X-ray symptoms of lung lesions

Lung and diaphragm damage

In acute closed or open chest and lung trauma, all victims require radiological examination. The urgency of its implementation and scope are decided on the basis of clinical data. The main task is to exclude damage to internal organs, assess the condition of the ribs, sternum and spine, as well as detect possible foreign bodies and establish their localization. The importance of radiological methods increases due to the difficulty of clinical examination of patients due to shock, acute respiratory failure, subcutaneous emphysema, hemorrhage, severe pain, etc.

In case of necessity to perform urgent resuscitation measures or surgical intervention, the radiological examination, consisting of general radiography of the lungs with increased voltage on the tube, is performed directly in the intensive care unit or operating room. In the absence of such urgent indications and in a less severe condition of the victim, he is taken to the X-ray room, where radiographs of the lungs and, if possible, CT are performed. In addition, it is advisable to perform sonography of the abdominal organs, in particular the kidneys. Pathological changes in the organs of the chest cavity can gradually increase, and from the 3rd to the 5th day, sometimes such a complication as pneumonia joins them, therefore, radiographs of the lungs in case of damage to internal organs must be repeated within several days.

Rib fractures accompanied by displacement of fragments are easily detected on images. In the absence of displacement, fracture recognition is aided by the detection of a parapleural hematoma, as well as a thin fracture line on targeted radiographs taken in accordance with the pain point. Fractures of the sternum, clavicles and vertebrae are quite clearly defined. Compression fractures of the vertebral bodies with varying degrees of wedge-shaped deformation are usually observed.

With both open and closed chest trauma, the integrity of the lung may be compromised (ruptured).

A pathognomonic sign of a lung rupture is the accumulation of gas in the pleural cavity - pneumothorax or directly in the lung parenchyma in the form of a cavity - a "traumatic cyst".

With simultaneous damage to the pleura, gas from the pleural cavity enters the soft tissues of the chest wall. Against the background of these tissues and pulmonary fields, a peculiar "feathery" pattern appears on the images - the result of the stratification of muscle fibers by gas. In addition, gas can penetrate into the mediastinal tissue through the interstitial space of the lung, which is manifested on radiographs as mediastinal emphysema.

Directly in the lung tissue, areas of compaction may be distinguished, varying in intensity, shape and extent. They represent a zone of parenchyma impregnation with blood, foci of edema, subsegmental and lobular atelectasis. Sometimes hemorrhages in the lung tissue appear as multiple small foci or, conversely, a single round hematoma.

Violation of the integrity of the pleural cavity is accompanied by hemorrhage. In most cases, blood accumulates in the pleural cavity, causing a picture of hemothorax. When the victim is in a horizontal position, hemothorax causes a general decrease in the transparency of the pulmonary field, and when in a vertical position, it causes darkening in its outer and lower sections with an oblique upper border. Simultaneous entry of air (in case of open trauma) or gas from the lung (in case of lung rupture) into the pleural cavity causes a typical picture of hemopneumothorax, in which the upper level of fluid remains horizontal in any position of the body.

Injury to the diaphragm is accompanied by a high position of its damaged half and limitation of motor function. In case of prolapse of abdominal organs through a defect in the diaphragm, the radiologist discovers an unusual formation in the chest cavity, delimited from the lung tissue and adjacent to the thoracoabdominal septum (traumatic diaphragmatic hernia). If intestinal loops have penetrated into the chest cavity, this formation consists of gas accumulations separated by narrow partitions. Such a hernia is characterized by variability of the radiographic shadow, and when the patient's body position changes and repeated examinations make it possible to establish which parts of the digestive tract have prolapsed into the chest cavity and where the hernial orifices are located: at the level of the latter, a narrowing of the intestinal lumen is noted.

Unfortunately, chest trauma is often complicated by the development of pneumonia, abscess, and pleural empyema. Radiation methods - radiography, tomography, and computed tomography - provide their recognition. If a bronchopleural fistula is suspected, bronchography is used. Scintigraphy is useful for assessing the state of capillary blood flow in the lung and the functional capacity of the lung tissue.

Acute pneumonia

Acute pneumonia is manifested by inflammatory infiltration of the lung tissue. In the infiltrate zone, the alveoli are filled with exudate, due to which the airiness of the lung tissue decreases and it absorbs X-rays more strongly than normal. In this regard, X-ray examination is the leading method for recognizing pneumonia. It allows you to determine the prevalence of the process, reactive changes in the roots of the lungs, pleura, diaphragm, promptly detect complications and monitor the effectiveness of treatment.

Chest radiography is especially important in cases of atypical clinical pneumonia caused by mycoplasma, chlamydia, legionella, pneumonia in patients with immunodeficiency and hospital-acquired pneumonia that occurs after surgery and artificial ventilation.

