A smaller retrospective study evaluating the performance of US in patients who had initially undergone multidetector CT interpreted by experienced readers showed that CT was 100% sensitive in the detection of tubo-ovarian abscesses (n = 9), and performing a follow-up US did not aid in diagnosis [40]. Although not specifically performed to evaluate for abscesses, a large prospective study evaluating the usefulness of CT and US in patients presenting with abdominal pain (n = 1,021) showed better sensitivity with CT in diagnosis of appendicitis (94% versus 76%, P < . 01) and diverticulitis (81% versus 61%, P = . 048) [41]. US and CT had similar sensitivities for the detection of acute cholecystitis. FDG-PET/CT Skull Base to Mid-Thigh Although generally not the primary modality of choice in the setting of acute or emergent abdominal pain, nuclear medicine studies could be used as an adjunct to inconclusive cross-sectional imaging. Because of its whole body imaging and sensitivity for infectious, inflammatory, and neoplastic processes, PET using the tracer fluorine-18- 2-fluoro-2-deoxy-D-glucose (FDG)/CT is useful in the setting of nonlocalized fevers of unknown origin, particularly if previous cross-sectional imaging did not yielded a source [42]. Nevertheless, there are no recent studies evaluating its use when patients present with symptoms localizing to the abdomen. Variant 2: Acute nonlocalized abdominal pain and fever. Postoperative patient. Initial imaging. In the setting of recent abdominal surgery, a variety of conditions could produce abdominal pain, including postoperative fluid collections, hemorrhage, vascular injuries, intestinal ileus, omental torsion/infarction, etc. However, the presence of concomitant fever is primarily concerning for a postoperative abscess and warrants cross-sectional imaging for further evaluation. In addition, patients who have had recent bowel manipulation or Acute Nonlocalized Abdominal Pain
Acute Nonlocalized Abdominal Pain. A smaller retrospective study evaluating the performance of US in patients who had initially undergone multidetector CT interpreted by experienced readers showed that CT was 100% sensitive in the detection of tubo-ovarian abscesses (n = 9), and performing a follow-up US did not aid in diagnosis [40]. Although not specifically performed to evaluate for abscesses, a large prospective study evaluating the usefulness of CT and US in patients presenting with abdominal pain (n = 1,021) showed better sensitivity with CT in diagnosis of appendicitis (94% versus 76%, P < . 01) and diverticulitis (81% versus 61%, P = . 048) [41]. US and CT had similar sensitivities for the detection of acute cholecystitis. FDG-PET/CT Skull Base to Mid-Thigh Although generally not the primary modality of choice in the setting of acute or emergent abdominal pain, nuclear medicine studies could be used as an adjunct to inconclusive cross-sectional imaging. Because of its whole body imaging and sensitivity for infectious, inflammatory, and neoplastic processes, PET using the tracer fluorine-18- 2-fluoro-2-deoxy-D-glucose (FDG)/CT is useful in the setting of nonlocalized fevers of unknown origin, particularly if previous cross-sectional imaging did not yielded a source [42]. Nevertheless, there are no recent studies evaluating its use when patients present with symptoms localizing to the abdomen. Variant 2: Acute nonlocalized abdominal pain and fever. Postoperative patient. Initial imaging. In the setting of recent abdominal surgery, a variety of conditions could produce abdominal pain, including postoperative fluid collections, hemorrhage, vascular injuries, intestinal ileus, omental torsion/infarction, etc. However, the presence of concomitant fever is primarily concerning for a postoperative abscess and warrants cross-sectional imaging for further evaluation. In addition, patients who have had recent bowel manipulation or Acute Nonlocalized Abdominal Pain