In their prospective evaluation of noncontrast, rapid acquisition half-Fourier acquisition single-shot turbo spin-echo MRI in patients presenting with acute abdominal pain, Byott and Harris [36] demonstrated an overall accuracy of 99% (463 of 468 patients), including detection of diverticular and renal abscesses. The accuracy of MRI in detecting anastomotic leaks has not been studied. FDG-PET/CT Skull Base to Mid-Thigh There are limited recent studies evaluating the use of nuclear medicine imaging in the setting of nonlocalized abdominal pain and fever in the postoperative patient. FDG-PET/CT is useful in the workup of nonlocalized fevers of unknown origin, but in the setting of recent abdominal or pelvic surgery, normal postoperative inflammation could lead to false-positive results. As such, FDG-PET/CT could be used in a complementary fashion to other imaging studies when correlated with relevant surgical and clinical information and when other imaging studies are negative or inconclusive [42]. Nuclear Medicine Older studies performed in the 1980s to 1990s suggested gallium scans and indium and technetium leukocyte scans are useful in evaluating abdominal infections and abscesses when the CT scan is negative or equivocal [43- 45]. However, it is important to recognize that CT technology has significantly advanced since these studies were published. Older literature on technetium-labeled leukocytes also suggested a very high sensitivity and specificity for abdominal abscesses as well, although there are no adequate recent comparisons with CT [46]. In the setting of recent hepatobiliary surgery and specific concern for biliary ductal injury, cholescintigraphy can confirm the presence of a bile leak. Variant 3: Acute nonlocalized abdominal pain. Neutropenic patient. Initial imaging. In neutropenic patients, abdominal pain remains a diagnostic challenge because of the lack of classic clinical and laboratory signs of intra-abdominal disease [8].
Acute Nonlocalized Abdominal Pain. In their prospective evaluation of noncontrast, rapid acquisition half-Fourier acquisition single-shot turbo spin-echo MRI in patients presenting with acute abdominal pain, Byott and Harris [36] demonstrated an overall accuracy of 99% (463 of 468 patients), including detection of diverticular and renal abscesses. The accuracy of MRI in detecting anastomotic leaks has not been studied. FDG-PET/CT Skull Base to Mid-Thigh There are limited recent studies evaluating the use of nuclear medicine imaging in the setting of nonlocalized abdominal pain and fever in the postoperative patient. FDG-PET/CT is useful in the workup of nonlocalized fevers of unknown origin, but in the setting of recent abdominal or pelvic surgery, normal postoperative inflammation could lead to false-positive results. As such, FDG-PET/CT could be used in a complementary fashion to other imaging studies when correlated with relevant surgical and clinical information and when other imaging studies are negative or inconclusive [42]. Nuclear Medicine Older studies performed in the 1980s to 1990s suggested gallium scans and indium and technetium leukocyte scans are useful in evaluating abdominal infections and abscesses when the CT scan is negative or equivocal [43- 45]. However, it is important to recognize that CT technology has significantly advanced since these studies were published. Older literature on technetium-labeled leukocytes also suggested a very high sensitivity and specificity for abdominal abscesses as well, although there are no adequate recent comparisons with CT [46]. In the setting of recent hepatobiliary surgery and specific concern for biliary ductal injury, cholescintigraphy can confirm the presence of a bile leak. Variant 3: Acute nonlocalized abdominal pain. Neutropenic patient. Initial imaging. In neutropenic patients, abdominal pain remains a diagnostic challenge because of the lack of classic clinical and laboratory signs of intra-abdominal disease [8].