Sensitivity of color Doppler sonography: An experimental approach

The purpose of this study was to estimate the size required for small vesse ls to become detectable with color Doppler sonography, A murine experimenta l tumor was examined with color Doppler sonography after injection of 1.5 m t of the contrast medium Levovist(R), Histologically, we measured vessel di ameters inside the tumor, as well as in its direct neighborhood, With color Doppler at a transmit frequency of 7 MHz, vessels were only detected in th e tumor's environment, but not inside. By histology, the 95% quantile of th e vessel diameter distribution was found to be 21 mu m inside the tumor, 37 mu m in the underlying muscle, and 73 mu m in the directly adjacent connec tive tissue. Vessels in the upper range of the size distribution in the mus cle and connective tissue are probably detectable. Using the 95 % quantile as an estimate, and correcting the values for possible shrinkage, using a f actor of 1.91 reported in the literature, vessels in the 74-134 mu m range may be detected under the given conditions, whereas vessels measuring 38 mu m or less are inaccessible to color Doppler, (C) 1999 World Federation for Ultrasound in Medicine & Biology.