In the diagnosis of various medical conditions, it is often useful to examine soft tissues and/or blood flow within the body to show structural details of organs and blood vessels in these organs. Multiple studies have demonstrated increased vascularity (blood flow) in many tumors relative to that of normal tissue, and multiple attempts have been made to depict these differences in vascularity using ultrasonic imaging.
University of Michigan researchers have developed a method for quantitatively estimating the amount of tissue that contains moving blood using power Doppler ultrasound. A region of interest is identified from a frozen image (i.e., a snapshot screen display created by displaying the last real-time image for a given scan), and specified with a pointing device (e.g., a mouse). An object that contains one hundred percent blood flow and is located at the same depth as the region of interest, but not necessarily inside the region of interest, is identified and the corresponding power noted and designated as the reference power level. The display is adjusted to show the one hundred percent blood flow vessel in a designated color and all other power levels are normalized to the reference power level. The fractional blood volume is quantitatively estimated by summing the normalized Doppler power levels and dividing the sum by the number of pixels, all within a region of interest. The numerical result for the specified region of interest may be shown on the display of the ultrasound scanner.
Applications and Advantages
- Medical imaging using ultrasound
- May be implemented by programming a suitable ultrasound machine with an appropriate processor or processors