Computed tomography of the lung in Wegener's granulomatosis

Granulomatosis with polyangiitis: Common and uncommon presentations

Granulomatosis with polyangiitis (GPA) is a multisystemic autoimmune small vessel vasculitis predominantly affecting the respiratory and renal systems. Other systems such as the central nervous system, orbital, cardiac and gastrointestinal systems may also be involved to a lesser degree. Although there are no imaging features that are pathognomonic for GPA, there are known radiological patterns suggestive of the disease and imaging plays an important role in diagnosis, assessment and monitoring of disease activity. This is more evident when combined with clinical features, biochemical values and histopathology results. This pictorial review aims to present both common and uncommon radiological features of GPA.

Pulmonary Involvement in Antineutrophil Cytoplasmic Antibodies (ANCA)-associated Vasculitis: The Influence of ANCA Subtype

OBJECTIVE

To describe pulmonary involvement at time of diagnosis in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV), as defined by computed tomography (CT).

METHODS

Patients with thoracic CT performed on or after the onset of AAV (n = 140; 75 women; granulomatosis with polyangiitis, n = 79; microscopic polyangiitis MPA, n = 61) followed at a tertiary referral center vasculitis clinic were studied. Radiological patterns of pulmonary involvement were evaluated from the CT studies using a predefined protocol, and compared to proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA specificity.

RESULTS

Of the patients, 77% had an abnormal thoracic CT study. The most common abnormality was nodular disease (24%), of which the majority were peribronchial nodules, followed by bronchiectasis and pleural effusion (19%, each), pulmonary hemorrhage and lymph node enlargement (14%, each), emphysema (13%), and cavitating lesions (11%). Central airways disease and a nodular pattern of pulmonary involvement were more common in PR3-ANCA-positive patients (p < 0.05). Usual interstitial pneumonitis (UIP) and bronchiectasis were more prevalent in MPO-ANCA-positive patients (p < 0.05). Alveolar hemorrhage, pleural effusion, lymph node enlargement, and pulmonary venous congestion were more frequent in MPO-ANCA-positive patients.

CONCLUSION

Pulmonary involvement is frequent and among 140 patients with AAV who underwent a thoracic CT study, almost 80% have pulmonary abnormalities on thoracic CT. Central airway disease occurs exclusively among patients with PR3-ANCA while UIP were mainly seen in those with MPO-ANCA. These findings may have important implications for the investigation, management, and pathogenesis of AAV.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

Pulmonary cavitary sarcoidosis: clinico-radiologic characteristics and natural history of a rare form of sarcoidosis

Pulmonary cavitary lesions in the absence of concomitant comorbidities are an uncommon and often confusing manifestation of sarcoidosis. We retrospectively reviewed the clinical and high-resolution computed tomography (HRCT) characteristics and the natural history of a series of 23 patients with pulmonary cavitary lesions found on HRCT extracted from a large cohort of patients with pulmonary sarcoidosis. The estimated prevalence of cavitary sarcoidosis was 2.2%. Cavitary lesions developed in patients with severe and active sarcoidosis (serum angiotensin-converting enzyme [SACE] > or =2 times the upper limit of normal range: 63.6%). Twelve (52.2%) patients had evidence of radiographic stage IV, 9 of whom (75%) had persistently increased SACE. As found on HRCT, cavitary lesions were multiple in 21 patients (91.3%), including 5 patients with 10 or more cavities. The size of cavitary lesions was variable, with a median diameter of 20 mm (range, 11-100 mm). Follow-up was available for 20 patients with a median follow-up of 6.25 years (range, 6 months to 15 years). Seven patients (35%) experienced some type of complication related to cavitary lesions, including 6 episodes of hemoptysis in 5 patients and aspergilloma occurrence in 3 patients. As seen on HRCT, the evolution of the number and size of cavitary lesions was variable, with a complete resolution of the largest cavitary lesion in only 5 patients (25%). During follow-up, wall thickening was always associated with a further infectious complication. In summary, cavitary lesions are rare in pulmonary sarcoidosis and usually occur in active and severe sarcoidosis. Their evolution is unpredictable, and complications are frequent.

