Pelvic Inflammatory Disease Diagnosis and Imaging

CT Findings and Diagnostic Approach

Fat stranding represents abnormally increased attenuation in fat tissue associated with regional free fluid or edema, indicating inflammatory changes, and is highly sensitive for detecting underlying pathology, serving as a clue to identify the source of inflammation, according to the American College of Radiology 1
Pelvic fluid and peritoneal thickening are demonstrated on CT in chronic pelvic inflammatory disease, and hydrosalpinx or pyosalpinx may be visible, with the American College of Radiology recommending contrast-enhanced CT for evaluating PID 2
IV contrast allows detection of abnormal enhancement of structures and rim-enhancement suggesting abscess formation, and fat stranding is best visualized on contrast-enhanced CT, with non-contrast CT having lower sensitivity for detecting subtle fat stranding, as stated by the American College of Radiology 3

Fat stranding in the pelvis is not specific to PID, and similar patterns occur in diverticulitis, with pericolonic fat stranding, according to the American Academy of Family Physicians 4
Inflammatory bowel disease can also cause perienteric fat stranding, as noted by the American College of Radiology 6