PubMed Health⌕ Search

Biomedical subjects

S J Swensen

Publications and source records attributed to S J Swensen.

18 recordsLinked to original sources
PubMed1992

Primary malignant ependymoma of the lung.

In a 64-year-old woman, a solitary pulmonary nodule developed 30 months after combination chemotherapy and thoracic irradiation had been administered for small-cell carcinoma of the ipsilateral lung. No evidence of extrapulmonary tumor was identified, and the nodule was excised. The well-circumscribed tumor had histologic features of a malignant ependymoma. Immunohistochemical staining showed strong reactivity for glial fibrillary acidic protein; staining for S-100 protein, Leu-7, and vimentin was less intense. Focal reactivity for epithelial membrane antigen was also present. Stains for keratin, synaptophysin, and chromogranin were negative. Electron microscopy showed cohesive cells, the cytoplasm of which contained intermediate filaments. Rare well-formed junctions were also noted. Flow cytometry of formalin-fixed paraffin-embedded tissue demonstrated DNA aneuploidy. Six months after the ependymoma was diagnosed, the patient, who had a history of hypertension, died of an intracerebral hemorrhage.

Ependymoma↗
PubMed1992

Clinical strategies for solitary pulmonary nodule.

The solitary pulmonary nodule frequently presents a diagnostic dilemma to the physician and the patient. Is it malignant or benign? Should it be observed, biopsied, or removed? Much has been learned through surgical, biopsy, and radiographic studies to help answer these questions. We review what is known about the solitary nodule and discuss the clinical approach to its evaluation.

Biopsy↗
PubMed1992

Solitary pulmonary nodule: CT evaluation of enhancement with iodinated contrast material--a preliminary report.

The authors hypothesized that the degree of contrast material enhancement of a pulmonary nodule, measured with computed tomography (CT), may indicate the likelihood of malignancy. Fifty-two patients with uncalcified solitary pulmonary nodules (diameter, 6-30 mm) were studied. Five single serial thin-section CT scans were obtained at 1-minute intervals after injection of 100 mL of nonionic contrast material. Twenty-two patients were excluded because the diagnosis was not clearly established: The observation period was less than 2 years, or the examination was technically inadequate. Malignant nodules were identified in 23 of the 30 remaining patients, and benign nodules were identified in seven. Within the first 2 minutes after the injection, all the malignant nodules had enhanced by 20 HU or greater (only one benign nodule had that degree of enhancement). The authors conclude that the degree of contrast material enhancement of pulmonary nodules as measured with CT may indicate the likelihood of malignancy.

Adult↗
PubMed1992

High-resolution CT of the lungs: findings in various pulmonary diseases.

High-resolution CT (HRCT) is a technique that optimizes the spatial resolution of conventional scanners. HRCT shows exquisite detail of both normal and diseased lung. The findings seen with HRCT of the lung correlate well with the microscopic and gross pathologic findings. In this review, we describe the technical features of HRCT and discuss the HRCT findings in various lung diseases.

Humans↗
PubMed1992

Evaluation and management of solitary and multiple pulmonary nodules.

The evaluation and management of a patient with an SPN is guided by principles that were derived from earlier surgical studies. Stability or no growth for at least 2 years, the presence of calcium in characteristic patterns, and age less than 35 years without any associated risk factors are reliable indicators of a benign process. Fluoroscopy and localized tomography are helpful in evaluation of an SPN. If the nodule is still considered indeterminate, CT scanning, with the use of thin section cuts through the nodule, is now widely employed. If calcium is present in a characteristic pattern, the nodule is considered benign. If the nodule is very dense or more dense than a phantom reference nodule, the nodule has a high likelihood of being benign. Nodules that are less dense than the phantom nodule are indeterminate, and approximately 25% of these nodules will be benign. Computed tomography scan of the chest and upper abdomen is indicated in patients with a previous history of malignancy or when there is a high suspicion that the nodule is malignant. The further evaluation and management of SPNs that are indeterminate after CT examination are controversial. Some recommend tissue biopsy via transbronchoscopic or transthoracic approach, whereas others recommend immediate thoracotomy. Observation is indicated in certain situations when the chance of malignancy is quite low, the patient is not an operable candidate, or when the patient refuses further invasive evaluation. The physician's role in the management of a patient with an SPN is to educate and advise. The physician must be aware of the patient's anxieties, fears, and attitude and provide an opportunity for active participation by the patient in the decision-making process. Multiple pulmonary nodules are most commonly encountered in patients with metastatic disease to the lungs. Other less commonly encountered diseases that present as multiple pulmonary nodules include infections, arteriovenous malformations, Wegener's granulomatosis, and lymphoma. The evaluation and management of the patient with multiple pulmonary nodules are usually guided by the history, physical examination, and laboratory findings.

