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Biomedical subjects

G Gamsu

Publications and source records attributed to G Gamsu.

At least 37 records · Page 2Linked to original sources
PubMed1993

Diagnostic value of chest radiography for pericardial effusion.

OBJECTIVES: This study was designed to determine the diagnostic value of chest radiography for pericardial effusion. BACKGROUND: Pericardial effusions may cause life-threatening cardiac complications, yet they are often difficult to diagnose. METHODS: In a blinded manner, we reviewed the chest radiographs of 83 patients with echocardiographically diagnosed pericardial effusions (5 large, 18 moderate, 60 small) and those of 17 control subjects without effusions. We examined four radiographic signs: an enlarged cardiac silhouette, a pericardial fat stripe, a predominant left-sided pleural effusion and an increase in transverse cardiac diameter compared with the diameter on a previous chest radiograph. RESULTS: An enlarged cardiac silhouette was moderately sensitive (71%) but not specific (41%) for pericardial effusion. A pericardial fat stripe, a predominant left-sided pleural effusion and an increase in transverse cardiac diameter were all specific (94%, 100% and 80%, respectively) but not sensitive (12%, 20% and 46%, respectively). A predominant left-sided pleural effusion was associated with pericardial effusions of all sizes (odds ratio = 1.3, 95% confidence interval [CI] = 1.0-1.6, p = 0.04) and with large and moderate pericardial effusions alone (odds ratio = 7.7, 95% CI = 2.5-24.0, p = 0.0004). In contrast, a pericardial fat stripe was associated only with large and moderate pericardial effusions (odds ratio = 3.3, 95% CI = 0.9-12.0, p = 0.07), and an enlarged cardiac silhouette and an increase in cardiac diameter were not associated with pericardial effusion at all. CONCLUSIONS: A predominant left-sided pleural effusion and a pericardial fat stripe are chest radiographic signs that are suggestive, but not diagnostic, of pericardial effusion. Because these signs cannot reliably confirm or exclude the presence of pericardial effusion, we conclude that chest radiography is poorly diagnostic of this condition.

Analysis of Variance↗
PubMed1993

Dynamic pulmonary CT: findings in healthy adult men.

The authors examined 10 healthy male subjects with dynamic computed tomography to determine normal dynamic and expiratory findings. In both the supine and prone positions, the average increase in lung attenuation during exhalation was found to be significantly greater in dependent lung regions than in nondependent lung regions. In each of the lung zones studied, there was a significant correlation between the decrease in cross-sectional lung area during exhalation and the increase in lung attenuation. At the lung bases, a greater increase in lung attenuation was noted during exhalation for a given change in cross-sectional lung area than in the upper lungs. All 10 subjects showed a distinct lobar attenuation gradient in the supine position. In general, lung attenuation increased homogeneously during exhalation, but four of the 10 subjects showed regions of inhomogeneity in lung attenuation during rapid exhalation indicative of air trapping, despite normal results on pulmonary function tests.

Adult↗
PubMed1993

Normal trachea during forced expiration: dynamic CT measurements.

The purpose of this study was to define the range of normal intrathoracic tracheal diameters and cross-sectional areas during forced respiration. A report of tracheomalacia is also presented. Ten volunteers were studied in the supine position with dynamic computed tomography (CT), at a level at or between the brachiocephalic vein and the aortic arch, with 3-mm collimation and with image reconstruction by means of a high-spatial-frequency algorithm. Ten 100-msec dynamic scans were obtained at 500-msec intervals during a 6-second period as the patient performed forced inspiration and expiration vital capacity maneuvers. The mean cross-sectional area of the trachea decreased dynamically from 280 mm2 at end inspiration (standard deviation, 50.5; range, 221-388 mm2) to 178 mm2 at end expiration (standard deviation, 40.2; range, 115-236 mm2; P < .001) (mean decrease, 35% between inspiration and expiration; standard deviation, 18%; range, 11%-61%). The percentage decrease in cross-sectional area of the trachea correlates well with the decrease in the anteroposterior and coronal diameters of the trachea from maximum inspiration to maximum expiration (r = .879 and .916 and P = .0018 and .0002, respectively).

Adult↗
PubMed1993

CT gantry tilt: utility in transthoracic fine-needle aspiration biopsy. Work in progress.

The authors used a gantry tilt of 20 degrees in five patients to allow fine-needle aspiration biopsy of peripheral pulmonary lesions that were difficult to approach with a vertical alignment because of overlying ribs. This method allowed a direct approach to the lesion in all five cases, with the entire needle path visible in the scanning plane, avoidance of vital structures, and traversal of a minimal amount of normal lung parenchyma.

Adult↗
PubMed1992

Cystic lung disease associated with eosinophilic granuloma and tuberous sclerosis: air trapping at dynamic ultrafast high-resolution CT.

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.

Adult↗
PubMed1992

High-resolution CT diagnosis of emphysema in symptomatic patients with normal chest radiographs and isolated low diffusing capacity.

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.

Female↗
PubMed1992

Chronic hypersensitivity pneumonitis: use of CT in diagnosis.

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.

Alveolitis, Extrinsic Allergic↗
PubMed1992

High-resolution computed tomography of the mammalian lung.

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.

Animals↗
PubMed1991

Pathogenesis of pulmonary edema during interleukin-2 therapy: correlation of chest radiographic and clinical findings in 54 patients.

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.

Adult↗
PubMed1991

Computed tomography and high-resolution computed tomography of pneumoconioses.

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.

Asbestosis↗
PubMed1990

Thoracic manifestations of Wegener granulomatosis: diagnosis and course.

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.

Adult↗
PubMed1990

Radiographic distribution of Pneumocystis carinii pneumonia in patients with AIDS treated with prophylactic inhaled pentamidine.

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.

Acquired Immunodeficiency Syndrome↗