Performing high-resolution computed tomography in asbestos-exposed patients.
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Asbestosis↗
Biomedical subjects
T C McLoud
Publications and source records attributed to T C McLoud.
Surgical flaps in the chest: anatomic considerations, applications, and radiologic appearance.
PURPOSE: To determine the frequency of use of surgical flaps--tissue that is transposed from its normal location to promote healing and prevent complications--in noncardiac thoracic surgery and to demonstrate the typical radiologic appearances of such flaps. MATERIALS AND METHODS: The surgical records of 200 patients who underwent thoracotomy or median sternotomy for noncardiac thoracic surgery were reviewed. Postoperative radiologic studies of randomly selected cases were also reviewed. RESULTS: A total of 213 surgical flaps were used in these patients, including 80 pericardial fat pad flaps (37.6%), 78 greater omental flaps (36.6%), 21 intercostal muscle flaps (9.9%), 16 anterior serratus muscle flaps (7.5%), and 18 greater pectoral muscle, latissimus dorsi muscle, pleural, thymic, or mediastinal fat flaps (8.5%). The flaps produced unusual opacity or attenuation and/or contour of the mediastinum, hilum, or chest wall. CONCLUSION: Knowledge of common thoracic surgical flaps is helpful in interpretation of postoperative radiologic studies.
Adipose Tissue↗
Needle localization of peripheral lung nodules for video-assisted thoracoscopic surgery.
Video-assisted thoracoscopic surgery provides an alternative to conventional thoracotomy for resection of peripheral lung nodules. To localize small peripheral lung nodules that may not be visible or palpable by the surgeon, we have placed a Kopans hook wire percutaneously into the lung as a guide. The indications for localization included previous nondiagnostic percutaneous needle aspiration biopsy (PNAB) (n = 4), nodules too small for PNAB (n = 2), nodules inaccessible to PNAB (n = 3), and planned resection of a known peripheral tumor less than 1 cm (n = 1). The localization procedure was performed with computed tomographic guidance in all patients. The nodules ranged in size from 2 to 15 mm and were located immediately subpleural to 2-cm deep the pleura. A 20-gauge Greene biopsy needle was used as an introducer for a 35-cm-long Kopans hook wire. Patients were sent directly to the operating room in a dependent position. All ten nodules were successfully resected, including hamartoma (n = 1), carcinoid tumors (n = 2), granulomas (n = 3), adenocarcinoma (n = 1), fibrosis (n = 1), benign metastasizing leiomyoma (n = 1), and lymphoma (n = 1). In two patients, the wire slipped out of the lung. Small focal pneumothoraces developed in five patients. There were no major complications. This procedure can safely and effectively localize nonvisible or nonpalpable pulmonary nodules for thoracoscopic surgery for diagnostic purposes or for resection of small peripheral tumors in patients who cannot tolerate a lobectomy or pneumonectomy.
Aged↗
Adenosquamous carcinoma of the lung: radiologic appearance.
OBJECTIVE: To our knowledge, the imaging features of pulmonary adenosquamous carcinoma, a form of bronchogenic carcinoma with a greater propensity for metastases at the time of diagnosis and a poorer prognosis than other forms of bronchogenic carcinoma, have not been reported. Accordingly, we studied the radiologic appearance of this tumor to describe the findings and discern if there are features that distinguish it from other bronchogenic carcinomas. MATERIALS AND METHODS: Clinical and radiologic features of 30 cases of adenosquamous carcinoma were reviewed. Chest radiographs were available in all cases and CT scans were available in 23. In cases without CT scans, planar tomograms were reviewed in five cases and MR images were reviewed in one. Tumors were defined by location, morphology, and TNM classification. RESULTS: The tumors measured 0.6-6.5 cm in diameter (mean, 2.8 cm) on CT scans or chest radiographs. One tumor not seen even in retrospect on CT scans or chest radiographs was found at autopsy. Twenty-five tumors were solid and four were cavitary. Five tumors were central and 25 were peripheral, including one tumor of the superior sulcus of the lung and the tumor not seen at imaging. Tumor margins were poorly defined in 19 and spiculated in 10. Four large masses had heterogeneous attenuation on CT scans; one had punctate calcification. Fifty-three percent of tumors were peripheral nodules 1-3 cm in diameter. Results of fine-needle aspiration of 18 masses indicated malignant tumors in 16 cases, but adenosquamous carcinoma in only two. Evidence of previous lung injury, including tumor in or next to scar, pneumoconiosis, radiation fibrosis, and interstitial fibrosis, was found on CT scans, chest radiographs, and/or pathology in half the patients. CONCLUSION: The radiologic findings of adenosquamous lung carcinoma are a spectrum, typically a peripheral solitary nodule, less commonly a central hilar mass or tumor of the superior sulcus. Scar or fibrosis within the lungs suggests that adenosquamous carcinoma, just as adenocarcinoma, may arise in scarred lung parenchyma.