All acute pneumonias can be recognized with the help of a properly performed X-ray examination. The inflammatory infiltrate is defined as a darkened area against the background of air-filled lungs. In this area, air-containing bronchi are often visible as narrow light stripes. The boundaries of the infiltrated zone are blurred, with the exception of the side that adjoins the interlobar pleura.

The radiographic picture of lobar pneumonia is determined by which lobe of the lung is affected. Continuous infiltration of the entire lobe is rare. Usually the process is limited to part of the lobe or one or two segments. Knowing the location of the segments, it is possible to accurately determine the affected area. In lobular pneumonia, radiographs show round or irregular darkenings 1-2.5 cm in size with unclear outlines, located against the background of an enhanced pulmonary pattern in groups in one lung or both lungs. They can merge into large foci of confluent pneumonia. There are also cases of small-focal pneumonia, when mainly the acini are affected. The size of the foci in this case varies from 0.1 to 0.3 cm. In acute pneumonia, infiltration of the root tissue on the affected side and a small amount of fluid in the costophrenic sinus are often recorded. The mobility of the corresponding half of the diaphragm decreases. During the patient's recovery, the shadow of the infiltrated area gradually weakens or disintegrates into separate small areas, between which the pulmonary lobules that have regained their airiness are located. Radiographic changes are usually observed longer than clinical signs of recovery, so a conclusion about complete recovery can be made based on the results of a joint assessment of clinical and radiographic data. One of the unfavorable complications of pneumonia is purulent melting of the lung tissue with the formation of an abscess. In these cases, a cavity containing gas and liquid is determined in the infiltrate.

Pulmonary artery branch thromboembolism

Pulmonary artery branch thromboembolism occurs as a result of an embolus carried in from the veins of the lower extremities and pelvis (especially common in thrombophlebitis or phlebothrombosis of the iliac-femoral segment of the venous system), thrombosed inferior or superior vena cava, or heart (in thromboendocarditis). Clinical diagnostics are far from always reliable. The classic triad of symptoms - dyspnea, hemoptysis, flank pain - is observed in only 1/4 of patients, so radiological examination is of exceptional value.

The tactics of radiological examination depend on the location of the thrombus and the patient's condition. In case of a threatening clinical picture with a sharp overload of the right ventricle of the heart, urgent radiography or computed tomography of the chest organs is indicated. Signs of blockage of a large artery are an enlargement of the right chambers of the heart, increased contractions of the right ventricle, expansion of the superior vena cava, weakening of the pulmonary pattern in the branching zone of the thrombosed vessel. It is possible to expand this vessel proximally to the affected section, and sometimes even "amputate" the vessel at this level. If it is possible to perform angiography on a spiral computed tomography scanner or magnetic resonance angiography of the lungs, then the size and location of the thrombus are accurately determined. The same data can be obtained with urgent angiopulmonography. In this case, catheterization of the pulmonary artery is performed not only for contrasting the vessels, but also for performing subsequent anticoagulation and other endovascular interventions.

In a less severe condition of the patient, chest X-ray is also performed first. The X-ray symptoms of pulmonary embolism are taken into account: dilation of the pulmonary artery trunk, increased amplitude of contractions of the right ventricle of the heart, weakening of the vascular pattern in the affected area, elevation of the diaphragm on the same side, lamellar atelectasis in the area of reduced perfusion, a small amount of fluid in the costophrenic sinus.

Later, a hemorrhagic infarction may develop in the affected area. Its volume depends on the caliber of the thrombosed artery and ranges from a small 2-3 cm lesion to an entire segment. The base of the compacted area is usually located subpleurally, and it casts a triangular or oval shadow on the film. If the course is unfavorable, complications are possible: tissue breakdown in the infarction area, development of an abscess and pneumonia, pleurisy.

Perfusion scintigraphy plays an important role in recognizing thromboembolism of large branches of the pulmonary artery. Accordingly, a defect in the accumulation of radiopharmaceuticals is detected in the area of reduced or absent blood flow. The larger this defect, the larger the branch of the artery is affected. In the case of embolization of small branches, heterogeneity of the lung image and the presence of small areas of damage are noted.

Of course, the results of scintigraphy should be assessed taking into account clinical and radiographic data, since similar accumulation defects can be observed in other pulmonary diseases accompanied by a decrease in pulmonary blood flow: pneumonia, tumor, emphysema. In order to increase the accuracy of interpretation of perfusion scintigrams, ventilation scintigraphy is performed. It allows identifying local ventilation disorders in obstructive pulmonary diseases: obstructive bronchitis, emphysema, bronchial asthma, lung cancer. However, it is in thromboembolism that ventilation scintigrams do not show defects, since the bronchi in the affected area are passable.

