New hemodynamic approach to angiogenesis - Color and pulsed Doppler ultrasonography

RATIONALE AND OBJECTIVES. To determine the capacity of color and spectral D oppler ultrasonography (US) to quantify angiogenesis in vivo and to charact erize low-resistance intratumor blood how. METHODS. Thirty-two tumors, xenografted into mice, were studied with Dopple r US. The number of intratumor vessels visualized with color Doppler US was compared with the density of microvessels and the number of vessels >100 m u m determined by histologic examination. The resistance index and the peak systolic velocities were evaluated. RESULTS. The number of intratumor vessels visualized by color Doppler US wa s correlated with the number of vessels >100 mu m (P < 0.001) determined hi stologically. When vessel density was >30, intratumor vessels were always d etected by color Dopper US, The resistance indew and peak systolic velociti es were significantly lower in intratumor than in peritumor vessels. CONCLUSIONS. Color Doppler US evaluated tumor angiogenesis accurately. Spec tral analysis confirmed the low resistance of intratumor blood flow.