Epidemiological Data and Clinical Findings: Non-Traumatic Acute Abdomen.- Traumatic acute abdomen.- Key CT Findings: Features and Significance CT Findings.- CT Techniques: Non-Traumatic Acute Abdomen.- Traumatic Acute Abdomen.- CT Diagnosis in Non-Traumatic Abdomen: Acute Liver Disease.- Acute Biliary Disease.- Acute Splenic Disease.- Pancreatitis.- Appendicitis.- Diverticulitis.- Colitis.- Gastritis and Enteritis.- Ischemia (Acute Mesenteric Ischemia and Ischemia Colitis).- Bowel Obstruction.- Bowel Perforation.- GI Bleeding.- Intra and Retroperitoneal Bleeding.- Renal and Adrenal Emergencies.- Gynecological Emergencies.- Acute Disease of the Intra-Abdominal Fat (Panniculitis, Appendagitis, GE Torsion).- Acute Disease of the Muscles and of the Abdominal Wall.- Complications of Surgery (Abdominal, Urologic and Gynecologic Emergencies).- CT Diagnosis in Traumatic Abdomen: Blunt Trauma.- Open Trauma.- Subject Index.