Ultrasound and color power Doppler in the detection of metastatic omentum: a prospective study

Objectives: To analyze prospectively the ability of ultrasound to detect metastatic omentum in patients with suspicious pelvic masses and to describe the sonographic features of metastatic omental disease. Methods: One hundred and eighty-four patients were evaluated preoperatively by ultrasound examination and of these 173 were used in the analysis. We defined as an ultrasound-positive examination one which visualized intra-abdominal aperistaltic solid tissue, located above the bowel loops and below the anterior peritoneal surface. Preoperative sonographic findings were compared with pathological results. Results: Sonographic detection of metastatic omentum was achieved in 104 of 173 patients (60.1%), appearing as either solid aperistaltic tissue (80.8% of cases), or as solid discrete nodules (19.2%). When considering the echostructure of the surrounding bowel loops, this tissue appeared hypoechoic in 46 (44.2%) cases and isoechoic or slightly hyperechoic in the other 58 (55.8%) cases. In the overall series, the negative and positive predictive values (NPV and PPV) and the accuracy of ultrasound examination were 92.7%, 91.3% and 91.9%, respectively. When considering only the group of ovarian tumors, the NPV, PVC and accuracy were 91.9%, 94.6%, and 93.8%, respectively. Conclusion: Ultrasound examination is highly accurate in detecting metastatic omental involvement in cases with suspicious pelvic masses