X-ray for lung cancer: what does the radiograph?
By the end of 2015 in Russia were 3404237 people with cancer (2,32% of the population). Of them 133863 sick of ZNO (malignant neoplasms) respiratory (3.9% of the total number of patients dispensaries). Although lung cancer is the frequency of occurrence of inferior tumors at other sites (tumors of the breast, uterus, colon, haematopoietic system), the disease has not become less dangerous.
X-ray diagnostics – the most common method of detecting lung cancer, including early stages. But only x-ray studies, even informative (CT) is insufficient for diagnosis. Lung cancer (and other bodies) needs to be confirmed by results of histological examination. Therefore, the x-ray is mandatory, but not the only diagnostic procedure recommended for suspected lung EIT. However, in this article, we will discuss only radiographic.
- Radiography – getting the picture of the chest in various projections: main – line and side in a standing position, additional rear lying on your back, naturography lying on its side, front and rear oblique. The lungs are clearly visible without injection of contrast. The latter is used for visualization of some structures: blood vessels, bronchi, pleural cavity, mediastinum.
- Linear tomography – obtaining cross-sectional images of the chest cavity on the longitudinal sections. The study is performed on a conventional x-ray apparatus. Unlike x-ray method allows to consider in more detail the pathological education and the bodies in the plane of the slice.
- Computed tomography is a highly informative method of diagnosis of lung diseases. It is based on obtaining cross-sectional images of organs in cross section. Contrast enhancement when performing CT is used to study vessels of the pulmonary circulation and to assess the status of the lymph nodes and the extent of TESTING.
- Radionuclide – radiation of the radiotracer. Radionuclides are injected intravenously or inhaled in the composition of the breathing mixture. This study allows to estimate the respiratory function of the blood flow in the pulmonary circulation.
Thus, the x-ray is not the only method of research in lung cancer. Often it is complemented by other diagnostic techniques, primarily CT. Among the methods not related to irradiation, most important is endoscopy: bronchoscopy, thoracoscopy, mediastinoscopy. The role of ultrasound and MRI in the diagnosis of lung diseases is limited. Ultrasound is used for examination of the pleural cavity, structures of the chest wall, heart and great vessels. MRI is effective in the examination of the roots of the lungs, pleura, chest wall.
Lung cancer – pathology requiring the use of several diagnostic methods, including x-rays is used at the initial stage, but to confirm the diagnosis alone is not sufficient.
Roentgenography of organs of a thorax in the diagnosis of malignant tumors
Radiograph allows to judge the condition of the bone structures, lung, pleura. The organs of the mediastinum (heart, esophagus) details to consider in conventional radiography can not. In the picture they look like the middle shade, which can only indirectly be judged on their condition. Radiography is a simple and informative method of diagnosis of pathological conditions of the respiratory system, has almost no contraindications, is well tolerated by patients. Radiation exposure is 0.03 and 0.3 mSv in the study on digital and film apparatus respectively.
X-ray of the lungs is assigned with detection of pathological changes on fluorogram; the presence of symptoms indicating diseases of the respiratory system (pneumonia, tuberculosis, abscess, pleural effusion, tumor); injuries to the chest; the suspicion of a foreign body. For lung cancer, radiography is among the obligatory studies. This procedure allows one to specify the localization and prevalence of process. For more detailed information, the study is generally completed by data of CT.
Radiography for suspected cancer runs in straight line and lateral projections in a standing position. To obtain high-quality picture with the chest and neck should be removed all the items: clothes, jewelry. Long hair should be collected in a bun at the nape. Any special preparations the study is not required.
X-ray is contraindicated for pregnant women. However, in this case an exception. The research method is preferably in the third trimester. If you can not wait, the is done at an early time and in compliance with measures that protect the fetus from radiation.
Decoding of the result
How does the EIT of the lungs on x-ray:
- Central cancer develops from the epithelium of the large bronchi. It can grow in the lumen of the respiratory tract in the direction of the lung tissue or be placed around the bronchus, squeezing it from outside. X-rays showed the tumor looks like a shadow with irregular contour located in the region of the root of the lung. If a tumor spreads to the surrounding tissues in the picture appear rough bands, like rays. The disease is accompanied by compression from the outside or closure of the lumen of a major bronchus with endobronchial nature of growth of the tumor. As a result, the airiness of the lung decreases, and when complete bronchial obstruction this segment collapses (atelectasis occurs). The picture shows such a plot looks like a shadow of a triangle with the apex facing the root of the lung. Swing to the neighboring areas due to compensatory hyperventilation increases. The mediastinum is often displaced in the direction of the pathological process. There may be a rise of the diaphragm on the affected side.
- Peripheral cancer arises from the epithelium of bronchial tubes. In the picture it is visible as a shadow with a radiant contours. A characteristic feature is the «track» of the tumor to the root of the lung is manifestation of cancerous lymphangitis, inflammation of the lymphatic vessels. With the spread of large bronchi, their germination and squeezing occur atelectasis and areas of high lightness as the Central form of ZNO. Lymph nodes the root of the lung is increased.
- Disintegrating peripheral cancer. Shadow of the tumor is a cavity, sometimes with a fluid level. In contrast to the abscess wall such education is uneven, with radiant tyazhistosti, you may find a «track» going to the root of the lung.
- Cancer Pancoast – variant TESTING peripheral localization in the apex of the lung. It is often said the destruction of the rear sections I-III of the ribs and transverse processes of the vertebrae, the lower cervical and/or upper thoracic.
- When miliary carcinomatosis in lung shadow detected multiple small and medium sizes.
- When the mediastinal cancer affects the organs of the mediastinum. The main changes on the x-ray will increase and deformation of the median shadow. Often there is an increase of lymph nodes of root of the lung.
The signs of malignancy detected on the radiograph shadows are uneven contour, the presence of fibrous bands, the «path» to the root of the lung.
Additional methods of diagnostics
To clarify the diagnosis when x-ray signs of ZNO easy apply:
- imaging (computer linear is preferable, as it gives a clearer picture);
- bronchoscopy with taking of material for histological examination;
- needle biopsy.
CT sensitivity and specificity is superior to x-rays allows us to see difficult to see on plain x-ray structures of the mediastinum. However, radiation exposure with this method of diagnosis is higher, the average is 11 mSv for 1 procedure. During pregnancy, CT scan is absolutely contraindicated.
Histological research is necessary to confirm the diagnosis. Therefore, bronchoscopy with biopsy is always performed in cases of suspected Central cancer. Reliable signs of ZNO in this study are concentric narrowing of the bronchus with the rigidity of the walls, towering above the surface of the mucosa or infiltrates growths with a rough surface. To obtain material from the peripheral of the tumor by transthoracic puncture.