[Pulmonary imaging in ANCA-associated vasculitides]

Imaging of ANCA-associated vasculitides principally shows nonsystematized alveolar opacities, predominantly central, that suggest alveolar hemorrhage, as well as uni- or multifocal alveolar opacities of variable interpretation, and nodules, including cavitary nodules. Other signs, observed more rarely on imaging, are interstitial lung diseases, tracheobronchial involvement, and pulmonary hypertension. The principal pulmonary signs of Wegener's granulomatosis are nodules and masses, sometimes cavitary, and areas of airspace consolidation that may or may not suggest diffuse alveolar hemorrhage. Except when the latter is present, the lesions correspond to necrotizing granulomatosis or organized pneumonia. The most frequent pulmonary signs of Churg-Strauss syndrome on computed tomography are ground glass areas or parenchymal consolidation in dispersed bands or with a predominantly subpleural distribution that expresses eosinophilic interstitial and alveolar infiltration. Alveolar hemorrhage is the most common expression of microscopic polyangiitis.

Chest CT findings in pediatric Wegener's granulomatosis

BACKGROUND

Although pulmonary involvement occurs in the majority of children and adolescents with Wegener's granulomatosis (WG), relatively little has been published regarding the CT imaging manifestations in this group of patients.

OBJECTIVE

To determine the frequency and types of chest CT abnormalities in active pediatric WG (pWG).

MATERIALS AND METHODS

The study was a retrospective examination of 29 chest CT examinations performed at diagnosis (n=14) and during disease flares (n=15) in 18 children.

RESULTS

The most common abnormalities were nodules (seen in 90% of examinations), ground-glass opacification (52%), and air-space opacification (45%). Of examinations with nodules, 73% demonstrated nodules >5 mm in diameter and 69% demonstrated more than five nodules; 17% had cavitary lesions. The only abnormality with a significant difference in prevalence between diagnosis and disease flares was air-space opacification, present in 71% and 20%, respectively (P < 0.01).

CONCLUSIONS

In accordance with the findings of published adult studies and at variance with those of prior pediatric studies, our findings indicate that chest CT abnormalities in active pWG are frequent, most commonly comprising nodules and ground-glass opacification, which may be difficult to detect on plain radiography. We therefore advocate the routine use of chest CT for all affected patients, both at the time of presentation and during disease flares.

Imaging of Wegener's granulomatosis

Wegener's granulomatosis is an uncommon multisystemic disorder of unknown aetiology. It is characterized histopathologically by necrotizing granulomatous vasculitis. Most commonly this involves the upper and lower respiratory tract, with pulmonary involvement occurring at some stage of the disease in almost all patients. However, many other organ systems can also be affected including the kidneys, orbits and central nervous system. For this pictorial review, we have assessed the imaging of 155 patients over a 10-year period in order to illustrate characteristic and some of the more unusual imaging features of Wegener's granulomatosis.

Serial high-resolution computed tomography imaging in patients with Wegener granulomatosis: differentiation between active inflammatory and chronic fibrotic lesions

PURPOSE

To evaluate pulmonary pathologies in Wegener granulomatosis with sequential computed tomography (CT) in order to differentiate active inflammatory lesions from chronic fibrotic lesions.

MATERIAL AND METHODS

Serial CT findings in 38 patients with Wegener granulomatosis were retrospectively analyzed (mean follow-up period, 21 months). The presence, extension, and distribution of the following findings were evaluated with CT: parenchymal nodules, masses, ground-glass attenuation, airspace consolidation, bronchial wall-thickening, bronchiectasis, linear areas of attenuation, pleural irregularities, pleural effusions, hilar and mediastinal lymphadenopathy.

