Differentiation of malignant and benign musculoskeletal tumors: combined color and power Doppler US and spectral wave analysis.

PURPOSE

To assess the use of combined color Doppler ultrasonography (US), power Doppler US, and spectral wave analysis (SWA) in differentiating malignant and benign musculoskeletal tumors.

MATERIALS AND METHODS

Seventy-nine musculoskeletal tumors (34 malignant, 45 benign) were examined with color and power Doppler US and SWA. Two radiologists independently assessed US images and SWA findings. Echotexture and vessel characteristics such as stenoses, occlusions, loops, shunts, trifurcations, vascular pattern, and resistive index were evaluated. All tumors were subject to US-guided or open biopsy for histologic correlation.

RESULTS

Combined color and power Doppler US and SWA revealed four major (stenosis, occlusion, trifurcation, vascular pattern) and three minor (shunt, self loop, resistive index) vessel characteristics, which proved helpful in differentiating benign from malignant lesions. Echotexture showed moderate sensitivity (82% [28 of 34 tumors]) and low specificity (38% [17 of 45 tumors]). When comparing several combinations of vessel characteristics, a combination of any two major characteristics demonstrated the best results (sensitivity, 94% [33 of 39 tumors]; specificity, 93% [three of 45 tumors]). Combining more than two characteristics resulted in lower sensitivity.

CONCLUSION

Combined color and power Doppler US and SWA may enable assessment of vascular architecture and altered flow of musculoskeletal tumors. Vascular architecture analysis enables differentiation of benign and malignant lesions and evaluation of musculoskeletal tumors.