Thus, a characteristic sign of pulmonary embolism is a defect in the accumulation of radiopharmaceuticals on perfusion scintigrams with a normal picture on ventilation scintigrams. Such a combination is practically not registered in other lung diseases.

Chronic bronchitis and pulmonary emphysema

Chronic bronchitis is a group of common diseases in which there is a diffuse inflammatory lesion of the bronchial tree. A distinction is made between simple (uncomplicated) and complicated bronchitis. The latter manifests itself in three forms: obstructive, mucopurulent and mixed bronchitis.

In the diagnosis of simple bronchitis, radiation methods are of little importance, and the main role is played by fibrobronchoscopy. The task of the radiologist is primarily to exclude other lung lesions that can cause similar clinical signs (pulmonary tuberculosis, cancer, etc.). X-rays only show an increase in the pulmonary pattern, mainly in the lower sections, due to thickening of the bronchial walls and peribronchial sclerosis. A completely different matter is the recognition of obstructive forms of bronchitis, in which the results of X-ray and radionuclide studies serve as an important addition to the clinical data. X-rays, tomograms and computer tomograms with obstructive bronchitis show three groups of symptoms:

1. increase in the volume of connective tissue in the lungs;
2. emphysema and pulmonary hypertension;
3. relatively small size of the heart.

The increase in the volume of connective tissue is expressed primarily in thickening of the bronchial walls and peribronchial sclerosis. As a result, the images show, especially in the root zones, bronchial lumens bordered by a narrow shadow strip (the "tram rails" symptom). If these bronchi are reflected in the axial section, they stand out as small ring-shaped shadows with an external uneven contour. Due to the development of fibrous tissue, the pulmonary pattern takes on a reticular appearance. As a rule, fibrous deformation of the roots of the lungs is also detected. Narrowing of the lumen of small bronchi leads to the development of diffuse pulmonary emphysema and pulmonary hypertension. The radiographic picture of these conditions was described above. The displacement of the ribs and diaphragm during breathing decreases, as do the differences in the transparency of the lung fields during inhalation and exhalation; the area of the lung fields is increased.

The radiographic picture of obstructive bronchitis is so characteristic that there is usually no need for special contrasting of the bronchi - bronchography. Bronchographic symptoms of bronchitis are varied. The most important of them are considered to be the penetration of the contrast agent into the dilated mouths of the bronchial glands (adenoectasis), deformation of the bronchi with uneven contours, spasms of the bronchi in the area of their mouth or along their length, non-filling of small branches, the presence of small cavities (cavernicules), accumulation of sputum in the lumen of the bronchi, causing various defects in the accumulation of the radiopharmaceutical in the shadow of the bronchi.

In lung scintigraphy, in addition to an increase in lung fields and a general decrease in the accumulation of the radiopharmaceutical, defects in its distribution are often noted. They correspond to areas of impaired blood flow and ventilation - emphysematous bubbles and bullae. Emphysematous cavities are very clearly outlined on computer tomograms.

Chronic pneumonia and limited non-specific pneumosclerosis

X-ray examination allows to recognize all forms and stages of chronic pneumonia. The images show infiltration of lung tissue. It causes non-uniform darkening due to a combination of infiltration and sclerosis areas, coarse fibrous strands, bronchial lumens bordered by a strip of peribronchial sclerosis. The process can capture part of a segment, part of a lobe, an entire lobe or even the entire lung. In the shadow of the infiltrate, individual cavities containing liquid and gas can be seen. The picture is complemented by fibrous deformation of the root of the lung and pleural layers around the affected part of the lung.

However, the doctor is always in danger of mistaking limited non-specific pneumosclerosis for chronic pneumonia, which occurs as a result of previous pneumonia, which ended not in complete resorption of infiltration, but in the development of a fibrous (scar) field. Radiographs also show non-uniform darkening caused by a combination of areas of sclerosis and lobular emphysema. The altered section of the lung is reduced in size, intertwined strands of fibrous tissue are visible in it, between which there are rosette-like light areas - swollen lobes, but unlike pneumonia, there are no foci of infiltration and especially small purulent cavities, the outlines of all shadow elements are sharp, not blurry. On repeated images, the picture does not change. There are no clinical and laboratory signs of a chronic inflammatory process, except for signs of regional bronchitis, which sometimes worsens in areas of pneumosclerosis.

