Doppler ultrasound systems designed for tumor blood flow imaging

There is a great need for adaptable instrumentation for imaging the volume and dynamics of flowing blood in cancerous lesions. Applications include basic biological research and clinical diagnosis. Commercial instruments are not currently optimized for such applications and system modification for research is difficult if at all possible. This paper describes a laboratory instrument for developing tumor imaging techniques. It compares common and improved estimators through a detailed error analysis of simulated and experimental echo data. Broadband power-Doppler imaging with contrast media is found to be ideal for visualizing the volume of moving blood. The two-dimensional autocorrelator in color-flow imaging for time-resolved velocity estimation provides unbiased estimates and is reasonably efficient for broadband echoes. Ultrasonic blood flow imaging can be sensitive for tumor imaging if the instrumentation and algorithms are optimized specifically for the experimental conditions.