71.4%, the specificity is 97.6%. Therefore, a normal-sized thymus gland on CT does not exclude LFH. Completely preserved fat planes between thymic mass and adjacent structures on CT usually indicate a benign (noninvasive) neoplasm; completely absent fat planes usually indicate a malignant (invasive) neoplasm; partially preserved fat planes are indeterminate in assessing invasiveness. CT is also useful in showing recurrence or remnants of thymic tissue in patients who have had a previous thymectomy.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

In reviewing the medical records of ten patients with Lennert's lymphoma, we found chest radiographic abnormalities in five cases. Two cases had hilar and mediastinal adenopathy without associated parenchymal or pleural disease, and three cases had isolated pulmonary parenchymal abnormalities. In one patient, both the chest radiograph and the histologic findings, obtained by open lung biopsy, mimicked miliary granulomatous disease. This article emphasizes the need to be alert to this aggressive T-cell neoplasm, since its clinical course differs significantly from some of the diseases it tends to imitate. By being aware of the entity and by using thorough pathologic and immunopathologic techniques, difficult cases of Lennert's lymphoma can be successfully diagnosed.

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID

ISSN:0883-5993    

出版商:OVID    

年代:1988

数据来源: OVID