Aged↗
Imaging of mediastinal foregut cysts.
This study was undertaken to determine the value of magnetic resonance imaging (MRI) in the diagnosis of mediastinal foregut cysts. The MRI scans of 56 patients (with a total of 57 mediastinal masses) were reviewed. The patients (26 women and 30 men) had been examined between March 1986 and April 1991 at a tertiary-care hospital. T1-weighted and T2-weighted spin-echo images were available in all cases. The signal intensity of the lesions was compared with that of normal fat and muscle; the size, shape and location of the mediastinal masses were also noted. The 57 lesions consisted of 15 lymphomas, 10 neurogenic tumours, 10 thyroid masses, 6 thymomas, 6 foregut cysts and 10 other masses. Forty-eight of the masses had a signal intensity similar to that of muscle in T1-weighted images and higher than, equal to or lower than that of fat in T2-weighted images. Nine of the masses appeared bright in T1-weighted images, and the signal intensity was less than or equal to that of fat. Of these, four were foregut cysts and five were lymphomas. Of the six foregut cysts, four had short T1 values (the signal intensity ratio for cyst to fat ranging from 0.78 to 0.98) and long T2 values; two had the characteristic appearance usually associated with cystic lesions containing serous fluid--long T1 and T2 values. All of the foregut cysts appeared to be of soft-tissue attenuation on computed tomography (CT), all were located in the middle or posterior mediastinum, and all were round or oval.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Chest CT in patients with scleroderma: prevalence of asymptomatic esophageal dilatation and mediastinal lymphadenopathy.
OBJECTIVE: The high-resolution CT findings of chronic diffuse interstitial lung disease associated with scleroderma have been reported previously. This study determined the prevalence of esophageal dilatation and mediastinal adenopathy on high-resolution CT scans in patients with this disease. MATERIALS AND METHODS: We retrospectively reviewed the high-resolution CT scans of 25 patients with scleroderma who had diffuse interstitial lung disease. Esophageal dilatation was diagnosed if the esophagus below the aortic arch had a single, large, nonloculated collection of intraluminal air on four or more consecutive axial images and if the luminal diameter of such an air-filled esophagus exceeded 10 mm in the coronal plane. The presence of fluid or an air-fluid level was also considered abnormal. For mediastinal adenopathy, we used the American Thoracic Society lymph node mapping scheme and the size criteria described previously. RESULTS: Asymptomatic esophageal dilatation was detected in 20 patients (80%) and mediastinal adenopathy was present in 15 (60%). CONCLUSION: Our results suggest that CT is useful in the detection of mediastinal adenopathy and asymptomatic esophageal involvement in patients with scleroderma. These findings can be used to narrow the differential diagnosis in patients in whom CT shows diffuse interstitial lung disease. Furthermore, the early detection of esophageal involvement in these patients shows the need for treatment to forestall the complications of esophageal dysmotility and accompanying chronic gastroesophageal reflux.
Adult↗
Idiopathic laryngotracheal stenosis: radiologic findings.
