Metastatic non-small cell lung carcinoma with involvement of extremity musculature: case report and review of the literature.

Hematogenous dissemination of non-small cell lung carcinoma (NSCLC) metastatic to skeletal musculature in the absence of osseous involvement is an infrequent occurrence. We retrospectively reviewed our institution's indexed database for patients evaluated from 1975 through 1997 who were diagnosed as having skeletal musculature metastases from NSCLC. Eight men and 2 women were identified (age range, 51-80 years at time of metastases). Four primary adenocarcinomas, 4 primary lung squamous cell carcinomas (SCCs), and 2 poorly differentiated primary NSCLCs were identified. Approximate tumor sizes ranged from 10 cm3 to 288 cm3. External-beam radiation therapy was used in 7 of 10 cases; complete surgical excision was performed in 3 cases. Patients with known neoplasm who have extremity pain and negative findings on bone scan should be evaluated for soft tissue tumor involvement because such findings significantly affect clinical management. One case of lung SCC metastatic to the quadratus femoris muscle in a 63-year-old man is discussed in detail.

Advanced multiple beam equalization radiography: receiver operating characteristic comparison with screen-film chest radiography.

OBJECTIVE: To test the hypothesis that the advanced multiple beam equalization radiography (AMBER) imaging system is superior to conventional chest radiography in the demonstration of diffuse infiltrative lung disease, emphysema, pulmonary nodules, calcification within nodules, and mediastinal or hilar masses and lymphadenopathy. MATERIAL AND METHODS: The study involved 115 patients, each of whom underwent chest computed tomography (CT), AMBER, posteroanterior chest radiography, and conventional posteroanterior stereoscopic chest radiography (two films). All radiographs were obtained with the InSight Thoracic Imaging System. Four chest radiologists independently analyzed the 115 AMBER studies, 115 unpaired single conventional radiographs (a single film from a stereoscopic pair), and 115 stereoscopic conventional radiographs (2 films) for the presence of diffuse infiltrative lung disease, emphysema, pulmonary nodules, calcification within nodules, and mediastinal or hilar masses and lymphadenopathy. For each abnormality detected, the radiologists described their level of confidence based on a scale of 1 to 5. The 115 CT examinations were interpreted by consensus among 3 of the chest radiologists. The CT results were considered the standard. Receiver operating characteristic (ROC) techniques were used for statistical analysis. RESULTS: No statistically significant differences were found with ROC techniques between the AMBER system and single or stereoscopic conventional screen-film radiography for the abnormalities studied. CONCLUSION: We noted no clinically significant difference between AMBER and either single or stereoscopic conventional screen-film radiography in this prospective study of 115 patients in which CT (performed within 1 week of both radiographic examinations) was the standard.

Detection of subtle abnormalities on chest radiographs after irreversible compression.

PURPOSE: To assess the effect of wavelet-based compression of posteroanterior chest radiographs on detection of small uncalcified pulmonary nodules and fibrosis. MATERIALS AND METHODS: Computed tomography (CT) of the chest was used to identify 20 patients with normal posteroanterior chest radiographs, 20 with a solitary uncalcified pulmonary nodule 1-2 cm in diameter, and 20 with fibrotic disease. A double-blind protocol for readings of original images and images compressed at 40:1 and 80:1 was analyzed by using the nonparametric receiver operating characteristic to measure differences in diagnostic accuracy and their statistical significance. RESULTS: There was no substantial difference in the overall diagnostic accuracy (measured by the area under the curve index) for both nodules and fibrosis between images compressed at 40:1 and 80:1 and uncompressed images. Readers tended to perform better on images compressed at 40:1 compared with uncompressed images. The "high-sensitivity" portion of the 80:1 compression curve for nodules was below that for the uncompressed curve, although this was not statistically significant. CONCLUSION: Lossy compression of chest radiographs at 40:1 can be used without decreased diagnostic accuracy for detection of pulmonary nodules and fibrosis. There is no statistically significant difference in diagnostic accuracy at 80:1 compression, but detection ability is decreased.

Evaluation of irreversible compression of digitized posterior-anterior chest radiographs.

The purpose of this article is to assess lossy image compression of digitized chest radiographs using radiologist assessment of anatomic structures and numerical measurements of image accuracy. Forty posterior-anterior (PA) chest radiographs were digitized and compressed using an irreversible wavelet technique at 10, 20, 40, and 80:1. These were presented in a blinded fashion with an uncompressed image for A-B comparison of 11 anatomic structures as well as overall quality assessments. Mean error, root-mean square (RMS) error, maximum pixel error, and number of pixels within 1% of original value were also computed for compression ratios from ratios from 5:1 to 80:1. We found that at low compression (10:1) there was a slight preference for compressed images. There was no significant difference at 20:1 and 40:1. There was a slight preference on some structures for the original compared with 80:1 compressed images. Numerical measures showed high image faithfulness, both in terms of number of pixels that were within 1% of their original value, and by the average error for all pixels. Our findings suggest that lossy compression at 40:1 or more can be used without perceptible loss in the representation of anatomic structures. On this finding, we will do a receiver-operator characteristic (ROC) analysis of nodule detection in lossy compressed images using 40:1 compression.

The radiographic findings of fibrosing mediastinitis.

We retrospectively reviewed the radiographic findings of fibrosing mediastinitis (FM) in 33 patients. Imaging studies included chest radiographs, computed tomographic scans, magnetic resonance imaging examinations, esophograms, ventilation perfusion scans, angiograms, and venograms. Findings include bronchial narrowing in 11 patients (33 percent), pulmonary artery obstruction/narrowing in 6 patients (18 percent), esophageal narrowing in 3 patients (9 percent), and superior vena cava obstruction/narrowing in 13 patients (39 percent). Two distinctly different radiographic patterns were identified: a localized pattern seen in 27 patients (82 percent) that frequently contained calcification and a diffuse pattern seen in 6 patients (18 percent) that did not contain calcification. The localized pattern is most likely due to histoplasmosis and does not show radiographic evidence of improvement with steroid therapy. The diffuse pattern may more likely be truly idiopathic or of a noninfectious etiology. Several patients with the diffuse pattern showed radiographic evidence of improvement with steroid therapy.

A new asymmetric screen-film combination for conventional chest radiography: evaluation in 50 patients.

OBJECTIVE: A new asymmetric screen-film combination for conventional chest radiography was evaluated by four thoracic radiologists. MATERIALS AND METHODS: Fifty chest radiographs obtained with a new asymmetric screen-film combination were compared with radiographs obtained in the same patients during the same breath-hold with a conventional system. Patients referred from the oncology service were studied because of the increased prevalence of abnormal findings on chest radiographs in this population. The differences in the quality of the images were assessed by four chest radiologists who used a direct-comparison technique. Eleven anatomic shadows that are normal on chest radiographs were assessed. Fifty abnormal findings also were compared. RESULTS: The image quality of the new asymmetric screen-film combination was judged to be superior to that of the conventional system for normal anatomy and abnormal findings (p < or = .003). CONCLUSION: The new asymmetric film consistently showed more clinically useful detail in the mediastinum and in the lung projected over the diaphragm and heart. The radiation dose was about 30% less with the new screen-film system.

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.