Adult↗
PubMed1991

Radiology in the intensive-care unit.

Portable chest radiography is an essential component of clinical patient management in the intensive-care unit. With routine use of this procedure, unexpected cardiopulmonary abnormalities are frequently detected, and malposition or complications of intravascular devices and endotracheal, thoracostomy, or nasogastric tubes are also commonly found. The pulmonary parenchyma may be assessed for changes of acute lung injury, cardiogenic edema, areas of pneumonitis, atelectasis, or other abnormal collections of fluid or air. In mechanically ventilated patients, barotrauma occurs frequently and may be manifested by subtle intrathoracic collections of air. Technical factors may limit the resolution of the anteroposterior chest radiograph obtained at the bedside, but crucial clinical information is often gained. Portable chest radiographic findings, the role of computed tomography and ultrasonography, and interventional radiologic procedures pertinent to patients in the intensive-care unit are reviewed.

Critical Care↗
PubMed1991

Roentgenologic features of pulmonary blastomycosis.

In 35 cases of pulmonary blastomycosis, the roentgenologic features were as follows: consolidation 26%, mass 31%, intermediate-sized nodules 6%, miliary pattern 11%, solitary cavity 9%, fibrotic and cavitary changes 6%, interstitial pattern 6%, diffuse alveolar involvement 3%, and mixed alveolar and interstitial infiltrate 3%. All symptomatic cases of consolidation were acute (symptoms for less than 1 month), and most were in young patients (mean age, 34 years). Consolidation constituted 58% of the acute cases in this series. Two of the nine cases of consolidation were asymptomatic epidemic cases detected by screening. A pulmonary mass was the most common initial manifestation in this series; it tended to occur in patients with chronic symptoms (more than 1 month). The mass was considered suggestive enough of bronchogenic carcinoma to necessitate resection in 55% of cases. The military form of pulmonary blastomycosis occurred in older patients with disseminated disease. Fibrotic and cavitary disease was chronic in nature. The presence of intermediate-sized nodules elsewhere in the lung proved to be a helpful diagnostic finding in several patients with consolidation, mass, or cavitary disease. Hilar adenopathy, postinfectious calcification, chest wall invasion, and pleural effusion occurred infrequently or not at all in this series.

Adolescent↗
PubMed1991

CT evaluation of solitary pulmonary nodules: value of 185-H reference phantom.

The pulmonary nodule CT reference phantom is widely used in the evaluation of nodules 2 cm or less in diameter. It is used to detect benign patterns of calcification that are not visible on thin-section CT scans. Since 1986, the reference nodules have been manufactured with a nominal composition of 185 H. The multicenter study published in 1986 used nodules with a nominal composition of 264 H, 100 H more than the threshold value reported by Siegelman et al. in 1980. In the multicenter study, one of 37 nodules diagnosed as benign with the phantom proved to be malignant. The purpose of this study was to determine the misdiagnosis rate with the 185-H phantom and to ascertain whether the malignant tumors predicted to be benign actually contained calcification. We retrospectively reviewed 296 cases in which examinations had been performed with the 185-H nodules since 1986. Eighty-five nodules were diagnosed as benign by comparison to the reference phantom. These 85 contained no visible calcification on thin-section CT scans. Ten of the 85 cases were shown to be malignant tumors. Eight were diagnosed as having a high probability of benignity. Two were diagnosed as having a moderate probability of benignity. Calcium was present in the tissue of all six nodules available for review. Fifty-nine of the 85 nodules were still clinically indeterminate at the time of this review. Even if all of the clinically indeterminate nodules are benign, the misdiagnosis rate would be significantly higher than in most previous studies. Although analysis by using the reference phantom with 185-H nodules may indicate a high probability of benignity, close radiologic follow-up is necessary.

Adult↗
PubMed1990

An integrated approach to evaluation of the solitary pulmonary nodule.

In this article, we describe an integrated approach for detection and evaluation of solitary pulmonary nodules. Initial evaluation of the solitary pulmonary nodule includes tomography, fluoroscopy, and comparison with previously obtained roentgenograms. Subsequently, thin-section computed tomography and phantom densitometry can be used for analysis, if indicated. The rationale for the use of computed tomography in the radiologic staging of bronchogenic carcinoma is to expedite and assist in the identification of the subset of patients with resectable tumors. For nonsurgical tissue diagnosis, fiberoptic bronchoscopy is generally the initial procedure for lesions 2.0 cm or larger in diameter, and transthoracic needle biopsy is used for those smaller than 2.0 cm.

Biopsy, Needle↗
PubMed1990

Multiple cystic fibrohistiocytic tumors of the lung: report of two cases.

