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Biomedical subjects

G Gamsu

Publications and source records attributed to G Gamsu.

At least 55 records · Page 3Linked to original sources
PubMed1989

Computed tomography in the diagnosis of asbestos-related thoracic disease.

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.

Asbestosis↗
PubMed1989

Magnetic resonance imaging of the thorax: techniques, current applications, and future directions.

Magnetic resonance imaging (MRI) has been used extensively to evaluate the central nervous and musculoskeletal systems. MRI provides excellent contrast between normal and pathologic tissues, identifies vascular structures without the need of intravenous contrast, and is able to image in multiple planes. Until recently, physiologic motion produced artifacts that markedly limited the use of MRI in the thorax. However, with the advent of cardiac gating and respiratory motion compensation, diagnostic images can now be readily acquired. The ability to distinguish between flowing blood and adjacent tissue allows for the detection of aortic aneurysms and dissections. Prominent vessels may be differentiated from hilar adenopathy without the use of contrast agents. Preliminary experience suggests MRI may be useful in assessing central pulmonary emboli and mediastinal venous obstruction. The ready identification of flow combined with the multiplanar capability of MRI provide a means of assessing congenital abnormalities and other anatomic information. Fast scan techniques provide a dynamic means of assessing cardiac function and are sensitive to valvular stenosis and insufficiency. Combined with spin-echo techniques, areas of myocardial infarction and focal wall motion abnormalities can be detected. Currently, MRI has little application in the assessment of pulmonary nodules, bronchogenic cancer, and diffuse parenchymal disease. Sagittal MR images may more clearly show tumor extension into the axilla, brachial plexus, and spinal canal in patients with superior sulcus neoplasms. Future applications may include faster imaging techniques, blood flow measurement, detection of thrombus using phase sensitive techniques, regional perfusion, and assessment of cellular energy metabolism.

Forecasting↗
PubMed1989

Conventional and high resolution computed tomography in the diagnosis of asbestos-related diseases.

High resolution CT (HRCT) can image the fine structures of the lung parenchyma and the pleura. Analysis of supine and prone HRCT scans in 300 patients with asbestos exposure shows that asbestosis is characterized the following findings; (1) parenchymal bands, (2) increased interlobular septa, (3) increased intralobular core structures, (4) subpleural lines, and (5) dependent opacity. Pleural disease is well displayed on HRCT scans. Correlated studies with whole lung sections confirm the HRCT findings. Masses in asbestosis may be benign or malignant, and CT helps in their differentiation. HRCT correlates well with radiographic and clinical criteria for asbestosis and is more sensitive than either in detecting abnormalities.

Asbestosis↗
PubMed1989

Costal pleura: appearances at high-resolution CT.

The appearance of the costal pleura at high-resolution computed tomography (CT) was evaluated with a cadaver and 25 normal subjects. This was contrasted with the high-resolution CT appearance of the costal pleura in 15 patients with mild pleural thickening, 13 of whom had been exposed to asbestos. On high-resolution CT scans in the normal subjects, a 1-2-mm-thick line of soft-tissue attenuation at the point of contact between lung and chest wall represents the visceral and parietal pleura, pleural contents, endothoracic fascia, and innermost intercostal muscle. In a paravertebral location, the innermost intercostal muscle is lacking, and a thin line seen on high-resolution CT scans reflects pleura and endothoracic fascia. Transverse thoracic and subcostal muscles and extrapleural fat pads can be seen as tissue internal to a rib and may be confused with pleural thickening. In 13 of the 15 patients with mild pleural thickening, the 1-3-mm-thick pleura was separable from the underlying normal intercostal muscle by a layer of extrapleural fat. High-resolution CT was more sensitive than CT with 1-cm collimation in depicting this degree of pleural abnormality.

Aged↗
PubMed1989

Sarcoidosis: correlation of pulmonary parenchymal pattern at CT with results of pulmonary function tests.

