Abstract：Objective: To study the CT features of extra-pancreatic phlegmon in acute pancreatitis(AP) and the anatomic-pathological bases of its distribution. Materials and Methods: The CT findings of 126 cases of AP proved by operation or clinical treatment were retrospectively analyzed. The CT features of the phlegmon out side of the organ and the anatomic-pathological bases of its distribution were studied. Results: The CT findings of phlegmon appeared irregular soft tissue mass with CT value within 5~30HU, the marginal zone of the phlegmon appeared low-grade enhancement on enhanced scan. The distribution of phlegmon in 259 lesions more commonly appeared in lesser omental bursa(93 times), left anterior pararenal-space(69 times), right paracolonic groove(26 times) and left paracolonic groove(21 times), others including right anterior pararenal-space(12 times), pelvic cavity(11 times), posterior pararenal space, perirenal space and left suprahepatic space(5 times) respectively, left subhepatic space(4 times), right suprahepatic space, left mesentery sinus and thorax(2 times) respectively, right mesentery sinus and pericardiac 1 time respectively. Multiple lesions appeared in 67 cases. Conclusions: The CT findings of phlegmon out of the organ in AP were characteristic. The distribution of the phlegmon depended on the anatomic bases of the abdomen, but some compartment may be involved due to movement of the fluid and the devastating of the phlegmon.
2009, Vol. 20 