We describe two adults with multiple cystic fibrohistiocytic tumors of the lung that manifested as bilateral nodular opacities, cystic lesions, or both on chest roentgenograms. One patient had recurrent episodes of pneumothorax and intermittent shortness of breath; the other was asymptomatic. Open-lung biopsy specimens showed identical histologically benign fibrohistiocytic proliferations associated with formation of cysts that were lined by metaplastic bronchiolar, squamous, or type II alveolar epithelium and old hemorrhage in the cysts. In both patients, the lesions grew slowly over a period of years. These unusual multiple bilateral fibrohistiocytic tumors of the lung should be included in the differential diagnosis of bilateral cystic lesions in the lung.

Adult↗
PubMed1990

Conventional radiography of the hilum and mediastinum in bronchogenic carcinoma.

Knowledge of normal and abnormal hilar and mediastinal anatomy as depicted by chest radiography is important for the practicing radiologist. This article is an illustrated review of some of the alterations of normal anatomy that can indicate signs of metastatic spread of bronchogenic carcinoma. Thorough analysis of conventional radiographs with recognition of normal variants and detection of abnormal alterations will expedite or obviate certain therapeutic options in patients with bronchogenic carcinoma.

Carcinoma, Bronchogenic↗
PubMed1989

High-resolution computed tomography of the lung.

High-resolution computed tomography (HRCT) and thin-section CT are techniques that are particularly suited for evaluation of the pulmonary parenchyma. These techniques have been found useful in the assessment of bronchiectasis and solitary pulmonary nodules. HRCT offers promise in evaluation of diffuse and focal pulmonary parenchymal disease. The principles and applications of HRCT of the lung are reviewed.

Bronchiectasis↗
PubMed1989

Magnetic resonance imaging of the thorax.

The role of magnetic resonance imaging (MRI) in the evaluation of thoracic disease is emerging amidst much debate and study. Recent technical advances have led to new applications of this modality, and a reappraisal of previous conclusions seems warranted. This article reviews our 5 1/2 years' experience with thoracic MRI.

Contrast Media↗
PubMed1985

Use of 131I-MIBG scintigraphy in the evaluation of suspected pheochromocytoma.

Studies at the University of Michigan have shown that 131I-metaiodobenzylguanidine (131I-MIBG) is an effective agent for the diagnosis and localization of pheochromocytomas and paragangliomas. We conducted a study that confirmed and expanded that finding. From January 1983 to March 1984, 48 patients at our institution had 51 131I-MIBG scans during the workup of suspected sporadic or metastatic pheochromocytoma. Scintigrams were obtained after 500 microCI of 131I-MIBG had been administered intravenously. The final diagnosis (true-positive, false-negative, or false-positive result) was made at operation and pathologic examination. A true-negative diagnosis was confirmed by normal plasma and fractionated urinary levels of catecholamines and metabolites and, in most patients, computed tomography (CT). There were 20 true-positive studies (6 pheochromocytomas, 4 paragangliomas, and 10 metastatic or recurrent pheochromocytomas) and 24 true-negative studies. One patient with a suspected recurrent paraganglioma near the bladder had a false-positive 131I-MIBG scan (and also a false-positive (CT). Among six patients with false-negative scintigrams (three pheochromocytomas, one paraganglioma, and two metastatic lesions), one also had a false-negative CT. The overall sensitivity of 131I-MIBG scanning was 77%, specificity was 96%, and accuracy was 86%. This test is fairly sensitive in the workup of patients with known or suspected recurrent or metastatic pheochromocytoma. It may also be helpful in the evaluation of suspected sporadic pheochromocytoma when CT findings are normal.

3-Iodobenzylguanidine↗
PubMed1985

Magnetic resonance imaging of hemorrhage.

The magnetic resonance imaging (MRI) characteristics of evolving hemorrhage are discussed and compared with those of computed tomography (CT). Studies of 15 hematomas were undertaken in four mongrel dogs. The hematomas were created by the injection of autologous blood into the subcutaneous tissues of the thigh. The hematomas were studied serially with both MRI and CT. Pulse sequences included spin-echo (2100 msec TR, 40 and 80 msec TE) and inversion-recovery (2100 msec TR, 400 msec TI, 40 msec TE). Relaxation times (T1 and T2) were calculated in each case. CT values (H) were also obtained. In addition, 24 single and 14 serial scans of hemorrhage were obtained from 24 patients. MRI was performed on a 0.15-T resistive magnet scanner. T1 and T2 relaxation times and CT values decreased as the hematomas resolved. T1 and T2 relaxation times of intraparenchymal hemorrhage tended to remain elevated with time. MRI seems to be more sensitive than CT for the detection of hemorrhage, primarily because of superior contrast resolution.

Adolescent↗