Color flow imaging.

The most recent technology change in diagnostic ultrasound is color flow imaging (CFI), which is a merging of gray-scale and motion-detection processing to produce an image that depicts soft tissue in gray scale and blood flow in color. Currently, CFI comes in three forms: synchronous signal processing, asynchronous signal processing, and time domain analysis. The first two employ Doppler-based principles, and the third uses direct measurements of blood flow displacement in the image. All three forms of CFI break the image into multiple sampling segments and process amplitude and motion information. A functional understanding of these technologies helps define and extend their roles in radiology as imaging tools.