Strain elastography (SE) in patients with soft tissue tumours – preliminary results from a National Sarcoma

Strain Elastography (SE) evaluates tissue stiffness by means of mechanical displacement of the tissue. SE is routinely used in many anatomical areas including the musculoskeletal system, but no studies have evaluated SE in soft tissue tumours. We present our preliminary results from a selected patient group. Aim: To evaluate SE in the diagnosis of soft tissue tumours by two semi-quantitative methods strain-ratio (SR) and strain histograms (SH) in patients with tumours suspect of sarcoma. Materials and Methods: Patients with tumours or lesions suspect of sarcoma on MRI, who were scheduled for ultrasound-guided biopsy, were included consecutively. All patients underwent histological biopsy with a fully automatic 18g needle. SE was performed on a GE Logiq E9 system using a linear or curved array transducer and musculoskeletal pre-setting before biopsy. Each examination was recorded and the most representative video (10 sec) was chosen by three observers for further studies and calculation. Results: Fourteen patients (9 female and 5 male) were initially included from January to February 2014. One patient (female) was excluded due to an insufficient biopsy. Mean age of the 13 remaining patients was: 56.5 years (range: 41-71 years). Four patients had malignant diagnoses and 9 had non-malignant diagnoses. Mean SR for malignant tumours: 4.7 (range: 2.2-7.1). Mean SH value: 183 (range: 143-222). Mean SR for benign lesions: 2,6 (range: 0.2-5.0). Mean SH value: 166 (range: 112-220). Conclusion: SE can be used as an adjunct to B-mode ultrasound and Doppler ultrasound, but there is an overlap in stiffness in benign and malignant tumours. A larger patient group is needed to establish cut-offs for SR and SH.