Pulmonary nodules are basically detected by imaging, and small pulmonary nodules <2 cm are mainly detected by CT examination. Therefore, pulmonary nodules should have been diagnosed by the radiology department (imaging department) and then referred to the relevant departments for treatment. Unfortunately, at present, radiologists in many hospitals do not make a clear and definite diagnosis of pulmonary nodules, and the diagnostic reports are often ambiguous, causing panic among patients and their families. When some surgeons see such reports, they believe that the radiologist has not excluded malignancy as an indication for surgery and give surgery to remove the nodule. ". When some medical or oncologists see such reports, they may treat the patient with chemotherapy or radiotherapy, causing serious physical and psychological damage to the patient; some lung nodules are originally lung cancer, but because they are not clearly diagnosed and followed up, early lesions are delayed until late, depriving the patient of treatment opportunities. Why do radiologists not make a definite diagnosis? The main reasons are: ① Objectively, the differential diagnosis of lung nodules is quite difficult. There are many types of pulmonary nodules, and all types of pulmonary nodules behave very similarly, so it is not easy to distinguish them. ② At present, doctors are basically promoted and promoted by doing scientific research, writing papers, which must also be published in foreign journals, so the main focus of doctors are learning foreign languages and doing research. Over time, there are fewer and fewer doctors who can see patients. ③The concept of emphasizing treatment over diagnosis still plays a major role. For example, diagnostic charges are getting lower and lower, with Shanghai charging only 170 RMB for CT, making it possible for hospitals to perform only the simplest scans on patients and to make a clear diagnosis of small nodules in the lungs at all. ④ Forced by the medical environment. Because even the most experienced radiologists cannot always be good at diagnosis, and in China, medical disputes can arise once a diagnosis is determined to be wrong, giving an inconclusive diagnosis is both less work and safer. The population at risk for lung cancer in China differs from that in Western countries in that there is a small difference in lung cancer incidence between smokers and nonsmokers, and between men and women. Lung nodules (especially small lung nodules) basically have no conscious symptoms and are mainly detected by physical examination or screening. So who is screened? High-risk groups. Who are the high-risk groups? In Western countries, the high-risk group for lung cancer is heavy long-term smokers, as calculated by the formula. In developed Western countries, the difference in lung cancer incidence rates between smokers and non-smokers, and between men and women, is so great that smokers are considered to be a high-risk group for lung cancer. In China, however, the difference in lung cancer incidence rates between smokers and nonsmokers, and between men and women is small, even among nonsmokers and women, for the following reasons. (1) Non-smokers are basically passive smokers because people smoke in the workplace and many public places; (2) Air pollution, everyone is living in the haze, everyone is inhaling PM2.5, and Chinese women are also subject to the hazards of kitchen fumes, so I suggest that people over 40 years old, regardless of gender and whether they smoke or not, should be targeted for lung cancer screening. What tools are used for screening? Nowadays, medical examination centers still use chest X-ray to screen for lung cancer, which is the main reason for a large number of missed and misdiagnosed lung cancer. Lung cancers that are screened for ground glass nodules (GGO) with chest radiographs are missed in their entirety, as are small lung cancers that are soft tissue nodules (solid nodules) in a significant percentage of patients. Therefore, screening for lung cancer with chest radiographs must be stopped immediately, and the basic tool for screening for lung cancer should only be CT or low-dose CT examinations. A definitive diagnosis of lung nodules should be made whenever possible The kind of management that sees lung nodules without a definitive diagnosis and then operates randomly is irresponsible. Pulmonary nodules found on CT can be benign or malignant, with benign nodules being the majority. Many benign nodules do not require treatment, whereas malignant pulmonary nodules must be treated as soon as possible. Therefore, a definitive diagnosis must be made when a pulmonary nodule is found. If a benign nodule is misdiagnosed as malignant, the patient may suffer a "wasted stab" or receive chemotherapy and/or radiation therapy by mistake, which can severely damage the body. If a malignant nodule is misdiagnosed as benign, the disease can be delayed, even from early to late stages, and the opportunity for treatment can be lost. We have the ability to make a definitive diagnosis of most pulmonary nodules because different pulmonary nodules grow in different ways and take on different forms, just as each person has a different look, and we can always find out the difference between them if we examine them carefully and analyze them carefully. However, these benign and malignant signs are very subtle, and it is necessary to adjust the scan parameters for each patient's different situation, to perform meticulous computerized post-processing, and to carefully observe the morphology, margins, internal structure, small airways, small blood vessels, and changes in surrounding structures of the lesion before it is possible to make a distinction. It is irresponsible to manage a lung nodule without a clear diagnosis. Follow-up of pulmonary nodules In patients with pulmonary nodules, we should make a clear diagnosis as soon as possible. If the nodule is definitely malignant, we recommend treatment as soon as possible. There is no uniform guideline in China on what kind of pulmonary nodules need to be followed up and how to follow up, but there is one in foreign countries. We do not reject what comes from abroad, and we can learn from it, but we do not believe in it or copy it. For example, the Fleischner guidelines in the United States have six articles, one of which is not to treat nodules <5 mm, and the other five are to review them after 3 months, which is obviously not suitable for our national situation. In the author's opinion, for patients with pulmonary nodules, we should all make a clear diagnosis as soon as possible and advise them to treat them as soon as possible if they are definitely malignant and tell them to free themselves from panic as soon as possible if they are definitely benign. For those who cannot be diagnosed clearly by imaging, we can suggest minimally invasive examinations such as tracheoscopy, percutaneous puncture or thoracoscopy, which can make a clear diagnosis in about 1 week, and for those who still cannot make a clear diagnosis, they need to be followed up. We must also have a tendency opinion about the patients who need follow-up. If the tendency is for infectious lesions, anti-infective treatment and short-term review (2-4 weeks) can be given; if the tendency is for benign lesions such as benign tumors and sarcoidosis, long interval follow-ups of six months or more can be scheduled. Proper view of X-rays X-rays less than 100msv have no effect on human body. X-rays are used to diagnose diseases in X-ray examinations and CT examinations. You can often find articles about the hazards of X-rays, which makes some people afraid to come to the hospital for examinations. X-rays are invisible rays that can diagnose and treat diseases in small amounts, but can cause damage or even death in large amounts. How much is harmless and how much is harmful? Research shows that less than 100msv has no effect on the human body. 1 course of radiation therapy dose at least 2000msv, 1 low-dose CT radiation dose is about 1ms.