CT Abdomen Although it has not been advocated as a primary imaging examination for acute right upper quadrant pain, CT with IV contrast can confirm or refute the diagnosis of AC in equivocal cases based on US or scintigraphy, with a negative predictive value approaching 90% [30]. CT may reveal such complications as gangrene, gas formation, intraluminal hemorrhage, and perforation [15-17,30-35]. Furthermore, CT has been advocated as a useful modality in preoperative planning, with the absence of gallbladder wall enhancement or presence of a stone within the infundibulum associated with conversion from laparoscopic to open cholecystectomy. Prior knowledge of these imaging findings may help guide appropriate surgical approach [46]. Clinical conditions that can mimic AC, in terms of presentation with acute right upper quadrant pain, include chronic cholecystitis, peptic ulcer, pancreatitis, gastroenteritis, ascending cholangitis, and bowel obstruction, among others. However, AC is a fairly common disease that presents with right upper quadrant pain and is often the initial diagnosis to exclude. If US or scintigraphy are negative for AC and there is no alternative diagnosis, CT, preferably with IV contrast, is the next preferred imaging examination for identifying those disorders. When a diagnosis of AC is not prospectively suspected, CT may also be used to demonstrate AC in patients who have nonspecific abdominal pain. The CT findings in AC are similar to those encountered by US [7] with the exception of gallstones, which may not be seen with CT. Other potential findings include adjacent liver parenchymal hyperemia, which cannot be detected without IV contrast. Abnormal gallbladder wall enhancement can be seen in more advanced cases [7]. Right Upper Quadrant Pain
Right Upper Quadrant Pain. CT Abdomen Although it has not been advocated as a primary imaging examination for acute right upper quadrant pain, CT with IV contrast can confirm or refute the diagnosis of AC in equivocal cases based on US or scintigraphy, with a negative predictive value approaching 90% [30]. CT may reveal such complications as gangrene, gas formation, intraluminal hemorrhage, and perforation [15-17,30-35]. Furthermore, CT has been advocated as a useful modality in preoperative planning, with the absence of gallbladder wall enhancement or presence of a stone within the infundibulum associated with conversion from laparoscopic to open cholecystectomy. Prior knowledge of these imaging findings may help guide appropriate surgical approach [46]. Clinical conditions that can mimic AC, in terms of presentation with acute right upper quadrant pain, include chronic cholecystitis, peptic ulcer, pancreatitis, gastroenteritis, ascending cholangitis, and bowel obstruction, among others. However, AC is a fairly common disease that presents with right upper quadrant pain and is often the initial diagnosis to exclude. If US or scintigraphy are negative for AC and there is no alternative diagnosis, CT, preferably with IV contrast, is the next preferred imaging examination for identifying those disorders. When a diagnosis of AC is not prospectively suspected, CT may also be used to demonstrate AC in patients who have nonspecific abdominal pain. The CT findings in AC are similar to those encountered by US [7] with the exception of gallstones, which may not be seen with CT. Other potential findings include adjacent liver parenchymal hyperemia, which cannot be detected without IV contrast. Abnormal gallbladder wall enhancement can be seen in more advanced cases [7]. Right Upper Quadrant Pain