OBJECTIVE: Acquired nonneoplastic laryngotracheal stenosis can be either focal or diffuse. Diffuse tracheal stenosis is caused by sarcoidosis, tuberculosis, histoplasmosis, relapsing polychondritis, tracheopathia osteoplastica, and Wegener's granulomatosis. Focal tracheal stenosis, on the other hand, usually results from placement of an endotracheal or tracheostomy tube or from previous neck trauma. At our institution, since 1971, we have seen 49 cases of focal laryngotracheal stenosis that could not be attributed clinically or histologically to any one of the aforementioned causes. The purpose of this study was to study the radiologic features of these idiopathic laryngotracheal stenoses. MATERIALS AND METHODS: A retrospective review of records showed that radiologic studies were still available in only 15 of the 49 patients with idiopathic laryngotracheal stenoses. All 15 patients had radiographs and plain tomograms, and one patient had a CT scan of the neck. Three radiologists reviewed all the images. RESULTS: The radiologic appearance was variable: the stenoses were from 2 to 4 cm long with a lumen between 3 and 5 mm in diameter at the narrowest portion. The narrowing was concentric and shaped like an hourglass in eight patients (53%) and was eccentric in the other seven (47%). The margins of the stenosis were smooth in nine patients (60%) and irregular and lobulated in six patients (40%). A dominant mass measuring approximately 1 cm in diameter was present in two patients (13%). No evidence of calcification or ossification was seen. CONCLUSION: Idiopathic laryngotracheal stenosis produces focal stenosis of the cervical part of the trachea, 2 to 4 cm long. The lumen is severely compromised, measuring no more than 5 mm in diameter at its narrowest portion. The stenosis can be concentric or eccentric and can have either smooth or lobulated margins. Special attention should be paid to the airways when chest radiographs of patients with a history of prolonged dyspnea and wheezing are reviewed. The prevalence of focal stenosis of the larynx and the upper part of the trachea due to tracheal intubation has declined since the introduction of low-pressure, high-volume retention cuffs. Therefore, idiopathic laryngotracheal stenosis should be considered in the differential diagnosis in patients with focal narrowing of the airway.
Adolescent↗
Lung tumor metastasis to breast detected by fluorine-18-fluorodeoxyglucose PET.
We report a case of breast metastasis from a large-cell bronchogenic adenocarcinoma. Serial 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) was used to monitor the response of the primary lesion to radiation therapy. In the 7-wk interval between studies, an area of markedly increased FDG uptake appeared in the right breast. On subsequent biopsy this proved to be a metastatic deposit from the primary lesion. breast metastasis is uncommon. The ability of FDG-PET to detect metastatic lesions from primary lung tumor is variable. In this case, the finding of the new breast lesion resulted in introduction of chemotherapy to the treatment program.
Breast Neoplasms↗
T-cell alveolitis in lung lavage of asbestos-exposed subjects.
In sarcoidosis and idiopathic pulmonary fibrosis, it has been reported that lymphocyte proportions in lung lavage predict the subsequent clinical course. Recent evidence has suggested that lymphocytes are important in the alveolitis of asbestosis. We hypothesized that a greater relative proportion of T-lymphocytes in lung lavage of asbestos-exposed subjects is associated with immune activation and may predict the subsequent clinical course. We assessed lymphocyte subsets in lung lavage and peripheral blood (PB) of 97 asbestos-exposed subjects and 10 unexposed normal, using flow cytometry analysis of monoclonal antibody-treated cells. T-cell alveolitis was defined as follows: [%lymphocytes in lavage x %CD3 in lavage] greater than 2 SD above that product in normals. Eighteen subjects had T-cell alveolitis (group 1) and 79 did not (group 2). There were no significant differences between the groups in age, smoking status, duration of exposure, lung function results, or frequency of plaques or profusion greater than or equal to 1/0. Percent CD2 was higher in lavage of group 1 compared with group 2. There was a trend for higher %Ia in lavage of group 1 compared with group 2. These results identify a subgroup of asbestos-exposed subjects with T-cell alveolitis but no present excess of asbestos-related disease who may be at risk for future asbestos-related disease.
Adult↗
Bronchogenic carcinoma: analysis of staging in the mediastinum with CT by correlative lymph node mapping and sampling.