The appearances of the lungs on radiographs and computed tomographic (CT) scans were correlated with degree of uptake on gallium scans and results of pulmonary function tests (PFTs) in 27 patients with sarcoidosis. CT scans were evaluated both qualitatively and quantitatively. Patients were divided into five categories on the basis of the pattern of abnormality at CT: 1 = normal (n = 4); 2 = segmental air-space disease (n = 4); 3 = spherical (alveolar) masslike opacities (n = 4); 4 = multiple, discrete, small nodules (n = 6); and 5 = distortion of parenchymal structures (fibrotic end-stage sarcoidosis) (n = 9). The percentage of the volume judged to be abnormal (CT grade) was correlated with PFT results for each CT and radiographic category. CT grades were also correlated with gallium scanning results and percentage of lymphocytes recovered from bronchoalveolar lavage (BAL). Patients in CT categories 1 and 2 had normal lung function, those in category 3 had mild functional impairment, and those in categories 4 and 5 showed moderate to severe dysfunction. The overall CT grade correlated well with PFT results expressed as a percentage of the predicted value. In five patients, CT scans showed extensive parenchymal disease not seen on radiographs. CT grades did not correlate with the results of gallium scanning or BAL lymphocytes. The authors conclude that patterns of parenchymal sarcoidosis seen at CT correlate with the PFT results and can be used to indicate respiratory impairment.

Airway Obstruction↗
PubMed1989

High resolution computed tomography and lung function in asbestos-exposed workers with normal chest radiographs.

Asbestos-exposed persons with normal chest radiographs can demonstrate parenchymal abnormalities on high resolution computed tomography (HRCT). We reviewed the HRCT, clinical presentation, and results of pulmonary function tests in 169 asbestos-exposed workers with normal chest radiographs (ILO less than 1/0). The HRCT was normal or near normal in 76 subjects (Group 1), abnormal but indeterminate for asbestosis in 36, and abnormal and suggestive of asbestosis in 57 (Group 2). The indeterminate subjects were excluded from further analysis. The subjects in Groups 1 and 2 were not significantly different in their duration of asbestos exposure, latency, smoking history, or in measurements of airflow obstruction (FEV1/FVC% and %FEV1). Both the vital capacity percent predicted and diffusing capacity percent predicted were significantly lower in the abnormal subjects (Group 2) than in the normal subjects (Group 1) (79.0 versus 86.2, p = 0.005; 78.2 versus 87.1, p = 0.024; independent t test). We conclude that in asbestos-exposed subjects with normal chest radiographs, HRCT can identify a group of subjects with significantly reduced lung function indicative of restrictive lung disease when compared with a group with normal or near-normal HRCT.

Adult↗
PubMed1989

Constrictive pericarditis presenting as pleural effusion of unknown origin.

Despite the known association of pleural effusion with constrictive pericarditis, the presentation of constrictive pericarditis as pleural effusion of unknown origin has, to our knowledge, never been described. After evaluating such a case, we retrospectively analyzed all cases of established constrictive pericarditis seen in this institution in the last six years. The clinical and laboratory features of this cohort of 30 patients are similar to those of other reported series. Pleural effusion was present in 18 (60%) of 30 cases. In six (12%) of the 18 cases, pleural effusion was a major component of the clinical presentation, and in three (10%) of these six cases, the persistence of pleural effusion of unknown origin was the indication for referral to this institution. Analysis of pleural fluid in four cases revealed three exudates and one transudate. We believe this is the first report of unexplained pleural effusion as the presenting manifestation of constrictive pericarditis, and this diagnosis should be added to the list of causes of unexplained pleural effusion.

Adolescent↗
PubMed1988

Asbestos exposure-cigarette smoking interactions among shipyard workers.

