Value of modern imaging technology in the diaghosis of acute diffuse peritonitis LI Ming-hua，ZHAO Jun-gong. Department of Radiology, the Sixth People’s Hospital of Shanghai Jiao Tong University, Shanghai 200233，China Corresponding author：LI Ming-hua，E-mail：liminghua@online.sh.cn Abstract The imaging diagnosis of spontaneous acute diffuse peritonitis (including peritoneal thickness, fuzzy, effusion) plays the role of prompt diagnosis. Peritoneal changes as well as direct findings of original lesions obtained on contrast enhanced CT are manifestations for the diagnosis of secondary acute diffuse peritonitis, which are important to decide the treatment protocol. CT is a more valuable method than the X-ray film in the diagnosis of acute diffuse peritonitis.