Fig. 2

Missed diagnosis and misdiagnosis cases of CT sonography. a Case 1 (sinus confined to the abdominal wall), a 56-year-old male, CT shows that the abscess cavity protrudes into the abdominal cavity (arrow). b, c Case 2 (sinus tract confined to the abdominal wall), a 65-year-old male, the sinus runs in a strip antero-posteriorly (arrow), and a mass formed by fat necrosis (☆) can be seen in the adjacent abdominal wall. The adjacent peritoneum appears intact (curved arrow). d Case 5 (sinus involving the abdominal cavity), a 66-year-old man, the sinus is mainly located in the abdominal wall on CT image (arrow). The adjacent peritoneum is thickened, but its integrity could not be judged. e Case 6 (sinus involving the abdominal cavity), a 71-year-old man, the sinus involves the abdominal cavity, with deep abscess (arrow) containing many small bubbles (curved arrow), leading to misdiagnosis of ECF. f Case 7 (ECF), an 82-year-old female. Most of the lesion is in the abdominal wall (arrow) and closely adhered to the adjacent intestinal wall. There are no signs of ECF. g, h Case 8 (ECF), a 64-year-old male, the sinus involves the abdominal cavity, and the adjacent mesh is thickened and curled (curved arrow). No signs of ECF are found. i Case 4 (sinus confined to the abdominal wall), a 32-year-old female, the abdominal wall around the sinus is obviously thickened (curved arrow), and the border with the anterior bladder wall is indistinct (arrow). The bladder density increases up to 76HU due to entry of the contrast agent (☆), which lead to a misdiagnosis of vesico-cutaneous fistula. CT computed tomography, ECF enterocutaneous fistula