We studied the roentgenograms, pulmonary function tests, and physical findings of 294 shipyard workers to evaluate asbestos exposure-cigarette smoking interactions. Roentgenographic parenchymal opacities, decreased pulmonary diffusing capacity for carbon monoxide, decreased flow at low lung volume, rales, and clubbing were each significantly related to the number of years elapsed since first exposure to asbestos and cigarette smoking status when analyzed by logistic regression. A dose-dependent cigarette smoking response that was consistent with synergism was present only for parenchymal opacities and decreased flow at low lung volume. These findings suggest that decreased flow at low lung volume, possibly reflecting peribronchiolar fibrosis, may be a functional corollary to smoking-associated parenchymal roentgenographic opacities among some asbestos-exposed individuals.

Asbestos↗
PubMed1988

The effect of cigarette smoking on the detection of small radiographic opacities in inorganic dust diseases.

Whether cigarette smoking can cause radiographic opacities indistinguishable from those due to pneumoconiosis remains controversial. The situation becomes clearer when one limits the abnormalities to those that can be standardized under the International Labour Office (ILO) classification system. The bulk of the evidence indicates that, using the ILO system, cigarette smoking alone is not associated with radiographic opacities that would be mistaken for pneumoconiosis with sufficient frequency to be of any practical importance. The effects of cigarette smoking, as a cofactor, in conjunction with occupational dust exposure depend on the type of dust. No relationship has been convincingly demonstrated for coal dust or silica. Only with asbestos exposure does there appear to be a significant cigarette smoking-associated increase in the frequency of irregular radiographic opacities. This increase does not appear to translate into a restrictive impairment in pulmonary function. The limited information available indicates that the features of asbestosis on high-resolution computed tomography are not similarly related to cigarette smoking. Additional research is needed to substantiate the relationship between smoking and occupational exposure to dust of many types, and also the possible imaging and pathophysiologic significance of their interactions.

Asbestosis↗
PubMed1988

Normal and diseased isolated lungs: high-resolution CT.

High-resolution computed tomography (CT) scans of 12 isolated, inflated, fresh lungs obtained at autopsy were compared with thin, paper-mounted lung sections obtained at the same levels. In six lungs considered intrinsically normal, high-resolution CT showed normal interlobular septa and pulmonary arteries in the lobular core, but lobular bronchioles were not visible. Edematous fluid resulted in thickening and increased visibility of interlobular septa. In three emphysematous lungs, high-resolution CT accurately demonstrated the degree of emphysema and suggested its centrilobular nature. In two lungs with honeycombing, cysts lined by fibrosis were easily seen on high-resolution CT scans. In less severely involved areas, septal thickening and intralobular fibrosis were seen on high-resolution CT scans, but small (1 mm) cysts were invisible. High-resolution CT was able to demonstrate some features of the normal secondary pulmonary lobule and structural alterations produced by various diseases.

Humans↗
PubMed1988

Asbestos-related pleural and parenchymal fibrosis: detection with high-resolution CT.

Twenty-nine subjects with occupational asbestos exposure and clinical asbestosis were examined with high-resolution computed tomography (HRCT) to determine its sensitivity, relative to that of conventional computed tomography (CT), for detection of benign asbestos-related disease. Thin-section HRCT scans were obtained at five discrete levels through the mid and lower thorax in both prone and supine positions. The same technique was used in 34 age-similar control patients. Parenchymal abnormalities were seen most frequently in the posterior portion of the lung bases in the asbestos-exposed subjects. HRCT prone scans enabled basal structural abnormalities to be reliably distinguished from gravity-related physiologic phenomena in 25 asbestos-exposed subjects. HRCT was more sensitive than CT in detection of both pleural and parenchymal fibrosis. In subjects with clinical asbestosis, HRCT demonstrated parenchymal abnormality in 96%, compared with 83% for CT. Similarly, pleural thickening was shown in 100% of subjects at HRCT, compared with 93% at CT. HRCT could be an important adjunct in the evaluation of asbestos-related pleuroparenchymal fibrosis. An HRCT study including prone scans is a sensitive, reliable means of detecting thoracic abnormalities in asbestos-exposed individuals.

Adult↗
PubMed1988

Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans.

In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances.

Asbestos↗