Paraseptal Emphysema Research Articles

Effects of tobacco smoking on findings in chest computed tomography among asbestos-exposed workers.

This study examined the effects of smoking on the findings in chest computed tomography (CT) in 587 asbestos-exposed construction workers (11 females, 576 males, mean age 62 yrs; 18 never-smokers, 406 exsmokers and 163 current smokers). The workers were imaged with spiral CT and high-resolution CT. A total of 13 radiological signs were scored by three radiologists independently. The workers' medical data, smoking habits and occupational exposures were collected at an interview. The effects of smoking status and smoked pack-yrs (0-87.5) on the CT signs were studied using multivariate analysis adjusted for confounding factors. Smoking increased all emphysema signs and contributed to bronchial wall thickening. Smoking was negatively associated with curvilinear and septal lines as well as with parenchymal bands. In persons who had smoked <10 pack-yrs, smoking was positively related to paraseptal emphysema and to bronchial wall thickening and negatively related to septal lines, subpleural nodules and honeycombing. Smoking was related to several abnormal computed tomography signs even among those with relatively small exposure. Computed tomography can detect changes due to smoking at an early stage.

Correlation of different types of emphysema in high-resolution computed tomography (HR-CT) with the ILO-classification of coal workers pneumoconiosis

The complaints of patients suffering from pneumoconiosis and the decrease in cardio-respiratory function tests are related to the major complications, emphysema or bronchitis, resp. to a lesser degree the complaints are directly influenced by the silicotic process itself. Up to now, no large study has analysed the correlation of different types and severity of emphysema with the ILO-classification of pneumoconiosis in miners. In 104 miners the severity of pneumoconiosis was classified by ILO. By HR-CT the type and severity of emphysema was analysed using a 4-point-scale. The correlation of emphysema with the ILO-classification was tested with Pearson-correlation. The centrolobular emphysema was the dominant type with 59 %, but there was no dependence on the severity of pneumoconiosis. Only the paracicatricial emphysema had a significant correlation (p < 0.05) with the degree of large opacities. On the other hand, the paracicatricial emphysema was only detected in 32 %; under quantitative aspects it was seen to be less common than the centrolobular, the parapleural and the paraseptal emphysema (46 %). There was no significant correlation with the size and distribution of the small opacities and the different types of emphysema. Only the large opacities had a significant correlation with the appearance of paracicatricial emphysema. The other types of emphysema, especially, the dominant centrolobular type had no obvious association with pneumoconiosis. The multifactoral genesis of emphysema has to be taken into account.

Pulmonary structure and function

Computed tomography (CT) is the method of choice for the morphological assessment of pulmonary structure. Airways. pulmonary parenchyma and their pathologies are shown with high spatial resolution. Airway diseases exhibit bronchial dilatation, wall thickening and an increased visibility in the lung periphery. CT is also the imaging gold standard for the detection and the characterisation of emphysema because a high degree of concordance with histopathological studies. Centrilobular, panlobular and paraseptal emphysema can be differentiated. CT can also provide functional information. Paired inspiratory and expiratory scans with or without spirometric triggering allow to evaluate obstruction of the small airways (airtrapping). On the basis of CT-data lung volumes can be semented. Cine-CT allows to visualise motion of the central airways. e.g. in tracheomalacia, to assess regional ventilation to calculate pulmonary time constants. and to display the co-ordinated or dissociated motion of the thoracic wall and the diaphragm. Beyond the mere high-resolution visualisation of the structure of the lung the application of these CT-strategies makes a regional assessment of pulmonary function possible.

CT Assessment of Subtypes of Pulmonary Emphysema in Smokers

ObjectiveTo determine the incidence of subtypes of pulmonary emphysema (PE) identified by CT imaging in male patients who have a significant smoking history. Patients and settingWe reviewed 945 subjects (619 men and 326 women) who had undergone CT scanning. However, only the data for male subjects were analyzed due to there being too few female subjects. The male subjects were divided into the following two age groups: group A (age, ≤ 50 years) and group B (> 50 years). There were two subtypes of PE found: centrilobular emphysema (CLE) and paraseptal emphysema (PSE). Based on these subtypes, PE was divided into the following three categories: I (CLE or CLE-predominant); II (CLE and PSE of equal extent); and III (PSE or PSE-predominant). ResultsPE was found in 270 of 516 male smokers (10 of 38 female smokers had PE). Among male subjects, in age group A there were 53 subjects with some degree of PE (category I, 12 subjects [22.6%]; category II, 7 subjects[13.2%]; and category III, 34 subjects [64.2%]). Among men in age group B, there were 217 subjects with some degree of PE (category I, 109 subjects [50.2%]; category II, 23 subjects [10.6%]; and category III, 85 subjects [39.2%]). ConclusionIn age group A, men < 50 years of age who were in category III (PSE or PSE-predominant PE) predominated (34 of 53 subjects; 64.2%). In age group B, men > 50 years of age who were in category I (CLE or CLE-predominant PE) predominated (109 of 217 subjects; 50.2%).

