After a lung examination, the report showed that there was a shadow in the lungs, and there must be many people who would immediately get nervous and worry about whether they had lung cancer.
In fact, the shadow of the lungs X-ray and CT examination is a common condition of many lung diseases, and the shadows shown by different diseases often have their own characteristics.
01 Normal
To know what is wrong with the shadow of the lungs, we need to first understand the normal situation.
First of all, let's talk about the anatomy of the lungs, our lungs are divided into two parts, the left lung is divided into two parts, the left lung is divided into upper and lower lobes, and the right lung is divided into upper, middle, and lower lobes, and each lobe can be further subdivided into multiple small lung segments.
Between the two lungs, the trachea is distributed, and the trachea divides the left and right main bronchi to the left and right lungs, and then continues to divide the lobes and segments of the bronchi downwards.
These trachea are interspersed in the lungs to form a tree-shaped bronchial network that allows the lungs to exchange gases.
At the end of the trachea are many alveoli, so the lung tissue is not solid, but there are many voids like a sponge, which are elastic.
In general, the higher the tissue density and the more rays are absorbed, the more "white" the image presented in X-rays or CT.
Therefore, under normal circumstances, the lung tissue is generally more uniform gray-black, dark black image, if the lung tissue inflammation, fibrosis, calcification, nodules, tumors, it may appear gray or even white images.
02 Diffuse patchy opacities in the lungs, common in pneumonia
Pneumonia is often caused by infections such as bacteria and viruses. After the infection of the lungs, the lung tissue may produce some inflammatory exudation, and the white blood cells will gather to help eliminate inflammation, which may change the density of the lung tissue, thus showing a large "whitish" shadow in X-rays and CT examinations.
Viral pneumonia (such as new crown pneumonia) and bacterial pneumonia (such as lobar pneumonia caused by Streptococcus pneumoniae pneumoniae) can show different characteristics in X-ray examination:
The virus may invade more lung tissue, and several lung segments and lobes may be infected, so from the shadowed area, viral pneumonia may be more extensive.
From the density of shadows, the density of bacterial pneumonia (such as lobar pneumonia) will be relatively higher, that is, a certain area on the map may be "whiter".
Of course, if the diagnosis is to be finalized, it is still necessary to carry out sputum culture or blood tests and other tests, and you cannot rely only on images to make judgments.
03 Dumbbell-shaped shadows can be seen in early tuberculosis
After the development of tuberculosis, a local lesion will appear in the lungs, which may cause lymphangitis in the corresponding area, and inflammation may spread along the lymphatic vessels to the lymph nodes.
Thus, lesions in the lungs, lymph nodes, and lymphatic vessels that are intermediately connected will present a dumbbell-shaped shadow in the X-ray, which is often typical of early tuberculosis.
Of course, the infection of tuberculosis is often not limited to the local, in addition to a large main lesion, there may be other small infection foci around, then if the CT examination, you can observe a satellite-like shadow, that is, "satellite foci".
In addition to this, since tuberculosis tends to calcifile tissues, some "very white" calcification shadows can also be observed in CT.
Tuberculosis bacteria constantly destroy tissues, and can also form some marginal rough, insect bite-like cavities, medically known as "insect erosion-like cavities".
04 Flat shadow containing air fluid can be seen in lung abscesses
A flat shadow containing gas is a shadow containing a plane of gas and liquid.
This is due to the fact that after the tissue dies of necrosis, it will become a liquid substance, which is discharged from the body little by little through the airway, but sometimes a part of the necrotic tissue has not been discharged, and then standing up to do X-ray examination can show that the upper is gas, and the lower part is the gas-containing liquid flat shadow of the liquid.
Flat shadows containing gas are common in lung abscesses, and the resulting hollow walls are often smooth and regular, and the shadow density is often lighter, which can be distinguished from tuberculosis.
05 Irregularly dilated shadows can be seen in lung cancer
In addition to tuberculosis and lung abscesses, lung cancer can also cause tissue necrosis and form cavities.
However, the cavity of lung cancer is usually caused by abnormal cell proliferation, when the hyperplasia reaches a certain extent, there are no blood vessels in the center, the tissue is necrotic, and the necrotic tissue will form an irregular cavity after discharge, and it is often an eccentric cavity.
In addition, tumor tissue will penetrate into the surrounding tissues to compete for nutrition, so in X-ray or CT images, you can also see the manifestations of dilated growth and burrs.
Of course, different types of lung cancer will have their own different manifestations.
References: Medical Microvision official website - Zhao Liqiang, Chief Physician, "Differential Diagnosis of Lung Shadow"