Low dose spiral CT of the lungs refers to the optimization of machine scanning parameters, adjustment of tube current, tube voltage, and pitch to reduce radiation dose. Typically, the radiation dose of a routine chest CT scan is about ten millisieverts, which is ten to one hundred times that of a plain film examination. The radiation dose of low-dose chest scan is only one-third of that of routine CT, greatly reducing the radiation dose to the subject. Low dose spiral CT uses the smallest scanning range, lowest dose, and least X-ray volume to diagnose lesions. Compared with traditional conventional CT scans, one is that the dose is small, which reduces the patient's exposure to radiation. Performing low-dose spiral CT on the chest has the same image quality as conventional CT in displaying diffuse lung parenchymal diseases, and there is no significant difference between the two in detecting lung nodules; Using low-dose spiral CT for lung scanning can meet diagnostic requirements and reduce radiation dose, which is excellent for patients.
1、 Advantages of low-dose spiral CT in lung cancer screening. The vast majority of early-stage lung cancer patients have no symptoms, and those who seek medical attention after experiencing symptoms are mostly in the late stage. Advanced lung cancer can be detected by chest X-ray, but early lung cancer presenting as ground glass nodules will be missed by chest X-ray screening. Early lung cancer presenting as soft tissue nodules may also be missed by chest X-ray examination due to their small size. The sensitivity of low-dose CT in detecting early lung cancer is 4-10 times that of conventional chest X-rays, and it can detect early peripheral lung cancer. It can detect small tumors with a diameter of less than 1cm and plays a much greater role in early lung cancer screening.
2、 The role of low-dose spiral CT examination in the lungs
With the increasing awareness of health, physical examination is receiving more and more attention. Low dose lung CT is widely used for early detection of small lesions in the lungs, providing opportunities for further diagnosis and treatment. Its superiority is far greater than chest X-rays. Low dose lung CT is prohibited for pregnant women and has little impact on adults, children, and the elderly. Due to the short examination time and low radiation dose, a scan time of 0.14 seconds will not cause significant harm to the human body, so there is no need to be too nervous. Low dose pulmonary CT is widely used for the diagnosis of difficult respiratory diseases, early detection of ground glass nodules, partial solid nodules, and space occupying solid nodules in the lungs, especially for distinguishing pneumonia, lung cancer, lung abscess, and tuberculosis. It is a very good detection method.
3、 The scope of low-dose spiral CT examination for the lungs
Low dose spiral CT for the lungs refers to a CT examination technique based on the lowest scanning range that can detect small nodules in the lungs, as well as radiation concentration. Due to the significantly higher detection rate of pulmonary nodules by low-dose spiral CT examination compared to chest X-ray examination, and the higher detection rate of pulmonary nodules with a diameter less than 5mm, low-dose spiral CT examination of the lungs can even detect small nodules of 2-3mm. Due to the significantly lower scanning radiation dose of low-dose spiral CT in the lungs compared to regular CT, and the significantly higher sensitivity and specificity than chest X-rays, it is mainly used in screening high-risk populations for lung cancer in clinical practice. It can detect the disease early, improve the early diagnosis rate of lung cancer, and improve the prognosis of patients, and has wide application value in clinical promotion. The high-risk population for lung cancer refers to patients with a long history of smoking or secondhand smoke, chronic lung diseases such as chronic pneumonia, chronic bronchitis, tuberculosis, and long-term exposure to smoke or oil fumes. It is recommended that the above population regularly visit the respiratory department of the hospital for low-dose spiral CT screening of the lungs for about six months, which has the benefits of early detection and treatment. If lung cancer is detected in the population, there is no need to panic excessively. There is still a chance for surgery in the early stage, and the lesion can be surgically removed according to the doctor's advice. If it is in the middle or late stage, clinical treatment methods such as chemotherapy, radiotherapy, and immunotherapy can also be combined to effectively prolong the patient's survival.
4、 Precautions for low-dose spiral CT
1. Before examination, do not wear metal or zippered clothing, underwear with steel rings, or zippered jackets. If you are wearing such clothes or have metal objects such as necklaces, you need to remove them before inspection to avoid artifacts.
2. Before the examination, it is also necessary to inquire whether you are pregnant or in the preparation stage. If you are already pregnant or in the preparation stage, it is not recommended to undergo this examination.
After completing CT, it is necessary to drink more water, eat more vegetables and fruits, which can promote the excretion of radiation.