Influenza A (H1N1) (earlier known as the new swine flu, Novel swine-origin influenza A (H1N1) virus ,S-OIV) in the spring of 2009 in Mexico and other countries outbreak epidemic and rapid global spread, the World Health Organization (World Health Organization , WHO) in 2009 In June 2009, the World Health Organization (WHO) raised the level of infection alert to level 6. According to the WHO on December 30, 2009 announced the latest epidemic notification, as of December 27, 2009, 208 countries worldwide have reported confirmed cases of influenza A (H1N1), has caused at least 12,220 deaths. China’s Ministry of Health informed on January 2, 2010 that, as of December 31, 2009, the country’s 31 provinces reported a total of more than 120,000 confirmed cases of influenza A, cure 110,000 cases, 648 deaths. Influenza A (H1N1) is caused by a mutation of the new influenza A (H1N1) virus caused by acute respiratory infectious diseases, mainly through droplet transmission through the respiratory tract. Clinical manifestations are mainly flu-like symptoms, most of the symptoms are light, a few can occur pneumonia and other complications. Influenza A (H1N1) combined with pneumonia can lead to aggravation of the disease, early diagnosis can avoid rapid progress due to improper treatment, respiratory failure and multiple organ function damage. Influenza A (H1N1) chest X-ray and CT performance so far has been reported in the literature abroad, but the domestic case report only, in order to strengthen the understanding of the disease imaging performance, the relevant domestic and foreign literature for review, is reviewed below. 1, epidemiology Influenza A (H1N1) infectious source mainly for people or animals carrying the virus, the main route of transmission for respiratory transmission, but also through contact with contaminated objects around the transmission. Incubation period: half a day to 3 days, up to 7 days. The onset of the population is mostly young adults, and seasonal influenza is different, the latter’s susceptible population for the elderly and children. Influenza A (H1N1) originally called human swine flu, in order to avoid the “swine flu” term on the people’s misleading, April 30, 2009, the World Health Organization, the United Nations Food and Agriculture Organization and the World Organization for Animal Health announced that agreed to use the H1N1 type of influenza to refer to the epidemic at the time, and no longer use “H1N1 refers to the surface of the virus glycoprotein, H represents erythrocyte agglutinin, a total of 1-15 types, N represents neuraminidase, a total of 1-9 types, this virus H and N are type 1, so called H1N1. China’s Ministry of Health was renamed influenza A H1N1. 2, clinical performance Influenza A H1N1 typical clinical manifestations of fever, sore throat, cough, chills, headache, runny nose, shortness of breath, myalgia, arthralgia, fatigue, vomiting and diarrhea [7]. 642 patients reported by Dawood et al. aged 3 months-81 years, 60% of young people aged 18 years, the most common clinical symptoms fever (94%), sore throat (66%), cough (92%) The most common clinical symptoms were fever (94%), sore throat (66%), cough (92%), vomiting (25%), and diarrhea (25%). Most patients have mild symptoms, while a very small number have severe symptoms that can lead to respiratory failure or even death. The total white blood cell count is generally not high or reduced in peripheral blood tests, and some cases have hypokalemia in blood biochemical tests. Confirmation criteria: patients with influenza-like clinical manifestations, along with one or more of the following laboratory test results can confirm the diagnosis: 1, positive nucleic acid detection of influenza A (H1N1) virus (can be used real-time RT-PCR and RT-PCR methods); 2, isolated to influenza A (H1N1) virus; 3, double serum influenza A (H1N1) virus-specific antibody levels were 4 or more than 4-fold increase.