Evaluation of soft-tissue masses using segmented color Doppler velocity images: Preliminary observations

OBJECTIVE. We report our initial experience with segmented color Doppler ve locity-based estimates of tumor vascularity for various histogically proven soft-tissue masses. SUBJECTS AND METHODS. Color Doppler sonography of 23 histologically proven masses in 22 patients was performed. Digital color Doppler images were acqu ired directly off the scanner output or from video recordings and stored on a personal computer as 24-bit gray-scale and color composite images. A col or Doppler velocity segmentation and analysis algorithm was applied to the digital images, from which we calculated the normalized percentage of color Doppler area. Normalization was determined by expressing color Doppler are a as a percentage of the area enclosed by a preselected region of interest. We also calculated mean percentage, SD, and cumulative distribution of col or Doppler area, relative to a fixed threshold, for the acquired image data sets. RESULTS. Estimates of mean percentage of color Doppler area showed a dynami c range of at least two or three orders of magnitude between lowest and hig hest values obtained. A scatterplot of mean percentage of color Doppler are a versus SD of percentage of color Doppler area showed a linear monotonic r elationship (r(2) =.92), illustrating increasing vascular heterogeneity wit h mean vascularity. Preliminary data also suggest the presence of at least two distinct groups of masses (p <.0001) based on these vascularity estimat es, One group corresponds to high-grade lesions in which tumor angiogenesis is expected to be important in predicting biologic behavior The second gro up appeared to have little or no relationship to tumor vascularity or was o f an intermediate (or lower) histologic grade. CONCLUSION. Quantitative color Doppler estimates of tumor vascularity can b e obtained over a wide dynamic range, Such estimates provide a mechanism to assess vascular heterogeneity of soft-tissue tumors, Preliminary data sugg est that two biologically distinct groups of masses may be separable on the basis of quantitative velocity-based estimates of tumor vascularity as obt ained from color Doppler sonography.