Nonspecific interstitial pneumonia associated with polymyositis and dermatomyositis: serial high-resolution CT findings and functional correlation.

STUDY OBJECTIVES: We described the features seen on serial high-resolution CT scans of nonspecific interstitial pneumonia (NSIP) that was associated with polymyositis (PM) and dermatomyositis (DM), and we correlated the changes in the CT scan findings with those of pulmonary function test results. DESIGN, SETTING AND PATIENTS: Serial CT scans of 14 patients with histologically proven NSIP and PM/DM from two university hospitals were evaluated retrospectively (follow-up period, 3 to 61 months; mean follow-up period, 27.6 months). Using initial and follow-up CT scan findings, the extent of each type of opacity and the total area of increased opacity were calculated and correlated with the results of pulmonary function tests. MEASUREMENTS AND RESULTS: The predominant findings on the initial CT scans were of reticular and/or ground-glass opacities with or without consolidation. Reticular and ground-glass opacities predominated in the lower zone of each lung, and consolidation predominated at the lung periphery. Thirteen patients showed significant improvement of the total area of increased opacity (p < 0.05), and this decrease in extent inversely correlated with changes in FVC (r = -0.650; p = 0.031). Ground-glass and reticular opacities also were improved significantly in 11 and 13 patients, respectively. The decrease in the extent of ground-glass opacity correlated inversely with the changes in FVC (r = -0.758; p = 0.0119) and diffusion capacity for carbon monoxide (r = -0.669; p = 0.0448). In one patient, ground-glass opacity progressed, and death occurred after 3 months. Traction bronchiectasis was seen in 12 patients, and it improved in four patients after treatment. Honeycomb lung was not noted in any patient during follow-up. CONCLUSIONS: With treatment, serial CT scans of PM/DM patients with NSIP showed significant improvement in the abnormal opacities, and radiographic progression of lung fibrosis was limited. The CT scan features and clinical course of NSIP in PM/DM patients were relatively uniform, and this constitutes a subset of NSIP.

Epidural air associated with spontaneous pneumomediastinum in children: uncommon complication?

BACKGROUND: The purpose of the present study was to evaluate the incidence of epidural air associated with spontaneous pneumomediastinum in children. METHODS: The subjects consisted of 25 boys and 17 girls with an age range of 3-14 years (mean age: 8.5 years) who underwent chest computed tomography (CT) for evaluation of spontaneous pneumomediastinum. The CT scans and medical records were reviewed retrospectively. RESULTS: Of the 42 patients, four (9.5%) had intraspinal air on CT. The air was interpreted as epidural in every patient. The small number of patients with epidural air meant that there was no significant difference in age, gender, or clinical manifestations between groups with and without epidural air. Subcutaneous emphysema was identified in all four patients with epidural air versus 18 out of 38 patients (47%) without epidural air. The patients with epidural air did not have any neurologic symptoms. Irrespective of the presence or absence of epidural air, every patient had a favorable outcome without any serious complications. CONCLUSION: In patients with spontaneous pneumomediastinum, epidural air may be more common than was previously realized. It is suggested that an air leak may spread from the mediastinum into the epidural space via the cervical fascial planes and neural foramina.

Pleural disease in silicosis: pleural thickening, effusion, and invagination.

PURPOSE: To retrospectively evaluate pleural disease on images from patients with autopsy-proved silicosis. MATERIALS AND METHODS: The study had institutional review board approval, and informed consent from relatives of diseased subjects was waived. Lung specimens were obtained at autopsy in 110 men (mean age, 72 years) who had been followed up radiologically for a mean of 14.8 years. Computed tomographic (CT) scans obtained within 2 years before death were examined for presence of pleural thickening; shape, composition, size, and subpleural location of progressive massive fibrosis (PMF); and pleural invagination (bandlike structure between lesion and pleura). Lung specimens were reviewed and compared with CT findings. Serial chest radiographs and CT scans were reviewed for presence of pleural effusion. Association between radiographic findings and pleural invagination was analyzed with chi2 and Student t tests. Multiple logistic regression analysis was used to find predictive variables for pleural invagination. RESULTS: Pleural effusion was found in 12 (11%) patients at chest radiography and CT, and thickening was found in 64 (58%) patients at CT; the latter finding was significantly more frequent with complicated silicosis (P < .001). At CT, 128 PMF lesions were seen, 39 (30%) of which showed pleural invagination; CT scans showed pleural thickening in 36 (92%) of these 39 lesions. In 17 (44%) PMF lesions, CT scans depicted a bandlike structure that was pathologically confirmed to represent invaginated pleura in all cases. Pathologic presence of invagination was significantly associated with pleural thickening (P < .001), ipsilateral pleural effusion (P < .01), interstitial fibrosis (P < .05), and the nearness of PMF to the pleura (P < .005). Multiple logistic regression analysis showed that pleural thickening (odds ratio, 62.51; 95% confidence interval [CI]: 5.564, 70.2) and pleural effusion (odds ratio, 25.865; 95% CI: 1.992, 335.8) were significant CT variables associated with presence of pathologic pleural invagination (P = .001 and .013, respectively). Five PMF lesions had radiographic features of rounded atelectasis. CONCLUSION: Various pleural abnormalities can occur in silicosis, especially in advanced disease.