Plain radiographs and thoracic high-resolution CT in patients with ankylosing spondylitis.

The aims of this study were to identify the spectrum of abnormalities seen on high-resolution CT in patients with ankylosing spondylitis and to compare our findings with reports of plain film pulmonary manifestations of the disease. We prospectively studied 26 patients with documented ankylosing spondylitis. All patients underwent plain chest radiography (posteroanterior and lateral views), thoracic helical CT, high-resolution CT, and pulmonary function tests. High-resolution CT revealed abnormalities in 18 patients (69%), whereas plain chest radiography revealed abnormalities in four patients (15%). The most common abnormalities seen on CT were interstitial lung disease (ILD) (n = 4), bronchial wall thickening and bronchiectasis (n = 6), paraseptal emphysema (n = 3), mediastinal lymphadenopathy (n = 3), tracheal dilatation (n = 2), and apical fibrosis (n = 2). This study, which describes high-resolution CT findings in patients with ankylosing spondylitis, reveals a spectrum of abnormalities unlike those described in previous reports in which researchers used plain chest radiographs as the sole imaging technique. In addition to apical fibrosis, high-resolution CT revealed nonapical ILD, bronchiectasis, paraseptal emphysema, and tracheobronchomegaly. Of these new findings, we believe that identification of ILD is the most important. We suggest that nonapical ILD should be actively sought as an explanation for pulmonary symptoms developing in patients with ankylosing spondylitis. High-resolution CT should form an integral part of such workup.

Idiopathic giant bullous emphysema (vanishing lung syndrome): imaging findings in nine patients.

We reviewed the imaging findings in nine patients with idiopathic giant bullous emphysema. This progressive condition is characterized by large bullae, usually seen in association with several forms of emphysema, and usually occurs in young men, most of whom are smokers. Nine patients with chest radiographic evidence of a bulla or bullae occupying at least one third of a hemithorax, who had also been examined with high-resolution CT, were included in this retrospective study. We examined the size, distribution, and locations of bullae. On high-resolution CT scans, bullae were categorized as predominantly subpleural or intraparenchymal. In eight of the nine cases, the chest radiographs showed variable asymmetry in the distribution of bullae. Bullous disease involved predominantly the upper lobes. High-resolution CT showed bullae from 1 to 20 cm in diameter, but most were 2-8 cm in diameter. Paraseptal emphysema and subpleural bullae were the predominant findings in all nine patients. Seven patients had separate centrilobular emphysema of various degrees and intraparenchymal bullae. None of the intraparenchymal bullae were larger than 2-3 cm. Additionally, two non-small-cell lung cancers were seen in our series. The dominant and consistent feature seen on high-resolution CT scans in both smokers and nonsmokers is extensive paraseptal emphysema merging into giant bullae. Associated centrilobular emphysema, seen in cigarette smokers, is the important variable finding for determining the extent of underlying parenchymal disease, which may help in the preoperative assessment of giant bullous lung disease.

HYPERSENSITIVITY PNEUMONITIS

Emphysema is most commonly associated with smoking but also occurs in hypersensitivity pneumonitis (HP). The aim of this study was to further explore this relationship.A retrospective, computer-assisted search was performed to identify patients with HP seen at Mayo Clinic in Rochester, Minnesota, from January 1997 through February 2014. Demographic, clinical, and imaging features were analyzed. Patients were excluded if they had a smoking history of 10 pack-years or more.Twelve patients (9 males) with HP and computed tomographic evidence of emphysema were identified. Ten were never smokers and 2 were ex-smokers. The median age at diagnosis was 47 (range, 29–77) years; median symptom duration was 2.2 (range, 0.2–13.4) years. The most common presenting symptoms were dyspnea (83%) and cough (67%). On pulmonary function testing, 6 patients (50%) had a restrictive defect, 2 (17%) had airflow obstruction, and 4 (33%) had an isolated reduction in diffusing capacity of lung for carbon monoxide. The severity of emphysema ranged from mild to severe to focal bullae. All patients had chronic hypersensitivity pneumonitis (CHP). Centrilobular emphysema was most commonly seen with coexistent paraseptal emphysema in 5 patients.Emphysema was most frequent in the upper lung but could be seen in any lobe.Emphysema can occur in patients with CHP independently of smoking history and exposure to specific types of antigens. Emphysematous changes seem to progress at a slower pace compare to reticulations/fibrosis.

