Approximate quantification of detected fractional blood volume and perfusion from 3-D color flow and Doppler power signal imaging

Abstract

Ultrasound systems have been quite limited in the degree to which they facilitate quantification of reasonably available detected mean tumor flow characteristics such as: detected fractional blood volume, B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</sub> ; speed-weighted, detected fractional blood volume, B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">vv </sub> and mean speed of regionally-detected blood flow, v¯. This lack of quantification follows from the relative disinterest in such quantitative imaging as well as the dependence of any backscattered signal levels on intervening tissues and physical barriers to discrimination of the very slow flow and weak scattering amplitude of the dominant (capillary) blood pool relative to the soft tissue motion and scattering level, respectively. However, new signal power imaging modes offer some of the necessary data for measures such as B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</sub> . Some color flow imaging systems also now offer improved clutter cancellers, sharper high pass filters, and other flexibility in adjustments for low speed flow. In addition, intravenous contrast agents will soon become available. Doing the best that is reasonably possible to quantify observed flow characteristics should aid objective assessment of the potential role of color flow and power mode ultrasound in utilizing the high metabolic rate of most breast cancers and metastases. Examples on a benign breast mass are presented