In order to get an idea of the condition of the bronchial tree in chronic pneumonia and bronchiectasis, computed tomography is performed, and only if it is impossible to perform, bronchography is used. Bronchograms make it possible to distinguish changes in the bronchi in the above diseases. Chronic pneumonia is characterized by an unusual picture. Changes in the bronchi in the infiltration zone are not uniform, their contours are uneven, the areas of narrowing and widening are of different sizes. In congenital bronchiectasis, on the contrary, the radiographs of different patients seem to copy each other. Cystic bronchiectasis causes multiple thin-walled cavities that do not contain fluid. The lung tissue to the periphery of the cavities is underdeveloped, without foci of infiltration, the pulmonary pattern is depleted ("cystic hypoplasia of the lung"). In dysontogenetic bronchiectasis, part of the lung is underdeveloped and reduced (for example, the entire lower lobe). The bronchi in it are collected in a bundle, equally dilated and ending in club-shaped swellings.

Pneumoconiosis

With the modern development of industrial and agricultural production, the problem of prevention and early recognition of dust-induced lung diseases - pneumoconiosis - has acquired exceptional importance.

The main role here is undoubtedly played by X-ray examination. Of course, diagnostics is based primarily on data about the patient's long-term work in conditions of increased content of inorganic and organic dust in the air, but anamnestic information is not always helpful.

The professional experience may be short, and the reliability of dust control measures at work may be insufficient. Even more insidious are cases when a worker in a dusty profession develops not pneumoconiosis or not only pneumoconiosis, but also another disseminated lung lesion. Clinical manifestations of pneumoconiosis in the early stages are scanty.

Early, as well as all subsequent, diagnostics of pneumoconiosis is based on the results of high-quality X-ray images. Depending on the nature of the dust and the reactivity of the patient's body, the first noticeable symptoms are expressed mainly in interstitial or focal changes, therefore, three types of the disease are distinguished: interstitial, nodular and nodular.

The interstitial type initially manifests itself as a delicate mesh of the pulmonary pattern in the root zones. Gradually, the compaction of the interstitial tissue and, accordingly, the restructuring of the pulmonary pattern spreads across the pulmonary fields with some tendency to spare the tops and bases of the lungs. However, with asbestosis and talcosis, the mesh of the pattern is observed mainly in the lower sections. Focal formations are absent with asbestosis, but pleural layers appear, sometimes powerful, in which there may be lime deposits. Interstitial changes predominate in grinders' pneumoconiosis, aluminosis, inhalation of tungsten and cobalt dust, anthracosis.

The expanded picture of silicosis and miners' pneumoconiosis is characterized by the presence of multiple foci against the background of diffuse reticular fibrosis, i.e. a nodular type of the disease is observed. Pneumoconiotic nodules are caused by the proliferation of connective tissue around dust particles. The sizes of the foci vary - from 1 to 10 mm, the shape is irregular, the outlines are uneven, but sharp. They are more densely located in the middle and lower sections. The roots of the lungs are enlarged, fibrously compacted, they may have enlarged lymph nodes (the marginal, shell-like calcification of such nodes is very indicative). The peripheral parts of the lungs are swollen. Signs of increased pressure in the pulmonary circulation are the expansion of large branches of the pulmonary artery, small sizes of the cardiac shadow, hypertrophy of the right ventricular muscle, deepening of its contractions. Further progression of the disease leads to the formation of large fibrous fields and areas of compaction (large darkening). This is a nodular type of lesion. Its recognition is not difficult. It is only necessary to exclude the frequently observed combination of conglomerate pneumoconiosis with pulmonary tuberculosis.

Pulmonary tuberculosis

All measures to combat tuberculosis are based on the principle of preventing infection and early detection of the disease. The goals of early detection are screening fluorographic examinations of various contingents of the healthy population, as well as correct and timely diagnosis of tuberculosis in outpatient clinics, polyclinics and hospitals of the general medical network. In accordance with this classification, the following forms of tuberculosis of the respiratory organs are distinguished.

Primary tuberculosis complex. Tuberculosis of the intrathoracic lymph nodes. Disseminated pulmonary tuberculosis. Miliary pulmonary tuberculosis. Focal pulmonary tuberculosis. Infiltrative pulmonary tuberculosis. Caseous pneumonia. Tuberculoma of the lungs. Cavernous pulmonary tuberculosis. Fibro-cavernous pulmonary tuberculosis. Tuberculous pleurisy (including empyema). Tuberculosis of the upper respiratory tract, trachea, bronchi, etc. Tuberculosis of the respiratory organs, combined with dust diseases of the lungs.

There are two phases in the course of tuberculosis:

• infiltration, decay, seeding;
• resorption, compaction, scarring, calcification.

As can be seen, the clinical classification of pulmonary tuberculosis is based on morphological data revealed by X-ray examination.

Primary complex.

The objectives of radiological examination in the examination of patients with pulmonary tuberculosis:

• 1) establish the presence of a tuberculous process in the lungs;
• 2) characterize morphological changes in the lungs and intrathoracic lymph nodes;
• 3) determine the form and phase of the disease;
• 4) monitor the dynamics of the process and the effectiveness of therapy.