One hundred forty-three patients with bronchogenic carcinoma were studied prospectively with computed tomography (CT) to determine the accuracy of CT in the evaluation of mediastinal nodal metastases. Mediastinal lymph nodes were localized according to the lymph node mapping scheme of the American Thoracic Society and were considered abnormal if they exceeded 1 cm in short-axis diameter. All patients underwent surgical staging, which consisted of either mediastinoscopy alone or mediastinoscopy and thoracotomy. At the time of surgical staging, all accessible nodes were either removed or sampled. The sensitivity of CT for mediastinal nodes on a per-patient basis was 64%, with a specificity of 62%. The sensitivity of CT for individual nodal stations involved with tumor was only 44%. The presence of obstructive pneumonitis did not appreciably alter the sensitivity of CT, but the specificity was lower (43%). The likelihood of metastases increased with lymph node size; however, seven of 19 (37%) lymph nodes that measured 2-4 cm in short-axis diameter were hyperplastic and did not contain metastases. The relative insensitivity of CT makes formal nodal sampling at the time of mediastinoscopy or thoracotomy essential to detect lymph node metastases.
Adult↗
Catheter-induced pulmonary artery pseudoaneurysm: the halo sign on CT.
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Aged↗
Conventional radiography in the diagnosis of asbestos-related disease.
Standard chest radiography, despite its limitations, remains an important means of evaluating the asbestos-exposed worker. Because of its wide availability, low radiation dose, and low cost, it will continue to be the standard imaging procedure for the screening of asbestos-exposed populations.
Asbestos↗
Thoracic disease in the immunocompromised patient.
Thoracic disease in the HIV negative immunocompromised host is most frequently caused by infection. Patterns of involvement produced on the chest radiograph include (1) lobar or segmental consolidation, (2) nodules with rapid growth and/or cavitation, and (3) diffuse lung disease. The lung also may be directly involved by lymphoma, metastases, drug reactions, radiation pneumonitis, or nonspecific interstitial pneumonitis. The lung is a frequent target organ for opportunistic infections in AIDS patients, particularly of Pneumocystis carinii pneumonia and tuberculosis. Computed tomography may be particularly helpful in these patients in the detection of early disease and in the characterization of patterns and extent of involvement as well as complications.
Acquired Immunodeficiency Syndrome↗
Differentiation of bronchogenic carcinoma from postobstructive pneumonitis by magnetic resonance imaging: histopathologic correlation.
Obstructive pneumonitis frequently occurs distal to hilar bronchogenic carcinomas or in lung adjacent to peripheral tumors. The article evaluates the role of MRI in the differentiation of tumor from pneumonitis. Twelve patients underwent MRI of the thorax before surgery. T1-weighted (SE 310/20) and T2-weighted (SE 2000/60-120) images were obtained through the tumor and presumed areas of pneumonitis. Five histologic types of pneumonitis were identified on pathologic examination of the 12 specimens. Cholesterol pneumonitis, found in 7 patients, was the most common type. Organizing pneumonitis, bronchiectasis with mucus plugs, atelectasis, and abscess were found in 3, 4, 2, and 1 patients, respectively. MRI was able to differentiate tumor from pneumonitis in 5 of 6 patients with a hilar mass and in 5 of 6 patients with a peripheral tumor. This was achieved by a visual difference in signal intensity on heavily T2-weighted (SE 2000/120) images. Cholesterol pneumonitis and bronchiectasis with mucus plugs were always hyperintense relative to tumor, and organizing pneumonitis and atelectasis were isointense and indistinguishable from tumor. MRI can differentiate tumor from pneumonitis provided that pneumonitis is of the cholesterol type or if there are mucus plugs in the collapsed lung.
Aged↗
Effect of patient positioning after needle aspiration lung biopsy.
Fifty-five patients who underwent fluoroscopically guided needle aspiration lung biopsy were randomly assigned to one of two postbiopsy treatment groups: Patients were placed recumbent with puncture site either down (n = 36) or up (n = 19) for at least 1 hour. No significant difference in pneumothorax rate was seen between the two groups. Chest tube placement, however, was required in 21% (four of 19) of the puncture-site-up group versus 3% (one of 36) of the puncture-site-down group, which was a significant difference (P = .04). Puncture-site-down postbiopsy positioning reduces the proportion of patients requiring chest tube placement after lung biopsy.