RESULTS

Observed in 92% of patients, nodules were the most common CT pathology. Areas of ground-glass attenuation, consolidation, masses of linear attenuation, and tracheal/bronchial wall-thickening were detected in 24%, 26%, 32%, 39%, and 68% of patients. At follow-up, the clearance of lesions was most consistent for areas of ground-glass attenuation (89%), masses (87%), and cavitated nodules (85%). In the follow-up scan, 58% of all nodules, 47% of pulmonary consolidations, and 66% of bronchial wall-thickening were completely resolved. Areas of bronchiectasis and septal/non-septal lines remained stable in 70% and 71% of patients.

CONCLUSION

The majority of the lesions decreased or resolved completely with or without areas of linear attenuation. Ground-glass attenuation, cavitated nodules and masses appear to represent active inflammatory lesions. In most probability, areas of bronchiectasis and septal/non-septal lines more often represent chronic fibrotic changes rather than active inflammatory changes. In combination with clinical evaluation and bronchoscopy, CT assists in the assessment of disease activity.

Pulmonary manifestations of wegener granulomatosis: CT findings in 57 patients and a review of the literature

Wegener granulomatosis is a multisystem disease of unknown cause characterized by a necrotizing granulomatous vasculitis. In comparison to other vasculitides, the lung is the most common organ involved in wegener granulomatosis presenting with a very aggressive airways pathology and chronic relapsing course. Chest radiographs fail to describe the pattern and distribution of thoracic pathology sufficiently, and CT has shown to be more sensitive for detecting lung involvement. We present the CT findings of 57 patients with wegener granulomatosis and a review of the literature.

CT imaging of peripheral pulmonary vessel disease

The diseases concerning the small pulmonary vessels are difficult to diagnose. Pathologic findings are rarely limited to the small vessels, and a continuum between the involvement of small and large vessels is frequent. Moreover, small vessels can be affected by various disease entities with overlapping radiologic features and a wide spectrum of clinical manifestations. Nevertheless, these various entities can be easily separated into two different groups by imaging techniques, particularly by computed tomography: obstructive and inflammatory diseases. Radiologic findings of obstructive diseases are relatively constant, dominated by the manifestation of pulmonary hypertension. In contrast, radiologic manifestations of inflammatory diseases are often florid and nonspecific. After a recall of the classification of small vessel diseases and the imaging techniques, we show the computed tomography features of the principal diseases involving the small pulmonary vessels by classifying them in these two principal groups.

Unilateral phrenic nerve paralysis in a patient with Wegener's granulomatosis

A 35-year-old male diagnosed with Wegener's granulomatosis (WG) in 1989 recently came to our hospital with the complaint of left lumbar pain. He was found to have left nephrolithiasis and left diaphragmatic elevation. Fluoroscopic study and electromyographic examination revealed findings compatible with unilateral phrenic paralysis. We could not detect any cause other than WG which could be responsible for the unilateral diaphragmatic paralysis. Although different types of lung involvement have been reported in WG, to our knowledge this is the first in which unilateral phrenic nerve paralysis and diaphragmatic elevation associated with WG have been diagnosed.

Small-vessel diseases of the lung: CT-pathologic correlates

Diseases that primarily affect the small vessels of the lung are difficult to diagnose. Many conditions are characterized by involvement of small pulmonary vessels, and pathologically they can be conveniently divided into occluding and inflammatory types. The former, typified by chronic pulmonary thromboembolism and primary pulmonary hypertension, are relatively cryptic in terms of imaging. In contrast, inflammatory vasculitides, which often cause pulmonary hemorrhage and infarction, result in florid but nonspecific radiographic abnormalities. The spectrum of thin-section computed tomographic abnormalities encountered in the inflammatory vasculitides is wide: For example, in Wegener granulomatosis the pattern ranges from cavitating nodules to lobar consolidation to ground-glass opacity. This review highlights some of the less obvious imaging manifestations of occlusive and inflammatory diseases of the small pulmonary vessels.

The radiologic differential diagnosis of diffuse lung diseases characterized by multiple cysts or cavities

A variety of pulmonary diseases have diffuse cystic abnormalities within the lungs, including emphysema, cystic bronchiectasis, desquamative interstitial pneumonia, lymphocytic interstitial pneumonia, usual interstitial pneumonia, lymphangioleiomyomatosis, Langerhans histiocytosis, cystic metastasis, Wegener granulomatosis, Pneumocystis carinii pneumonia, pulmonary paragonimiasis, and septic pulmonary emboli. CT can easily detect cystic abnormalities as common features in many diseases. However, some characteristic pattern of them can facilitate specific diagnoses.