Primary tuberculosis complex - focal or lobular pneumonia, usually located subpleurally. Narrow stripes of lymphangitis extend from it to the root of the lung. Enlarged lymph nodes are determined in the root - a characteristic sign of primary tuberculosis. The shadow visible in the images in the pulmonary field consists of a central cheesy area and a perifocal zone, which is caused by serous-lymphocytic impregnation of tissues. Under the influence of specific therapy, the perifocal zone decreases by the end of the 3-4th week and resolves in 3-4 months. The lymph nodes gradually decrease and become denser. Within 2-3 years, lime salts are deposited in the pulmonary focus and lymph nodes. The calcified primary focus is called Ghon's focus. It is detected during screening X-ray studies in 10-15% of healthy people.

Tuberculosis of the intrathoracic lymph nodes is the main form of intrathoracic tuberculosis observed in childhood. X-rays show enlargement of one or both pulmonary roots and loss of differentiation of their shadow. In some cases, enlarged lymph nodes are visible in the root, in others, their outlines are lost in the shadow of perifocal infiltration. Tomography, especially computer tomography, helps to detect hyperplasia of the lymph nodes. As the disease heals, the nodes decrease in size, and fibrous changes remain in the root.

Disseminated pulmonary tuberculosis occurs in various forms (miliary, acute and chronic disseminated), and the dissemination of foci can occur by hematogenous or bronchogenic routes.

In acute hematogenous disseminated tuberculosis, multiple uniformly distributed focal shadows of the same type are determined in the pulmonary fields. The lungs are moderately swollen, but their transparency is reduced, and the pulmonary pattern is partially hidden behind the focal rash.

Chronic hematogenous disseminated tuberculosis is characterized by a wave-like course with repeated rash and partial resorption of foci. It is characterized by bilateral lesions of the apices and dorsal sections of the upper lobes. The foci vary in size, are multiple, and are usually productive. They are located against the background of an enhanced pulmonary pattern (due to fibrosis). The fusion of foci and their disintegration lead to the emergence of thin-walled caverns. They serve as a source of bronchogenic seeding - the appearance of acinous or lobular foci of compaction of lung tissue in the middle and lower sections of the lungs.

Focal tuberculosis is actually a composite group of tuberculous lesions of the lungs of the post-primary period, which differ in genesis. Their distinctive feature is the presence of unevenly and asymmetrically located foci of different shapes and sizes, mainly in the apices and subclavian parts of the pulmonary fields. On the anterior radiograph, the total extent of the lesion should not exceed the width of two intercostal spaces (not counting the apices), otherwise we speak not of a focal process, but of a disseminated process.

Infiltrative pulmonary tuberculosis is displayed on radiographs as a typical limited darkening of the lung field. The substrate of the darkening is perifocal inflammation around a newly formed or exacerbated old tuberculous lesion. The extent and shape of the darkening vary widely: sometimes it is a round focus in the subclavian zone, sometimes a large cloud-like shadow corresponding to some subsegment or segment, sometimes infiltration of the lung tissue near the interlobar fissure (the so-called periscissuritis: from "scissura" - interlobar fissure). The dynamics of the infiltrate is different. In favorable cases, the perifocal inflammation is completely absorbed, and the caseous center is compacted. A small fibrous field or compacted lesion remains on the images, but melting of the infiltrate with the formation of a cavern is observed. Sometimes the entire infiltrate undergoes caseous degeneration, is encapsulated and turns into a tuberculoma.

Caseous pneumonia is a severe form of tuberculosis. It is characterized by infiltration of an entire lobe of the lung with rapidly developing caseous decay and formation of cavities or the appearance of multiple lobular foci, also prone to fusion and decay.

Pulmonary tuberculoma is one of the variants of progression of a pulmonary focus or infiltrate. On radiographs, a round, oval or not quite regular shadow with sharp and slightly uneven contours is revealed. The shadow is intense, sometimes lighter areas of decay of a crescent shape or denser inclusions - lime deposits - stand out in it. In the lung tissue around the tuberculoma or at a distance from it, shadows of tuberculous foci and post-tuberculous scars can be seen, which helps in differential diagnostics with primary lung cancer.

Cavernous pulmonary tuberculosis occurs as a result of the disintegration of lung tissue in any form of tuberculosis. Its characteristic radiographic sign is the presence of a ring-shaped shadow in the pulmonary field. Sometimes the cavern is clearly visible on survey or targeted radiographs. In other cases, it is poorly distinguishable among the shadow of tuberculous foci and sclerosis of the lung tissue. In these cases, tomography helps. In fresh cavernous tuberculosis, sclerotic phenomena are usually insignificant, but later on, wrinkling of the affected areas occurs, which are penetrated by rough cords and contain numerous tuberculous foci: the process passes into the cirrhosis phase.

