Contrast-enhanced ultrasonography of peripheral soft-tissue tumors: Feasibility study and preliminary results.

OBJECTIVES: To determine the diagnostic value of contrast-enhanced ultrasonography, to differentiate benign and malignant soft-tissue tumors and to assess the feasibility and interest of modelling enhancement curves.

PATIENTS AND METHODS: This retrospective study includes 118 patients with soft-tissue tumors, examined with ultrasound after injection of SonoVue(®), a contrast product. The raw data were treated with CHI-Q acquisition software to model the enhancement curves. We analyzed tumor uptake of the contrast product visually and studied the enhancement curves, characterized by five parameters: peak intensity, time to peak, mean transit time, initial slope, and area under the curve.

RESULTS: There were 81 benign and 37 malignant tumors. For a diagnosis of benign tumor, the absence of contrast uptake had a sensitivity of 60%, a specificity of 68%, a positive predictive value of 50% and a negative predictive of 83%. Study of the 70 curves obtained (48 benign and 22 malignant tumors) showed that the parameters of area under the curve (Chi(2)=8.6 and P<0.005), slope (Chi(2)=8.12 and P=0.004), and peak intensity (Chi(2)=7.55, P=0.005) differed significantly between the two populations.

CONCLUSION: Absence of contrast uptake suggests a benign lesion. The study of enhancement curves showed significant differences between the different tumor populations.