CT of noninfectious granulomatous lung disease

Noninfectious granulomatous diseases of the lung consist of a diverse group of disorders that logically can be subdivided into those with and without associated vasculitis. This article reviews the epidemiologic, clinical, pathologic, and radiologic features of sarcoidosis, hypersensitivity pneumonitis, berylliosis, and the five entities traditionally classified as pulmonary angiitis and granulomatosis.

Thoracic manifestations of systemic autoimmune diseases: radiographic and high-resolution CT findings

The systemic autoimmune diseases include collagen vascular diseases, the systemic vasculitides, Wegener granulomatosis, and Churg-Strauss syndrome. They can cause a variety of thoracic abnormalities that are influenced by the pathophysiologic characteristics of the underlying disease process. Although many of the abnormalities can be detected at chest radiography, high-resolution computed tomography (CT) has been shown to be superior in depicting parenchymal, airway, and pleural abnormalities. Thoracic manifestations of collagen vascular diseases include pleural disease, pulmonary fibrosis, diaphragm weakness, aspiration pneumonia, bronchiolitis obliterans organizing pneumonia, bronchiolitis obliterans, and bronchiectasis. Wegener granulomatosis may be associated with multiple nodules or masses with irregular margins that are frequently cavitated. Patients with Churg-Strauss syndrome often have consolidation or ground-glass attenuation at chest radiography and CT. Goodpasture syndrome is associated with extensive bilateral air-space consolidation.

Percutaneous image-guided biopsy of lung nodules in the assessment of disease activity in Wegener's granulomatosis

OBJECTIVE

In patients with known Wegener's granulomatosis (WG) and persistent chest radiographic abnormalities, assessment for disease activity is often difficult, prompting the need for histological diagnosis to determine appropriate treatment. Here we report the use of automated image-guided core needle biopsy of pulmonary lesions for the assessment of disease activity in WG, rather than for primary diagnosis.

METHODS

Image-guided percutaneous core needle biopsy was performed on five occasions in four patients with thoracic WG and persistent radiographic abnormalities of the chest. Clinical features, indication for biopsy, radiographic abnormalities and pathological findings were recorded.

RESULTS

Adequate pathological specimens were obtained, allowing exclusion of infection and tumour. Active chronic inflammation with or without vasculitis was demonstrated in each case, indicating the need for further immunosuppressive therapy. A small pneumothorax following biopsy in one case required no treatment. Follow-up chest imaging revealed a reduction in the extent of thoracic disease following therapy in all cases.

CONCLUSIONS

The safety and diagnostic accuracy of image-guided core biopsy of thoracic lesions makes it a useful tool in the assessment of disease activity in WG patients with persistent chest radiographic lesions.

Asymmetrical hemithorax volume loss due to Wegener's granulomatosis

Three patients with Wegener's granulomatosis (WG) established by clinical, serological and histological criteria were noted to have marked asymmetrical hemithorax volume loss on thoracic CT. Lung dimensions were analysed from the CT in each case. Evidence of airways disease, parenchymal abnormalities and pleural changes was evaluated on CT, in order to establish the aetiology of the volume loss. Previous pulmonary infection and thoracic intervention were excluded by the clinical data. The three patients had chronic treated thoracic WG for 1-9 years. There was severe asymmetrical pleural disease in one case and parenchymal disease with evidence of fibrotic healing but no evidence of bronchial disease in two cases. Marked asymmetrical volume loss of a hemithorax is a previously unreported finding and should be added to the features of primary chronic thoracic WG. This finding does not require investigation for additional pathology.

[Features of tomodensitometry in the development of pleuropulmonary lesions related to Wegener's granulomatosis]

PURPOSE

The aim of this study was to determine CT scan value for the follow-up of patients with pleuropulmonary lesions related to Wegener's granulomatosis.

