Biomedical subjects
Publications and source records attributed to G Gamsu.
Collagen vascular diseases (CVDs) are a group of immunologic diseases that affect connective tissue at various locations throughout the body. The article reviews the variable radiographic findings associated with the common and less common CVDs.
Thin-walled lung cysts can occur in association with advanced pulmonary eosinophilic granuloma and lymphangioleimyomatosis (LAM). In LAM, cysts occur as an isolated abnormality or in association with tuberous sclerosis. The cause of these cysts is unclear, but some investigators have postulated that they result from air trapping. To determine if lung cysts in these two diseases are associated with air trapping, the authors performed dynamic ultrafast high-resolution computed tomography (DUHRCT) during forced expiration in two patients (one with eosinophilic granuloma and one with tuberous sclerosis) with lung cysts and correlated the results with results of pulmonary function tests. DUHRCT demonstrated focal and diffuse air trapping; in some lung regions, a less than normal increase in lung attenuation during forced exhalation was evident. These studies do not allow a conclusion regarding the mechanism of cyst formation in eosinophilic granuloma and LAM-tuberous sclerosis, but they confirm the association between lung cysts and morphologic findings of air trapping.
To determine the prevalence of "nonobstructive" (impairment of gas transfer) emphysema in a select population of smokers with dyspnea, a retrospective study of patients with emphysema evident at high-resolution computed tomography (HRCT) was undertaken. Four hundred seventy HRCT studies were reviewed. In 47 cases, centrilobular emphysema was the dominant or sole parenchymal abnormality. Concomitant chest radiographs were available in 41 of these cases; 16 of the 41 lacked radiographic findings of emphysema. Among these 16 patients, pulmonary function testing revealed 10 to have normal flow rates (ratio of forced expiratory volume in 1 second to forced vital capacity and forced expiratory volume in 1 second greater than 80% predicted) and impaired gas transfer (single-breath carbon monoxide diffusing capacity [DLCOSB] less than 80% predicted). With the exclusion of one patient with congestive heart failure from the group of 10, the severity of emphysema at HRCT correlated inversely with DLCOSB (r = -.643). These results indicate that HRCT allows detection of emphysema in symptomatic patients when chest radiographs and pulmonary function tests are nondiagnostic.
OBJECTIVE: In its subacute or chronic form, hypersensitivity pneumonitis is often difficult to distinguish clinically and physiologically from other idiopathic diffuse lung diseases. The aim of this study was to identify high-resolution CT features that allow distinction of chronic hypersensitivity pneumonitis from other chronic diffuse parenchymal lung diseases. MATERIALS AND METHODS: Six patients with chronic hypersensitivity pneumonitis were examined with pulmonary function testing, bronchoalveolar lavage, lung biopsy, chest radiography, and high-resolution CT. The chest radiographs and high-resolution CT scans were reviewed independently by three observers without knowledge of the patients' clinical status. Discrepancies between the observers were resolved by consensus. RESULTS: The chest radiographs revealed normal lung volumes with a combination of abnormalities: a mixed alveolar/interstitial pattern in five cases, peribronchiolar thickening in three, a diffuse granular pattern in one, and a linear fibrotic pattern in one. In general, the high-resolution CT scans showed more abnormalities than were apparent on the plain chest radiographs. High-resolution CT revealed centrilobular, peribronchiolar, indistinct nodular opacities, of various numbers, in all cases. Four cases had areas of ground-glass density, three cases had lobular areas of hyperlucency, and one case had areas of pulmonary fibrosis and honeycombing. CONCLUSION: We confirm that high-resolution CT can most clearly show the type and distribution of parenchymal abnormalities in patients with hypersensitivity pneumonitis. Importantly, although not pathognomonic, the high-resolution CT finding of centrilobular, peribronchiolar, indistinct nodules should suggest the diagnosis of chronic hypersensitivity pneumonitis.
High-resolution computed tomography (HRCT) was performed in 21 isolated animal lungs, from 4 mammalian species (pigs, rabbits, dogs, sheep). Gross and subgross central and peripheral lung morphology was determined by HRCT. Three distinct types of lungs can be identified, principally based on the extent of interlobular septal development; the relationship of major vessels to airways; and the thickness of the visceral pleura. Type-I lung is found in pigs, sheep, and cattle; type-II lung is found in rabbits, dogs, cats, and monkeys; and type-III lung is found in human beings and horses. These mammalian lungs were compared with human lungs. The potential use of HRCT to investigate specific human lung diseases in the aforementioned species also was considered.
