Objectives: To investigate whether ultrasound elastography (UE) is an effective non-invasive diagnostic procedure for evaluating benign and malignant thickened greater omentum.
Methods: Ultrasound elastographic images from 118 patients who underwent ultrasound-guided biopsy for thickened greater omentum from May 2012 to October 2013 were retrospectively analysed. The results were compared with the pathological findings from the biopsies, and evaluated by ROC curve analysis.
Results: A total of 93.6% of the benign thickened greater omentum had elasticity scoring of 1 or 2, whereas 93.0% of the malignant thickened greater omentum had elasticity scoring of 3 or 4. The elasticity strain ratios for malignant thickened greater omenta were higher than for benign thickened greater omenta using muscle or fat yielded as reference tissue (P < 0.01). The optimal cut-off point for elasticity strain ratios using fat as reference was 2.6. The sensitivity, specificity, accuracy, and positive and negative predictive values for determining elasticity strain ratios using fat as reference were 83.3%, 90.6%, 86.5%, 92.1%, and 80.6%, respectively, and for elasticity scoring were 95.2%, 96.9%, 95.9%, 97.6%, and 93.9%, respectively.
Conclusions: UE using elasticity scoring or elasticity strain ratios is an effective new non-invasive method for differentiating benign from malignant thickened greater omentum.
Key points: • Elasticity score is an objective method for differentiating greater omentum lesions. • Elasticity strain ratio is another method for differentiating greater omentum lesions. • Fat tissue is better than abdominal wall muscle as reference in elasticity imaging. • UE is a new effective, non-invasive method for diagnosing omental diseases.
Keywords: Elastic strain ratio; Elasticity scores; Greater omentum; Ultrasound elastography; Ultrasound-guided biopsy.