The treatment of lung cancer has made great progress, but the prognosis of lung cancer patients has not improved significantly, and the 5-year survival rate is only 10%-15%. The main reason for this is that the early diagnosis rate of lung cancer is only 15%. The prognosis of lung cancer is closely related to the clinical stage at the time of diagnosis: the 5-year survival rate of stage 0 lung cancer patients can reach more than 90%, 60% for stage I, and decreases from 40% to less than 5% for stage I-IV patients. Among patients who present with symptoms, 80% of them are already in stage III or IV and lose the opportunity of surgery. Therefore, improving the early diagnosis of lung cancer is the key to improving the 5-year survival rate of lung cancer. I. Clinical manifestations Early diagnosis of lung cancer should pay attention to the changes of symptoms and new respiratory symptoms. The common symptoms of lung cancer include cough, hemoptysis, chest pain, dyspnea, weight loss, fatigue, fever, etc.. And cough and dyspnea are the most common symptoms . The patient had more than one new symptom before the diagnosis, and their new symptoms cannot be explained by the aggravation of the disease alone. Therefore, the identification of early symptoms of lung cancer is helpful to improve the survival rate of patients. The development of imaging provides powerful tools for early diagnosis of lung cancer. At present, the main imaging examination methods are chest X-ray, CT (SCT, HRCT, CTVB), MRI and PET-CT. The most promising one is low-dose CT. New methods of minimally invasive interventional examination 1. Transbronchoscopic biopsy (TBB) has a positive rate of more than 95% for biopsy + brush smear of tumors in the airway. 2. Transbronchoscopic lung biopsy (TBLB) is suitable for extrapulmonary peripheral lesions, with a positive rate of 40% to 80%, and a positive correlation between the positive rate and the size of the lesion. Transbronchial wall needle aspiration biopsy (TBNA) is suitable for bronchial mucosal lesions and extrabronchial pressure lesions (including hilar and mediastinal lymph nodes), peripheral isolated pulmonary nodules, etc., and its positive rate can reach about 70%. 3.Fluoroscopy or laser-excited fluorescence endoscopy (FPE or LIFE) uses blue light of wavelength 400~440 mm to produce light red fluorescence for pre-cancerous and in situ cancer, and green light for normal tissues to target lesion biopsy. Therefore, it is suitable for the diagnosis of precancerous and in situ cancer, and its diagnostic rate is 1.5-6.3 times higher than that of ordinary fibrinoscopy. In addition, it is very useful for infiltrating carcinoma and occult lung cancer, which is located in the proximal bronchus. Therefore, this test is suitable for suspected central lung cancer and applied to the specific group of people with high risk of lung cancer, imaging examination (a), but the specificity of diagnosis is only 33% for those with suspicious sputum examination, which is not suitable for lung cancer screening. The sensitivity of conventional TBB followed by fluorescence fibrinoscopy is 61.2% for fluorescence fibrinoscopy and 10.6% for conventional fibrinoscopy. 4.Ultrasound bronchoscopy (EUB) Intraluminal ultrasound can show the structure of bronchial wall and extravasation and lymph nodes, and its greatest value is to improve the positive rate of transbronchial wall needle aspiration biopsy. In order to improve the diagnostic rate, the current ciliofibroscopy cannot achieve the above-mentioned purpose, and it is necessary to adopt a special ciliofibroscope with a new ciliofibroscope equipped with a convex and Doppler probe at the distal end, which has a sensitivity of 95.7%, a specificity of 100%, and an accuracy of 97%. It is often used for needle aspiration biopsy of mediastinal or hilar lymph nodes. 5, simulation bronchoscopy (CTVB) under its guidance for ultra-fine bronchoscopic biopsy, ultra-fine bronchoscopy can enter the 5th-8th level bronchi, the outside diameter of the mirror 2.8 mm, biopsy tube diameter of I.2 mm, suitable for the diagnosis of unknown small peripheral type of lung lesions (diameter of about 1 ~ 2 mm). Currently, the use of navigation and guidance for transbronchial biopsy using ultra-fine bronchoscopy or the addition of targeting or local thin-layer high-resolution target reconstruction after lesion detection by application of examination is beneficial to improve the early diagnosis rate of lung cancer. 6. Television thoracoscopy (VATS) examination is helpful for biopsy or resection of peripheral lung lesions, mediastinal lymph nodes and pleural lesions taken from the periphery. Recently, it has been reported that the ultra-fine bronchoscope is placed in the target bronchus under direct vision using simulated bronchoscopic navigation, and a guide wire is placed through the bronchoscope with the aid of CT and x-ray fluoroscopy, and barium sulfate solution is dripped for contrast (4-9 levels of bronchus can be shown), and then thoracoscopic surgery is performed, which is suitable for the diagnosis of small lung lesions (≤10 mm). 7, electromagnetic navigation system through the bronchoscope on the peripheral lung lesion biopsy has been reported that the use of previous diagnostic means of peripheral nodular foci, especially the outer 1/3 of the lung with small nodular foci, diameter < 2 c / n diagnosis is still very limited, the new application of electromagnetic navigation system is expected to solve this problem. The main components of the electromagnetic navigation system are a magnetic plate, a microsensor and a monitoring computer system. The patient is placed on the magnetic plate (the whole chest is in a weak magnetic field) and a special curved catheter with a microsensor at the head end is inserted into the bronchial lumen through the bronchoscopic biopsy hole. guide the catheter to the site of the lesion for puncture biopsy. 8.Transthoracic wall needle aspiration biopsy (PTNB) has a positive rate of 85-90% and a false negative rate of 10-15%. The key to improve the positive rate of transthoracic lung biopsy for small peripheral lung cancer nodules ≤2 cm lies in: ① absolutely correct localization; ② generally adopt fine needle aspiration biopsy; ③ proficiency of puncture technique; ④ pathology technique needs to be further improved, direct on-site smear is about 3 times higher than the positive rate after fixation of the specimen in 95% alcohol. The hit rate of transthoracic wall lung biopsy for small peripheral pulmonary nodules ≤2 cm in our department, avoiding the obstruction of the rib cage, and using fluoroscopy under real-time monitoring (i.e., scanning frame tilt fluoroscopy) for transthoracic wall needle aspiration biopsy of small subcostal intrapulmonary nodules, the diagnostic accuracy of which can reach more than 95% .