Patent ID: 6485423
Filing Date: 2002-11-26
Classification: A61B,G01S

Abstract:
A method for corrections of phasefront aberrations and pulse reverberations in medical ultrasound imaging, whereultrasound beams on transmit and/or receive are formed with an ultrasound transducer array that has a two-dimensional distribution of elements, a maximal linear dimension of the elements being smaller than a spatial correlation length of the phase amplitude seen across the array surface, a individual array element signals are filtered in a correction filter before standard beam forming is done, both for the transmit and/or the receive beams, the correction filters are estimated byintroducing into a soft tissue image field one or more artificial ultrasound point scatterers, receiving backscatterd signal from the point scatterers with the transducer array, the point scatterers being spaced apart that the signals from the individual scatterers can clearly be discriminated from each other, the signals from the point scatterers having characteristics in amplitude or frequency content, or both, so that they are clearly separable from the tissue signal, the signals from the individual point scatterers being used to derive correction filters to correct for phase aberrations and pulse reverberations both in the receive and the transmit beams.