Atelectasis on radiographs
The atelectasis doctors call a pathological phenomenon, when a whole lung or part of it, collapses as a result of reduction of flow of air, or the capacity of the alveoli. To diagnose this pathology is possible only when the diagnosis of radiation, so the doctor should know what it looks like atelectasis on radiographs, and what to do in case of its detection.
Pathology threat incomplete expansion of the lungs, and, consequently, a decrease in oxygenation of the blood, oxygen starvation of tissues. Also necrosis and decay of the damaged tissues, which leads to the development of intoxication.
Varieties of the disease and its place in the classification
Atelectasis is not a disease, it is only a pathological syndrome that occurs when other diseases and disorders, and are not a complication. Most often it occurs when blockage of one of the bronchi. In case of damaged main bronchi, then there is spadenie entire lung. Lobar and segmental atelectasis occurs obstruction of the bronchi of the appropriate caliber.
Sometimes it is possible to subsegmentary atelectasis, which have the form of narrow strips, placed in different parts of pulmonary fields.
In the case of destruction of the lobular bronchioles lesions appear as round seal with a diameter of two centimeters. There are also discoid or plate atelectasis, which often occur as complications after surgery. They have the form of narrow strips that cross the pulmonary field in nudepregnancy areas.
Since the pressure in the thoracic cavity falls, is pulling the diaphragm up. In the case of small volumes of diseased tissue, the severity of these symptoms decreases, and diagnose the pathology becomes more difficult. Helps a symptom of Holzknecht-Jacobson – in the inspiratory phase of respiration mediastinum as though «sticks» to the lungs, which can be seen when conducting a fluoroscopic examination or of cimagraphi.
The etiology of this disease
The causes of the disease are varied, a violation of filling the lungs with air may occur when:
- Tumors of lungs and bronchi.
- Infarction of the lung.
- Pleural empyema.
- The hydrothorax.
- The pneumothorax.
- Aspiration of foreign bodies.
- Aspiration of food masses.
Isolated primary pulmonary atelectasis – a condition of the newborn, in which after birth, the child’s lungs had not fully or partly to destroy, the alveoli are in the sleeping state and is not filled with air. Its cause is obstruction of the bronchi or amniotic fluid and mucus, or a violation of the surfactant production during fetal development.
The mechanism of development
Depending on proximate cause, which prevents the filling of the alveoli with oxygen, atelectasis may be:
- Obstructive associated with compression of the bronchi.
- The compression that occurs as the result of external pressure on the lung (a heavy object, by fluid in the pleura, tumors located outside of the lungs).
- Contracciones is the result of proliferation of inelastic fibrous tissue, which does not allow the alveoli to expand.
- Acinar arising when deficiency of surfactant in premature infants.
The techniques used in the radiographic diagnosis of atelectasis
At the first stage decided to do a panoramic radiograph of the chest cavity. It represents the total picture of the entire thickness of tissue located within the chest, the shadows of some parts in one way or another, superimposed on the shadow of the other.
To clarify the topography of the pathological process, it is necessary to take pictures in additional projections, for example, side. X-ray tomography is an excellent method for layered visualization of structures in the thorax that allows for pinpoint localization of the pathological focus and its characteristics.
Magnetic resonance imaging is used in studies of lung is relatively rare. In cases where it is necessary to differentiate pulmonary abnormalities diseases of the blood vessels and the heart, e.g., pulmonary embolism, heart failure, and is also used ultrasound, however, the lung tissue it renders bad.
The x-ray atelectasis
Telegraficheskie easy is filled with air, and on the radiograph looks like a uniform shade. There is also some additional evidence to indicate atelectasis:
- Easy reduced.
- The organs of the mediastinum shifted to the affected side.
It is believed that these criteria are sufficient to reliably diagnose «collapsed lung» during radiography, tomography and fibrobronchoscopy. However, the displacement of the bodies to the side of the lesion on the background of an extensive blackout of pulmonary fields can also be observed in fibrothorax with cirrhosis of the lung.
Differential diagnosis with other pulmonary syndromes
However, the differential diagnosis is carried out by the very nature of the shade with cirrhosis it is heterogeneous, not homogeneous. In the background you can see the sections of the whole lung tissue, swollen lobules and fibrous strands.
Infiltrative lesions usually also cause darkening in the lungs, however, despite similar kind of shade, there is no characteristic shift of the mediastinum. It is sometimes possible to distinguish between the lumens of the bronchi on the background of shadows, which allows finally to differentiate this group of pathologies from atelectasis.
Extensive dimming of high intensity can be due not only to increased density of the lung tissue, but also the accumulation of fluid in the pleural cavity, as in the case of an abundant effusion of the darkening takes on a homogeneous character and becomes quite extensive, than can recall the picture of the collapsed lung.
The key point in the differential diagnosis of these two conditions is a shift of the mediastinum. In the case of fluid in the pleural cavity is the increase of intrathoracic pressure, and the mediastinum is shifted to opposite side of lesion.
In cases where the formation of local atelectasis segmental and lobar level, you have to give a topographical description of the blackout. This allows you to set seal which share a segment or the substrate occurred. This task is easier to accomplish if the pictures were taken in two projections, as each share of each segment occupy a certain position inside the chest cavity.
Other stages of diagnostic search
The establishment of the substrate, due to which there is a blackout, this is a more difficult task. For this you need to use:
- The clinical history of the disease.
- The history of life.
- The data of the clinical examination.
- The results of laboratory tests.
- The results of instrumental methods of examination.
When to suspect the presence of atelectasis, indications for radiography
The clinical picture in the atelectasis is not specific. Persist symptoms, which preceded this complication. However, a number of symptoms should alert the physician to think about atelectasis, and serve as indications for the mandatory x-ray examination of the patient. In the case of acute development of atelectasis large amount of patients complain of chest pain, a sharp increase in shortness of breath. On examination revealed cyanosis of varying severity, affected half of the chest behind when breathing, reduced respiratory amplitude.
Over the affected lung area auscultated decreased breath sounds and dullness of percussion sound. It is possible to reduce voice jitter. May be a compensatory tachycardia, which first provides the normal level of tissue oxygenation, despite reduced oxygen capacity of the blood.
Very often develops hypotension, which can lead to collapse and shock. If the atelectasis developed on the background of infectious diseases, registers the temperature jump. However, with the gradual development of the pathology the symptoms are mild, and is diagnosed this pathology as a finding on radiographs. The shadow often has a triangular shape, its apex facing towards the root of the lung.