METHODS

Retrospective study of ten patients who were diagnosed with diffuse Wegener's granulomatosis including lung involvement and for whom mean follow-up was 23 months (range 4-61).

RESULTS

During early stages of the disease, the most common finding was the existence of either nodules (90% of the patients) or consolidations (100% of the patients). CT scan controls showed that nodules disappeared within 6 months in 60% of patients and had completely resolved after 12 months. Linear opacities relating to traction developed, replacing subpleural nodules. A pneumothorax occurred in two patients who had excavated subpleural nodules. Consolidations disappeared in 44% of the patients, most frequently within 4 months. When consolidations persisted, they were replaced by alveolar infiltrates accompanied by bronchiolectasies and linear opacities. Regarding either nodules or consolidations, CT features related to relapse were similar to those of initial lesions in 40% of the cases.

CONCLUSION

The main features of pleuropulmonary lesions relating to Wegener's granulomatosis were subpleural nodules that either disappeared with, however, subsequent linear opacities sequelae, or were complicated by the occurrence of pneumothorax.

Bronchoalveolar lavage cell profiles in Wegener's granulomatosis

Pulmonary involvement due to Wegener's granulomatosis (WG) can present radiologically either as diffuse infiltrates or as nodular and linear opacities. Clinical experience suggest that these radiological patterns are associated with different bronchoalveolar lavage (BAL) cell profiles, but this has not been examined formally. We compared the BAL cell profile in eight WG patients with diffuse infiltrates on chest X-ray, indicative of highly active pneumonitis, with corresponding findings in 37 patients with nodular, linear and focal low-attenuation infiltrates on high-resolution computed tomography (HRCT) which reflected low-grade, mainly interstitial disease. A control group was composed of 11 patients with pulmonary sarcoidosis. Diffuse infiltrates occurred in association with high systemic disease activity and featured a neutrophilic BAL profile in the presence of generally normal BAL lymphocytes. HRCT findings suggestive mainly of interstitial disease were associated with either a lymphocytic BAL cell profile or a normal cell pattern. Patients with a lymphocytic cell profile generally had a preferential elevation of CD4+ cells in the BAL in the presence of a normal CD4/CD8 ratio in the blood. This was a common feature of WG and pulmonary sarcoidosis. In conclusion, highly active pneumonitis and pulmonary disease of low or moderate activity in WG are associated with disparate BAL cell profiles. It remains to be examined whether the preferential elevation of CD4+ cells in the latter condition reflects a common pathogenetic role of this subset of cells in WG and pulmonary sarcoidosis.

Radiologic manifestations of the systemic autoimmune diseases

Advances in thoracic imaging during the past two decades, such as CT scans and MR imaging, have enhanced our understanding of the pleuropulmonary abnormalities that develop in the systemic autoimmune diseases. In this article, the thoracic radiologic manifestations of several connective tissue diseases (systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, polymyositis/dermatomyositis, progressive systemic sclerosis, and anklyosing spondylitis), two granulomatous vasculitides, (Wegener's Granulomatosis and Churg-Strauss syndrome), and antiglomerular basement membrane disease are reviewed.

Tracheal involvement in Wegener's granulomatosis: evaluation using spiral CT

OBJECTIVE

To describe the computed tomography (CT) appearances of tracheal stenosis in Wegener's granulomatosis (WG) and to assess the additional value of reformatted images.

PATIENTS AND METHODS

Ten patients with tracheal involvement by WG were assessed with spiral CT and both coronal and three-dimensional surface shaded images were generated. Fibreoptic bronchoscopy was also performed in all patients.

RESULTS

Ninety per cent of lesions were situated in the subglottic region. In all cases there was circumferential mucosal thickening, in nine cases extending over a relatively short distance (mean 2.4 cm). The degree of narrowing of the axial luminal diameter ranged from 23% to 100%. In three patients there was contiguous involvement of the vocal cords evident on CT, two further cases with mild vocal cord inflammation were identified bronchoscopically. Other CT findings included mucosal irregularity and ulceration (50%), and involvement of the tracheal cartilages (20%).

