 Associated fever with abdominal pain constitutes an even more challenging clinical situation. Fever raises clinical suspicion of an intra-abdominal infection, abscess, or other condition that may need immediate surgical or medical attention. When fever is present, the need for quick, definitive diagnosis is considerably heightened. Imaging is especially helpful in the elderly with acute abdominal pain and fever. In this population, many laboratory tests are nonspecific and may be normal despite serious infection [4-6]. The neutropenic patient is a diagnostic challenge as typical signs of abdominal sepsis may be masked, diagnosis may be delayed [7], and it is associated with a high mortality rate [8]. It is important to note that this overview of imaging focuses on the evaluation of patients with nonspecific abdominal pain, with or without fever, abdominal pain in the setting of recent surgery, and immunocompromised patients with acute abdominal pain. In addition, unless otherwise stated, the ratings and recommendations for this document specifically relate to the adult nonpregnant patient, although the narrative briefly discusses some imaging approaches for younger and pregnant patients in Variant 4. Refer to other Appropriateness Criteria topics aLahey Hospital and Medical Center, Burlington, Massachusetts. bMallinckrodt Institute of Radiology, Saint Louis, Missouri. cResearch Author, Lahey Hospital and Medical Center, Burlington, Massachusetts. dPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. eGeorgetown University Hospital, Washington, District of Columbia; American College of Surgeons. fThe University of South Florida Morsani College of Medicine, Tampa, Florida. gUniversity of Texas McGovern Medical School, Houston, Texas; American Gastroenterological Association. hNewton-Wellesley Hospital, Newton, Massachusetts. iVirginia Tech Carilion School of Medicine, Roanoke, Virginia. jMassachusetts General Hospital, Boston, Massachusetts.
Acute Nonlocalized Abdominal Pain.  Associated fever with abdominal pain constitutes an even more challenging clinical situation. Fever raises clinical suspicion of an intra-abdominal infection, abscess, or other condition that may need immediate surgical or medical attention. When fever is present, the need for quick, definitive diagnosis is considerably heightened. Imaging is especially helpful in the elderly with acute abdominal pain and fever. In this population, many laboratory tests are nonspecific and may be normal despite serious infection [4-6]. The neutropenic patient is a diagnostic challenge as typical signs of abdominal sepsis may be masked, diagnosis may be delayed [7], and it is associated with a high mortality rate [8]. It is important to note that this overview of imaging focuses on the evaluation of patients with nonspecific abdominal pain, with or without fever, abdominal pain in the setting of recent surgery, and immunocompromised patients with acute abdominal pain. In addition, unless otherwise stated, the ratings and recommendations for this document specifically relate to the adult nonpregnant patient, although the narrative briefly discusses some imaging approaches for younger and pregnant patients in Variant 4. Refer to other Appropriateness Criteria topics aLahey Hospital and Medical Center, Burlington, Massachusetts. bMallinckrodt Institute of Radiology, Saint Louis, Missouri. cResearch Author, Lahey Hospital and Medical Center, Burlington, Massachusetts. dPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. eGeorgetown University Hospital, Washington, District of Columbia; American College of Surgeons. fThe University of South Florida Morsani College of Medicine, Tampa, Florida. gUniversity of Texas McGovern Medical School, Houston, Texas; American Gastroenterological Association. hNewton-Wellesley Hospital, Newton, Massachusetts. iVirginia Tech Carilion School of Medicine, Roanoke, Virginia. jMassachusetts General Hospital, Boston, Massachusetts.