Cirrhotic pulmonary tuberculosis is the final stage of tuberculosis progression, accompanied by the disintegration of lung tissue. The affected part of the lung, most often the upper lobe, is sharply reduced and sclerotic. Its shadow on the images is non-uniform due to a combination of sclerotic areas, deformed tuberculous cavities, dense foci, and individual swellings of the lung tissue. The mediastinal organs are displaced toward the affected side, the intercostal spaces are narrowed, there are pleural layers, and the adjacent parts of the lungs are swollen.

Primary lung cancer

Primary lung cancer in the early stages of development does not produce distinct subjective symptoms and a clear clinical picture. The discrepancy between the clinical manifestations of the disease and the anatomical changes is the reason why the patient does not consult a doctor. There should be an obstacle on the path of the disease - a mass examination of the population using fluorography or radiography. The contingents that most often develop lung cancer are subject to annual examination: male smokers over 45 years old and people suffering from chronic lung diseases. In all patients who have changes in the lungs on fluorograms or radiographs, it is necessary to first exclude cancer.

The main methods of X-ray diagnostics of primary lung cancer are X-ray of the lungs in two projections with high voltage on the tube and tomography or CT of the lungs. With their help, both main forms of cancer can be detected - central and peripheral.

Central cancer originates from the epithelium of the segmental, lobar or main bronchus. In the early phase, the tumor image is difficult to notice due to its small size and a large number of shadows in the root of the lung, therefore, in case of minor hemoptysis of unclear origin or unexplained cough persisting for more than 3 weeks, a bronchological examination is indicated. Then, with predominantly endobronchial tumor growth, symptoms of impaired ventilation and blood flow appear in the segment or lobe associated with the bronchus, the lumen of which is narrowed by the tumor. The radiographic picture of these disorders - hypoventilation, obstructive emphysema and, finally, atelectasis - is described above. In these cases, tomography or CT is performed. The slightest narrowing of the bronchus, unevenness of its contours, an additional shadow in the lumen confirm the assumption of a tumor process.

With predominantly exobronchial tumor growth and local thickening of the bronchial wall, the shadow on tomograms appears relatively early, and then, when its size exceeds 1-1.5 cm, it becomes noticeable on radiographs. Similar signs are observed in peribronchial nodular cancer. On the contrary, in branched peribronchial cancer, the image of the tumor node is absent. In the root zone, an area of an enhanced pattern is determined, consisting of tortuous stripes radially diverging into the pulmonary field and accompanying vascular-bronchial branches. The root shadow is poorly differentiated. Narrowing of the lumen of the lobar or segmental bronchus and the branches extending from it can be seen on tomograms. Scintigraphy reveals a distinct disruption of blood flow in the pulmonary field. Ultimately, with all variants of central cancer growth, atelectasis of the segment, lobe, or the entire lung occurs.

The radiographic expression of small peripheral cancer is a single lesion in the lung. Its features are as follows:

1. small size (the limit of visibility on a fluorogram is 4-5 mm, on an X-ray 3 mm);
2. low intensity of the shadow (even with a diameter of 10-15 mm, this shadow is weaker than the shadow of a tuberculoma or benign tumor);
3. round shape; less common are also shadows of a triangular, diamond-shaped and star-shaped form;
4. relatively blurry contours (also in comparison with the shadow of a cyst or benign tumor).

Calcific inclusions are rare, occurring in only 1% of peripheral cancer cases.

As the tumor grows, its shadow becomes more rounded, but its edges are more scalloped or simply bumpy, which is clearly visible on linear and computer tomograms. Also characteristic are more pronounced unevenness in any one area and retraction on the contour in the place where the bronchus enters the tumor. The tumor shadow is non-uniform, which is explained by the bumpiness of its surface. In the case of decay, clearings appear in the tumor shadow. They can look like two or three small cavities or one large marginal or centrally located cavity. The so-called cavitary form of cancer is also known, when a round cavity resembling a cavern or cyst appears on the images. Its cancerous nature is revealed by the unevenness of the inner surface and a bumpy thickening on a limited area of one of the walls of the cavity (the "ring with a ring" symptom). With tumors with a diameter of more than 3 - 4 cm, "paths" to the pleura and the root of the lung are often determined.

With radiographs taken at different times, it is possible to establish the approximate rate of tumor growth. In general, the time it takes for the tumor to double in size varies from 45 to 450 days. In elderly people, the tumor can grow very slowly, so that its shadow sometimes hardly changes for 6-12 months.

