19.What is inguinal hernia? The Hernia and Abdominal Wall Surgery Group of the Chinese Society of Medical Surgeons, June 2012, in the Guidelines for the Treatment of Inguinal Hernia in Adults: Inguinal hernia refers to an extra-abdominal hernia that occurs in the inguinal region, i.e., a hernia sac structure exists in the inguinal region that protrudes toward the body surface, and organs or tissues in the abdominal cavity can enter the hernia sac through a congenital or acquired abdominal wall defect. A typical inguinal hernia has structures such as a hernia ring, a hernia sac, a hernia contents and a hernia cover. In layman’s terms, this means that the contents of the stomach have escaped into the belly. 20. By what means is an inguinal hernia diagnosed? Any patient with swelling in the inguinal area, confined area of swelling, or discomfort in the inguinal area may have an inguinal hernia and needs to be examined in depth. A:Inguinal hernia can be diagnosed by physical examination by a physician; it has a sensitivity of 74.5-92% and a specificity of 93%. It means that only 74-92 out of 100 patients with inguinal hernia can be diagnosed by physicians after physical examination; out of 100 patients diagnosed with inguinal hernia by physicians, 93 are finally confirmed to be inguinal hernia. B:Ultrasound is a valuable and noninvasive screening tool. Clinically, 81-100% of patients with inguinal hernia diagnosed by ultrasound have surgically confirmed inguinal hernia (results vary from study to study). Of patients with clinically confirmed inguinal hernia, 33-100% can be detected by ultrasound (results vary between studies). C:CT has a sensitivity of 83% and a specificity of 67-83% for the diagnosis of inguinal hernia, which means that CT can only detect 83% of patients with a definite inguinal hernia; 67-83% of patients with a definite inguinal hernia diagnosed by CT end up with a definite inguinal hernia. CT is of good diagnostic value when inguinal hernia is combined with bladder hernia. D: NMR has the clear advantage that he is a non-invasive test with a sensitivity of 94.5% and a specificity of 96.3%. In other words, 94.5% of patients diagnosed with inguinal hernia were detected by MRI; 96.3% of patients diagnosed with inguinal hernia by MRI were finally diagnosed with inguinal hernia.