CONCLUSION

Wegener's granulomatosis may involve the trachea with resultant stenosis. Spiral CT is an easily performed, non-invasive technique which provides accurate assessment of tracheal lesions and is complementary to bronchoscopy. The main additional advantage of coronal reformatted images was our added confidence in defining the upper and lower limits of lesions and in the evaluation of vocal cord involvement.

Pulmonary Wegener's granulomatosis: correlation between high-resolution CT findings and clinical scoring of disease activity

STUDY OBJECTIVE

To evaluate the usefulness of high-resolution CT (HRCT) for monitoring pulmonary disease activity in Wegener's granulomatosis (WG).

DESIGN

Prospective study of CT and clinical data.

SETTING

Main referral hospital for rheumatic diseases and department of diagnostic radiology of collaborating university hospital.

PATIENTS

Seventy-three patients with WG underwent 98 staging examinations using HRCT. The status of pulmonary disease activity at the time of examination was scored according to clinical, bronchoscopic, BAL, and radiographic findings as follows: activity (n=25, group 1), past activity (n=45, group 2) and lack of any pulmonary disease (n=28, group 3). HRCT findings were correlated with the clinical scoring of pulmonary disease activity.

RESULTS

Of 98 staging examinations 78 (79.6%) revealed abnormal CT scans showing the following main abnormalities: (a) nodules or masses (group 1: 16 [60.4%], group 2: 9 [20%]); (b) parenchymal bands (group 1: 12 [48%], group 2: 27 [60%], group 3: 6 [21.5%]); (c) septal thickening (group 1: 8 [32%], group 2: 6 [13.3%]); (d) parenchymal opacification (group 1: 7 [28%], group 2: 4 [8.9%]); and (e) pleural irregularity (group 1: 14 [56%], group 2: 22 [49%], group 3: 9 [32%]). Nodules/masses and areas of parenchymal opacification were significantly associated with florid disease activity of the lungs. Parenchymal bands and septal thickening were observed in both groups with pulmonary involvement, but statistical analysis revealed no significant difference. Pleural irregularities were nonspecific.

CONCLUSION

HRCT may be a useful adjunct to clinical scoring of pulmonary disease activity in patients with WG and suspected lung involvement.

Mediastinal mass and hilar adenopathy: rare thoracic manifestations of Wegener's granulomatosis

OBJECTIVE

To assess the frequency and characteristics of hilar and mediastinal involvement in patients with Wegener's granulomatosis (WG).

METHODS

A patient with WG presented with the unusual finding of a mediastinal mass, prompting a comprehensive review of 302 patient records from 2 WG registries to obtain evidence of hilar adenopathy or mediastinal masses. Clinic progress notes and findings of chest imaging studies (routine imaging and computed tomography) were reviewed for the presence of hilar lymphadenopathy, mediastinal masses, or mediastinal lymphadenopathy. All radiographs and surgical pathology specimens from these lesions were reviewed.

RESULTS

Six examples of mediastinal or hilar involvement (2.0%) were identified among 302 patients with WG. Three of these 6 patients had mediastinal masses. One patient with a mediastinal mass also had mediastinal lymphadenopathy. Two of the patients with mediastinal masses had lung parenchymal lesions. The remaining 3 patients had enlarged hilar lymph nodes in addition to pulmonary parenchymal lesions. All of the patients were treated with corticosteroids and cytotoxic drugs. Followup information was available on all patients. Two patients died. In the remaining 4 patients, the mediastinal mass or hilar lymphadenopathy decreased in size or resolved after 2 months of immunosuppressive therapy.

CONCLUSION

In the past, hilar adenopathy and/or mediastinal mass have been considered unlikely features of WG, and their presence has prompted consideration of an alternative diagnosis. Although this caution remains valuable, the present retrospective review of data from 2 large WG registries illustrates that such findings may rarely be a part of the spectrum of WG chest disease. Because these findings are uncommon, they necessitate consideration of a primary or concurrent infection or malignancy in the diagnostic evaluation.