The pathogenesis of pulmonary edema that occurs during interleukin-2 therapy has often been attributed to an increase in pulmonary capillary permeability. However, renal insufficiency, fluid overload, and hypotension also develop in many patients. These manifestations of systemic toxicity may contribute to the development of pulmonary edema during therapy. Understanding the cause of pulmonary edema during interleukin-2 therapy could directly affect patients' care. Therefore, we reviewed the chest radiographs and clinical course of 54 patients who received high-dose interleukin-2 therapy and lymphokine-activated killer cells for advanced carcinoma. The type, frequency, and course over time of pulmonary abnormalities were recorded and correlated with clinical measures of renal function, fluid status, and blood pressure. Focal or diffuse parenchymal lung opacities were found on radiographs in 43 (80%) of 54 patients. Findings of interstitial pulmonary edema were most common, occurring in 76% of patients. Weight gain, hypotension, and elevation of the serum creatinine level were not associated statistically with interstitial edema. Diffuse air-space disease developed in 20% of patients. Focal consolidation, which was associated with positive central venous catheter cultures (p less than .03), developed in 28% of patients. Pleural effusion occurred in 48% of patients and was associated with all types of parenchymal disease. These data suggest that the frequent development of pulmonary edema during interleukin-2 therapy is not due to renal insufficiency, fluid overload, or hypotension, but is more likely the result of an interleukin-2-related increase in pulmonary capillary permeability.
The traditional imaging technique used in the assessment of patients suspected of having silicosis or asbestos-related disease has been the chest radiograph. However, computed tomography and high-resolution computed tomography have become widely available for these assessments. The relative merits of these techniques in the diagnosis of these diseases warrant review.
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A combination of cytotoxic and corticosteroid therapy has dramatically improved the long-term survival of patients with Wegener granulomatosis. With extended survival, patients now experience diverse cardiopulmonary abnormalities that represent primary or secondary manifestations of the disease or that result from diagnosis and treatment. To evaluate these abnormalities, the authors reviewed the medical histories and chest radiologic findings of 19 patients with the histologic diagnosis of Wegener granulomatosis. In these patients thoracic images demonstrated parenchymal nodules or consolidations with cavitation, diffuse interstitial disease, mediastinal or hilar adenopathy, and isolated stenoses of the larynx or tracheobronchial tree. Intrathoracic relapse occurred in 18 cases; in one-third of these patients, findings at relapse differed from those at initial presentation. Complications from diagnosis or therapy occurred in nine patients. Pulmonary infection was the most frequent complication causing morbidity and was often clinically indistinguishable from the primary disease; it complicated relapse in five patients. The successful radiologic follow-up of patients with Wegener granulomatosis requires a consideration of the varied thoracic manifestations of both the primary disease and the complications of its treatment.
The radiographic distribution of Pneumocystis carinii pneumonia was studied in 64 consecutive patients with acquired immunodeficiency syndrome to determine the demographic and clinical factors that might be associated with predominance of the disease in the upper zones of the lungs. Twenty-three patients were receiving monthly prophylaxis with 300 mg of aerosolized pentamidine by means of inhalation; the other 41 were not receiving pentamidine and served as a control group. Parenchymal abnormalities were present in 63 of 64 patients. Pleural effusion and cystic lung lesions were uncommon and did not differ between the two groups. Patients receiving aerosolized pentamidine were more likely than control patients to have disease isolated or predominant in the upper lobes (odds ratio = 3.9, confidence interval = 1.1-14.1). After the possible effects of confounding variables were taken into account, prophylaxis remained a significant risk factor. Age and a previous history of P carinii pneumonia were not significant cofactors. The pattern of deposition or retention of the aerosolized pentamidine could be responsible for the finding of predominant P carinii pneumonia in the upper lobes of the lungs.
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High-resolution computed tomography (HRCT) has improved the radiologist's ability to detect and potentially quantify the abnormalities of asbestos exposure. It has proved to be more sensitive than chest radiography for detecting pleural plaques and for discriminating between pleural fibrosis and extrapleural fat. HRCT is also more sensitive than chest radiography or conventional CT for detecting parenchymal abnormalities in asbestos-exposed persons. The HRCT findings that correlate with other parameters of asbestosis include (1) septal and centrilobular thickening, (2) parenchymal fibrous bands, (3) honeycomb patterns, (4) subpleural density persisting in the prone position, and (5) subpleural curvilinear lines that persist in the prone position. CT has an important role in evaluating benign and malignant lung and pleural masses in asbestosis.