Biopsy, Needle↗
Asbestos exposure and asbestos-related pleural and parenchymal disease. Associations with immune imbalance.
The study hypothesis was that asbestos exposure and asbestos-related pleural plaques and interstitial disease are associated with (1) immune imbalances favoring helper-inducer T-cell subsets in blood and bronchoalveolar lavage (BAL) and (2) T-lymphocyte accumulation in BAL. One hundred twenty-two asbestos-exposed subsets (AES), including 27 nonsmokers (NS), were evaluated and compared with 10 unexposed normal subjects. Data were collected on medical, smoking, and occupational histories, physical examination, spirometry, lung volumes, single-breath DLCO, chest films read by a "B" reader, and T-lymphocyte characterization in blood and BAL using flow cytometry analysis of monoclonal-antibody-treated cells. On average, AES were 47 yr of age and had 23 yr of asbestos exposure. Fifty-eight (48%) had pleural thickening, and seven (6%) had profusion greater than or equal to 1/0. In blood, asbestos-exposed NS had lower total and percent CD8 and lower total CD3 than did normal subjects. In BAL, asbestos-exposed NS had higher total CD3 than did normal subjects. Among AES, increased asbestos exposure was associated with increased percent CD8 in BAL and decreases in both percent lymphocytes and total CD8 in blood. Increase in CD4/CD8 ratio in BAL were associated with pleural thickening. In those seven with profusion greater than or equal to 1/0, there was increased percent CD4 in blood and decreased percent CD8 in BAL. These results suggest immune imbalance favoring helper-inducer T-cell subsets in association with asbestos exposure systemically and with pleural plaques in BAL.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Imaging the pleura: sonography, CT, and MR imaging.
A variety of imaging techniques can be used to evaluate the pleura and the pleural space. Standard radiographs are the most common. In this article, however, we review the use of three other imaging techniques: sonography, CT, and MR imaging. Sonography allows easy identification of pleural fluid and loculation and differentiation from pleural masses; CT is best for characterizing location and composition of pleural masses; MR is somewhat limited, but is best for imaging superior sulcus carcinoma.
Diagnostic Imaging↗
Occupational lung disease.
The pneumoconioses, extrinsic allergic alveolitis, lung damage due to irritant gases, fumes, and smoke constitute the occupational lung diseases that affect the lung parenchyma. The pneumoconioses are diseases resulting from the accumulation of dust in the lungs. The ILO has established a standardized system for classification of these pneumoconioses that includes both descriptions of diffuse lung opacities and pleural disease. The most common of the fibrogenic pneumoconioses are silicosis, CWP, and asbestosis. The former two entities are characterized radiographically by the presence of small rounded opacities or nodules in the lung parenchyma. Eggshell calcification may occur in lymph nodes, and eventually the diseases may be complicated by the development of large massive areas of fibrosis in the upper lung zones. Asbestosis, on the other hand, demonstrates small irregular or linear opacities usually confined to the bases of the lungs. It is associated with significant respiratory symptoms and disability. High resolution CT has proved useful in characterizing the parenchymal changes and also in identifying early disease in all of these entities. Berylliosis is a systemic disorder that in its chronic form produces granulomatous disease in the lungs. Radiographically it is characterized by the development of either small rounded or occasionally irregular linear opacities usually confined to the bases. Chemical pneumonitis results from exposure to toxic fumes. The acute reaction may produce diffuse lung injury characterized by air-space disease typical of pulmonary edema. In the chronic form, bronchiolitis obliterans supervenes. This usually is associated with either a normal radiograph or evidence of hyperinflation. Finally, hypersensitivity pneumonitis or extrinsic allergic alveolitis is a response of the lung to inhalation of antigens that may be present in the workplace. Either acute, subacute, or chronic disease may result. In the chronic form, a diffuse reticulonodular pattern with or without associated lymphadenopathy is characteristic.
Alveolitis, Extrinsic Allergic↗