Sequential Morphologic Changes of Elastase-Induced Pulmonary Emphysema in Pig Lungs

The authors evaluated the early morphologic changes of elastase-induced pulmonary emphysema in the pig and correlated the findings with high-resolution computed tomography (HRCT). Nine Yorkshire pigs were included in this investigation; in seven, pulmonary emphysema was induced by 2 mg/kg body weight of elastase instilled selectively into the left lower lobe bronchus. Animals were studied by CT at 0, 1, 2, 3, 7, 14, and 21 days. At the completion of the experiment, the lungs were removed, inflated, fixed and dried, and subsequently sliced corresponding to the CT sections. The gross appearance, histologic appearance, and HRCT were correlated. On HRCT, sequential changes from early edema to development of emphysema were noted. Panlobular, centrilobular and paraseptal emphysema were observed. Elastase-induced pulmonary emphysema in the pig is a useful and reproducible animal model, and high-resolution computed tomography depicts the morphologic changes observed both by gross pathologic observations and histologic observations.

Patient work-up for bullectomy.

A localized area of hypertransradiance often leads to surgical referral. Among 608 cases, 115 were due to local lesions of airways, blood vessels, or parenchyma. Among the remaining 493 with bullae from diffuse emphysema, 21% underwent surgery. Good restoration of function occurred in patients with rapidly progressive dyspnea who did not have a bronchitic component, recurrent infections, or CO2 retention. Physiologically, preoperative findings suggestive of tension pneumothorax, including severe restriction, marked air trapping, and little ventilation/perfusion mismatch suggested good results. Favorable radiographic findings included well-defined, large air spaces without stigmata of diffuse emphysema, serial films showing rapid enlargement of bullae, and expiration films with good thoracic motion and obscuration of lung around bullae. Compressed but otherwise intact lung was best demonstrated by angiography and CT scans. Palliative bullectomy in severe diffuse emphysema sometimes had gratifying clinical results. Resection of small bullae never caused improvement. Localized giant bullae most often were associated with paraseptal or periacinar emphysema, and the best surgical results were obtained in this group.

CT in the qualitative assessment of emphysema.

To assess the ability of CT to demonstrate the different types of emphysema, the CT appearance was compared with the corresponding barium-impregnated pathologic specimens cut in the transverse plane, in four patients with emphysema. The CT appearance was also compared with the chest radiographs of two patients with irregular emphysema associated with progressive massive fibrosis. The parenchymal destruction visualized on CT in the patients with mild and moderate centriacinar emphysema was distinctly different from that seen in the patient with panacinar emphysema in appearance and distribution. Paraseptal and irregular emphysema were also well demonstrated using CT. Window widths between 800 and 1,500 were found to demonstrate the parenchymal changes most accurately. We conclude that CT can help to identify the presence of emphysema and to distinguish radiologic characteristics of the different types of emphysema.

Immunological function in mice chronically exposed to nitrogen oxides (NO x)

BALB c mice were exposed to 10 ppm NO or NO 2 for 2 hr daily on weekdays, for varying periods up to 30 weeks. At intervals of approximately 7 weeks, groups of animals were subjected to a variety of pathological and immunological examinations: serum antibody responses to both T-dependent and T-independent antigens, spleen cell PHA and graft-versus-host responses, capacity to reject a transplanted tumor, routine hematology, and lung pathology. Tests of immune function indicated suppression resulting from chronic exposure to these gases, and in most cases data indicated enhancement of immunological reactivity by shorter exposures. NO 2 appeared somewhat more potent than NO in this regard, but the differences observed were not great. Chronic NO exposure produced a more severe lung pathology, with clear evidence of paraseptal emphysema.

Long-term results of surgery for bullous emphysema

We present long-term clinical, radiologic, and physiological data in 84 patients (mean age 46.5 -11.7 years) who underwent 95 surgical procedures for bullous emphysema from 1949 to 1972. Surgical indications were dyspnea (57), pneumothorax (18), prophylaxis (13), infection (6), and hemoptysis (1). Physiological improvement was related to bulla size, type of surgery and degree of chronic obstructive lung disease. Best results, often sustained for 5 years, generally occurred in patients with giant bullae, those with lesser degrees of chronic obstructive lung disease, and those who underwent simple bulla excision or plication. Worthwhile short-term improvement occurred in some patients with cor pulmonale. Poorest results were obtained in patients whose bullae were mere localized exaggerations of diffuse emphysema; in severe bronchitis; in cases in which bullae occupied one third or less of one hemithorax; and after lobectomy. Paraseptal (periacinar) emphysema, a benign disease of the lung cortex, was associated with a high prevalence of pneumothorax. Function was maintained for up to 20 years following bullectomy, and there was little tendency for the bullae to recur.

Peri-acinar (paraseptal) emphysema: Its clinical, radiological, and physiological features

Two patients with paraseptal (peri-acinar) emphysema are described. Bilateral spontaneous pneumothorax occurred in one patient and rapid enlargement of a bulla in the other, in each case causing severe acute dyspnœa: neither had complained of dyspnœa before. The radiographic features were the combination of hair-line ring and polygonal shadows with avascular areas distributed under the pleura, characteristic of the condition. Pulmonary function studies showed remarkably little airway obstruction and the lungs were evenly ventilated: the minor degree of impairment was consistent with a cushioning effect of the peripheral bull˦. One of the patients died after operation, enabling detailed pathological studies of this unusual condition to be made.