CT provides valuable information. It allows to specify the extent of central cancer, its growth into the mediastinal organs, the condition of the intrathoracic lymph nodes, the presence of effusion in the pleural and pericardial cavities. In case of a peripheral node in the lung, CT allows to exclude benign tumors containing areas of fat or ossification (in particular, hamartomas). The density of a cancerous node exceeds 60 HU, but if it is more than 140 HU, then it is usually a benign tumor. Tomograms very clearly show the growth of peripheral cancer into the rib. In addition, cancer nodules are detected that are not easy to notice on conventional images (in the perimediastinal or marginal subpleural zones).

An auxiliary method in the diagnosis of lung cancer and its metastases in the lymph nodes of the mediastinum is scintigraphy with gallium citrate. This radiopharmaceutical has the ability to accumulate both in cancer nodes and in lymphoid tissue clusters in lymphogranulomatosis, lymphosarcoma, and lymphocytic leukemia. The property of concentrating in a cancerous lung tumor is also possessed by the technetium preparation - 99mTc-sesamibi.

In almost all cases of operable cancer, it is necessary to perform a bronchoscopy or transthoracic puncture to obtain a piece of tissue for microscopic examination. Under the control of television fluoroscopy, it is possible to puncture most pulmonary and mediastinal formations, but in some cases, when it is difficult to hit a small "target" and choose the optimal trajectory of the needle, the puncture is performed under CT control. A thin biopsy needle is inserted along a linear cursor. Several cuts are used to establish that the tip of the needle is in the correct position.

Many malignant tumors (lung cancer, breast cancer, seminoma, osteogenic sarcoma, etc.) tend to metastasize to the lungs. The picture is quite typical when several or many round tumor nodules are detected in the lungs. It is more difficult to diagnose cancerous lymphangitis, when tortuous stripes seem to penetrate the lower parts of the lung fields. This lesion is especially characteristic of metastasis to the lungs of gastric cancer.

Diffuse (disseminated) lung lesions

Diffuse (disseminated) lung lesions are understood as widespread changes in both lungs in the form of scattered lesions, an increase in the volume of interstitial tissue, or a combination of these conditions.

Commonly observed focal lesions include all forms of disseminated tuberculosis, pulmonary carcinomatosis, acute bronchiolitis, and childhood infections.

Radiographs, linear and computer tomograms reveal multiple foci of the same type or different calibers in both lungs. Depending on the size of the foci, a distinction is made between miliary seeding (foci 0.5-2 mm in size), small focal (2-4 mm), medium focal (4-8 mm) and large focal (more than 8 mm).

The increase in the volume of interstitial tissue of the lungs is expressed on radiographs by an increase in the pulmonary pattern, which takes the form of a delicate or coarser mesh. This mesh reorganization of the lung structure is most often detected on computed tomograms. They allow one to judge the state of the interlobular septa, the presence of peribronchial compactions, exudate in the alveolar tissue, lobular emphysema, and small granulomatous nodules. Frequently detected mesh-nodular lesions include pneumoconiosis, sarcoidosis, exogenous and endogenous allergic alveolitis, toxic alveolitis, drug disease, cancerous lymphangitis, and all forms of idiopathic fibrosing alveolitis, including Hamman-Rich syndrome.

The nature of diffuse damage cannot be determined in all cases based on radiographic data. Comparison of the results of the patient's survey and examination, radiation studies (radiography, CT, gallium citrate scintigraphy), bronchoalveolar lavage, and immunological tests is of decisive importance.

Pleurisy

The pleural cavity of a healthy person contains 3-5 ml of "lubricating" fluid. This amount is not detected by radiation methods. When the volume of fluid increases to 15-20 ml, it can be detected using ultrasound. In this case, the patient should be in a lying position on the sore side: then the fluid will accumulate in the lowest (outer) section of the pleural cavity, where it is determined.

A small amount of free pleural fluid is detected in the same way during radiography, taking pictures with the patient lying on his side (laterography) during exhalation. With further accumulation of fluid, its radiographic diagnosis is not difficult.

Any free pleural effusion on X-rays taken in a direct projection with the patient in an upright position causes an intense shadow in the lower outer part of the lung field of approximately triangular shape. The shadow is adjacent to the ribs and diaphragm on two sides, and descends from the lateral part of the chest towards the diaphragm at the top. The upper border is not sharp, since the fluid layer gradually becomes thinner upward. As the effusion accumulates, the size and intensity of the shadow increase. When the upper border of the effusion is at the level of the lateral part of the body of the 5th rib, its amount is equal to 1 liter on average, at the level of the 4th rib - 1.5 liters, the 3rd rib - 2 liters. The greater the effusion, the more the mediastinal organs are displaced to the opposite side.

In the presence of adhesions dividing the pleural cavity into separate chambers, limited (encapsulated) effusions are formed. Sealed in the pleural sheets, they do not move when the body position changes and are slowly absorbed. The boundaries of the shadow with encapsulated effusion become sharp and convex. The shape and position of the shadow are determined by the place of encapsulation of the fluid - near the ribs (costal effusion), between the diaphragm and the base of the lung (diaphragmatic), near the mediastinum (mediastinal), in the interlobar fissure (interlobar).

