Examining moving objects by ultrasound echograpy

An apparatus for scanning moving objects, notably flowing blood, by means of ultrasound echography in order to determine movement parameters of such objects. The apparatus comprises at least one ultrasound transducer which is connected to a stage for the periodic transmission of a pulse signal having a predetermined recurrent frequency F=1/T and to a stage for receiving echograpic signals returned to the transducer and for processing the signals received. In accordance with the invention, the apparatus is characterized in that it comprises a digital processing channel which is successively composed of a circit (320) for suppressing fixed echoes, a circuit for estimating flow parameters, a discriminator circuit (360), a device (370) for storage, scan conversion and color encoding, and a display device (312).