What is lung consolidation

Overview Look For Opacification obscuring pulmonary vessels Silhouette signs - obliteration of normally clear outlines between lung fields and adjacent structures Air bronchograms - tubular outlines of smaller airways No loss of lung volume.

Significance Consolidation indicates filling of the alveoli and bronchioles in the lung with pus pneumonia , fluid pulmonary oedema , blood or neoplastic cells. Lobar Consolidation Look For Consolidation of a single pulmonary lobe, without crossing any pleural lines. Causes of Lobar consolidation Lobar pneumonia Neoplasm - lung cancer, lymphoma Vascular - pulmonary haemorrhage, pulmonary infarction Cryptogenic organising pneumonia Eosinophilic pneumonia Sarcoidosis.

Example Right middle lobe consolidation in a patient with lobar pneumonia - PA film. Right middle lobe consolidation in a patient with lobar pneumonia - lateral film. Sometimes, COP shows a reversed halo sign, which is defined as central GGO surrounded by more dense airspace consolidation with crescent and ring shapes [ 5 ]. The areas of consolidation correspond histologically to the regions of lung parenchyma that show organizing pneumonia: granulation plugs lying within small airways, alveolar ducts, and alveoli [ 16 ] Fig.

The GGO correlates with areas of alveolar septal inflammation and minimal airspace fibrosis. The small nodules are related to foci of organizing pneumonia limited to the peribronchial region or to fibroblastic tissue plugs within the bronchiolar lumen.

Perilobular pattern pathologically reflects the area of organizing exudate accumulation in the perilobular alveoli, with or without interlobular septal thickening [ 15 ]. Reversed halo sign correspond to central area of alveolar septal inflammation and peripheral area of organizing pneumonia within the alveolar ducts [ 5 ]. COP responds well to corticosteroids.

Corticosteroids result in dramatic clinical improvement, with regression of symptoms within days. The overall prognosis is excellent. Spontaneous improvement over 3—6 months has been reported. Microscopically, eosinophils fill the alveoli and infiltrate the interstitium Fig.

The alveoli also contain a variable number of macrophages. The eosinophil infiltrate may involve small blood vessels but necrotizing vasculitis is not encountered: its presence would suggest Churg—Strauss allergic granulomatosis [ 17 ].

Cough and dyspnea are invariably present [ 18 ]. The severity of dyspnea is highly variable from one case to another. Wheezing occurs in about half of the case. Chest pain and hemoptysis are rare. The symptoms are most often present for at least 1 month before diagnosis is made. Weight loss, night sweating, and fever are frequent. The most common extrathoracic manifestations are cardiac, including chest pain with ST segment changes or associated pericarditis. The consolidation and GGO usually have upper lobe predominance.

Less common findings include crazy-paving pattern, nodules, and reticulation. These less common findings predominate in the later stages of CEP. CT performed more than 2 months after the onset of symptoms shows linear band-like areas of parenchymal opacity parallel to the pleural surface. Areas of consolidation on HRCT correspond histologically to accumulations of eosinophils and lymphocytes in the alveoli and interstitium and interstitial fibrosis Fig.

All the reports have confirmed the dramatic response to corticosteroids. Symptoms and pulmonary infiltrates on imaging improve within a few days of initiation of corticosteroid therapy. The findings on lung biopsy depend on the stage of the disease during which the biopsy is obtained and whether or not the patient has received therapy, particularly steroids. Lung biopsies from CSS patients in the full blown vasculitic phase may show asthmatic bronchitis, eosinophilic pneumonia, extravascular stellate granulomas, and vasculitis Fig.

Vasculitis can affect arteries, veins, or capillaries. Diffuse pulmonary hemorrhage and capillaritis can be seen [ 21 ]. Mean age of onset is 38 years. Asthma is essentially universal in CSS [ 22 ]. Virtually all patients have eosinophilia. Cardiac involvement is relatively common and is a major cause of mortality. Compared with ANCA-associated granulomatous vasculitis and microscopic polyangiitis, peripheral nerve involvement is more common while pulmonary hemorrhage and glomerulonephritis are much less common.

The most common HRCT findings consist of small centrilobular nodules, GGO, consolidation in a patchy or a predominantly subpleural distribution, bronchial wall thickening and dilatation, interlobular septal thickening, and a mosaic perfusion pattern [ 8 ] Fig. Small nodules histopathologically correlate with areas of dense eosinophilic and lymphocytic infiltration in the bronchiolar walls and patchy areas of capillaritis in alveolar walls.

The areas of consolidation correspond histopathologically to the area of eosinophilic or granulomatous inflammation predominantly in the alveoli and alveolar walls. Interlobular septal thickening may be caused by septal edema, eosinophilic infiltration, and mild fibrosis [ 8 , 23 ]. Systemic corticosteroids remain the mainstay of therapy.

Cyclophosphamide can be used in combination with corticosteroids in cases with severe disease. Older age, azotemia, and cardiac involvement are poor prognostic factors. Microscopic findings may include diffuse alveolar damage, acute interstitial pneumonia, and interstitial lymphocytic infiltration in the early phase.

There may be variable interstitial, alveolar, and replacement fibrosis in the late phase. Vascular intimal fibrosis with foamy macrophages can be seen [ 24 ]. Symptoms of radiation pneumonitis, including low-grade fever, dry cough, pleuritic chest discomfort, sensation of chest fullness, and dyspnea, usually develop 1—3 months after completion of radiation therapy [ 25 ].

In severe cases, patients may present with respiratory failure. Hemoptysis is rare. The hallmark of radiation pneumonitis on CT is the presence of increased lung attenuation corresponding closely to the location of irradiation ports Fig. Increased lung attenuations include homogeneous GGO that uniformly involves the irradiated portions, patchy consolidation that is contained within the irradiated lung, or discrete consolidation that conforms to the shape of the radiation ports [ 9 , 26 ].

Areas of GGO correspond histologically to airspace and interstitial edema and those of consolidation to diffuse alveolar damage. Corticosteroids are the mainstay of therapy. It has been shown to improve symptoms and lung function. Signs and symptoms may recur after the cessation of the therapy. Supplemental oxygen may be necessary. Late pulmonary adverse effects include pulmonary fibrosis, which is permanent and associated with marked dyspnea.

In certain diseases, the areas of consolidation are widely spread or scattered diffuse throughout the lungs. Extensive acute pneumonias including viral Fig. Viral pneumonia presenting as diffuse alveolar damage in a year-old man. Patient has no underlying illness. Also note bronchial dilatation open arrows in lower lung zones. Inset : immune staining showing many positive particles arrows in nucleus of pneumocytes. Acute interstitial pneumonia in a year-old man. Also note hyaline membranes arrows lining alveolar walls.

Acute interstitial pneumonia in proliferative phase in a year-old woman. Also note traction bronchiectasis arrows within ground-glass opacity lesions. Also note traction bronchiectasis arrows. Diffuse alveolar hemorrhage in a year-old man without specific underlying disease identified.

Specific cause of diffuse alveolar hemorrhage was not elucidated with additional histopathologic studies. A chest X-ray finding indicating the presence of a radio-opaque area in the lung. The opacification is caused by fluid or solid material within the airways or lung parenchyma. Term Hierarchy. Radiologic finding Lung consolidation. Recent clinical studies.

Etiology Lung ultrasound has greater accuracy than conventional respiratory assessment tools for the diagnosis of pleural effusion, lung consolidation and collapse: a systematic review. PMID: When the fissures are outwardly convex, the appearance is referred to as the bulging fissure sign.

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