Space-occupying lesions in the mediastinum

In the mediastinum, various cystic, tumor and tumor-like formations are detected, mainly during X-ray examination of the chest organs. X-ray and CT usually allow to specify the location of the pathological formation, which in itself is very important for diagnosis.

The anterior mediastinum is predominantly localized with retrosternal goiter, thymoma, teratomas, ascending aortic aneurysm, and packets of enlarged lymph nodes. Enlarged lymph nodes may also be located in the middle section of the mediastinum. An aortic arch aneurysm and a bronchogenic cyst may also be detected there. Neurogenic tumors and cysts, enterogenic cysts, and aneurysm of the descending thoracic aorta are found in the posterior mediastinum. In addition, part of the stomach penetrates into the posterior mediastinum in the case of a hernia of the esophageal opening of the diaphragm.

Differential diagnosis of all these numerous lesions is based on anamnesis data, clinical examination results, laboratory tests and, of course, radiological studies and biopsies. Let us point out the main points. CT and MRI easily identify aneurysms of the aorta and other large vessels. The same methods and ultrasound examination allow us to establish the tissue structure of the formation and thereby diagnose cysts filled with fluid and teratomas including fat or bone elements. If a retrosternal or intrasternal goiter is suspected, it is advisable to begin the examination with scintigraphy with ^99m Tc-pertechnetate or radioactive iodine, which accumulate in the thyroid gland. As for lymphadenopathy, its nature is determined based on anamnesis data and the results of clinical and laboratory research. Lymphadenopathy in adults is most often caused by diseases such as lymphomas (including lymphocytic leukemia), sarcoidosis and cancer metastases, and less often by tuberculosis and infectious mononucleosis.

Currently, ultrasound-guided puncture biopsies or CT or X-ray television-guided puncture biopsies are widely used to establish a definitive diagnosis.

Intensive care and interventional procedures under the control of radiological methods

As noted above, sonography, X-ray television, CT and MRI are widely used as methods of guidance and control in puncture biopsy of pulmonary and mediastinal formations, as well as for drainage of abscesses and empyemas of the pleura. In case of hemoptysis and bleeding, embolization of the corresponding bronchial artery is performed. Embolization of pulmonary vessels is used to treat arteriovenous malformations in the lungs.

Radiation control is necessary during vascular catheterization, in particular to establish the position of the central venous catheter and to exclude extraluminal spread of the solution. Insertion of a catheter into the subclavian vein is sometimes accompanied by the development of pneumothorax or mediastinal hematoma. These complications are recognized by radiography. To detect a small pneumothorax, a lung image is taken during deep exhalation. The position of the catheter (probe) is also recorded when measuring the central venous pressure in the pulmonary artery.

Pulmonary complications are observed after various surgical procedures. In the intensive care unit, the radiologist usually has to differentiate four pathological conditions of the lungs: edema, atelectasis, pneumonia and aspiration. Manifestations of interstitial edema resemble the picture of venous congestion in the lungs, alveolar edema causes poorly defined "darkening" in the lung fields, especially in the hilar zones and lower sections. Collapse of a lobe or segment can result from postoperative collapse, retention of secretions in the bronchial tree or aspiration. Discoid or lamellar atelectases have the form of narrow stripes crossing the lung fields mainly in the supradiaphragmatic zones. Aspiration of gastric contents leads to the appearance of focal shadows of varying sizes in the lower sections of the lungs.

After trauma and major operations, a disorder of microcirculation in the lungs sometimes occurs with a picture of the so-called respiratory distress syndrome ("shock lung"). Beginning with interstitial edema, it then causes large areas of alveolar edema.

After the lung is removed, a drainage tube is visible on X-rays, lying in an empty pleural cavity. This cavity gradually fills with fluid, and hydropneumothorax is detected during X-ray examination. As the fluid is absorbed, pleural adhesions form and fibrothorax is formed.

During the first day after lung transplantation, pulmonary edema occurs. It resolves in the next 2-3 days. Delayed or increasing edema resolution gives grounds to suspect acute lung rejection. In this case, pleural effusion is also observed. A severe complication is stenosis of the vascular-bronchial anastomosis, which can lead to necrosis of its wall, in connection with which many patients require dilation and stenting of the narrowed area. Almost half of patients after lung transplantation experience infectious complications - bronchitis, pneumonia. A formidable symptom of possible chronic lung rejection is the development of constrictive bronchiolitis, which is accompanied by atelectasis, the development of bronchiectasis and areas of fibrosis. It is determined using CT 3 months after transplantation.