Abstract: A format for ultrasonic image data storage is described that utilizes a standard data formatting system to provide information specific to ultrasonic images and, in particular, sequences of ultrasonic images. The format utilizes a technique of tagged data records with a unique tag that extends the standardized to ultrasonic image specific tages. On tag denotes a particular image in a sequence of images which is marked as the image which is representative of the sequence. Specific areas of an ultrasonic image which contain distinct types of data are tagged to identify the type of data in the area. The distinct types of data can be arranged in unique ranges of data values so that a particular data value will inherently identify the type of data to which the value relates. Blocks of image data comprising monochrome or color data can be tagged as to the data type, enabling luminance data or red, green and blue data to be alternatively represented in the data values and automatically processed accordingly.

Abstract: An ultrasonic diagnostic imaging system is described which enhances the presentation of flow velocity images through asymmetric persistence of visually displayed changes in fluid velocity. Preferably the asymmetric persistence employs a shorter (i.e., faster) time constant for increases in fluid velocity and a longer (i.e., slower) time constant for decreases in fluid velocity. In a preferred embodiment of the present invention, increases in fluid velocity are displayed at their rate of occurrence, and decreases in fluid velocity are displayed with a longer, user-selectable time constant. In the preferred embodiment the persistence enhancement is determined as a function of displayed image frame rate so that the persistence time constant remains fixed as a function of time despite user changes affecting the frame rate.