Silicosis: expiratory thin-section CT assessment of airway obstruction.

PURPOSE: To prospectively evaluate if findings on paired inspiratory and expiratory thin-section computed tomographic (CT) scans in patients with silicosis correlate with pulmonary function test results. MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. Thirty-seven men (mean age, 71 years; range, 53-88 years) with silicosis were included. All patients had undergone inspiratory and expiratory thin-section CT and spirometry. Silicotic nodules, large opacity, emphysema, reticular opacities, bronchiectasis, and air trapping were graded subjectively on CT images. Emphysema was quantified on these images with built-in software. CT numbers were correlated with spirometric findings by using Spearman rank correlation analyses. Ten healthy volunteers (three men and seven women; mean age, 58 years) served as control subjects. RESULTS: After exclusion of three patients with inadequate image quality, 34 patients (mean age, 70 years; range, 53-88 years) were enrolled in the study group. Spirometric values did not differ significantly between patients with simple (n = 20) and patients with complicated (n = 14) silicosis but were significantly lower in patients than in control subjects. CT findings included air trapping (n = 33), emphysema (n = 26), nodules (n = 32), bronchiectasis (n = 22), large opacity (n = 19), and reticulation (n = 5). The extent of both air trapping and emphysema correlated negatively with spirometric values; the air trapping score showed the strongest correlation (ratio of forced expiratory volume in 1 second to forced vital capacity [FVC]: rho = -0.632, P < .001; forced expiratory flow at 50% of the FVC: rho = -0.576, P = .001). Silicotic nodule, large opacity, and bronchiectasis scores did not correlate with obstructive functional impairments. CONCLUSION: In comparison with the spirometric value, the extent of air trapping proved the best CT index in the assessment of obstructive derangement in workers with exposure to silica dust.

Chronic pulmonary thromboembolism. Air trapping on computed tomography and correlation with pulmonary function tests.

OBJECTIVE: We evaluated lung attenuation on inspiratory/expiratory computed tomography (CT) and spiral CT angiography (CTA) from patients with chronic pulmonary embolism and correlated the CT findings with pulmonary function test (PFT) results. METHODS: We retrospectively reviewed 9 patients with chronic embolism (mean age, 62.3 years; 5 women and 4 men). Paired inspiratory, expiratory CT and matching CTA images were reviewed, and lung attenuation was evaluated in each segment. Lower attenuation on inspiratory images and air trapping on expiratory images were subjectively assessed and correlated with PFT results. The relationship between the presence of clot and lung attenuation was evaluated. Nine age-matched normal subjects served as controls. RESULTS: Lower attenuation with mosaic perfusion and air trapping were identified in 6 and 9 patients, respectively (mean scores, 8.1 and 11.3, respectively). Air trapping was identified in 19 (42.2%) of 45 segments with lower attenuation on inspiratory images, but was also noted in 31 segments with normal inspiratory attenuation. Air trapping was associated with the presence of proximal arterial stenosis (P<0.01), and the area showed less contrast enhancement than the adjacent lung (P<0.05). Extent of air trapping correlated inversely with PFT parameters of peripheral airway obstruction such as maximum mid-expiratory flow rate (r=-0.86, P=0.003). On the other hand, extent of mosaic perfusion did not correlate with PFT. CONCLUSIONS: Air trapping is commonly seen in chronic embolism and is found in areas of relative hypoperfusion. The extent of air trapping correlates with parameters of peripheral airway obstruction.