Missing array elements due to discontinuous acoustic windows into the body produce undesired beamforming artifacts and degrade spatial and contrast resolution. To minimize undesired artifacts, an algorithm using multiple receive beams and the totalleast-squares (TLS) method is proposed in this paper. Results show that this algorithm can effectively reduce imperfections in the point spread function of the imager. Combined with local scatterer statistics, the algorithm is modified for compensation on distributed scattering sources. Results also indicate that compensated images are comparable to full array images. This method, therefore, can enhance detection of low contrast lesions using large phased array apertures.
|Original language||English (US)|
|Title of host publication||1992 Ultrasonics Symposium Proceedings|
|Publisher||Institute of Electrical and Electronics Engineers Inc.|
|Number of pages||4|
|State||Published - 1992|
|Event||1992 Ultrasonics Symposium - Tucson, United States|
Duration: Oct 20 1992 → Oct 23 1992
|Name||Proceedings - IEEE Ultrasonics Symposium|
|Conference||1992 Ultrasonics Symposium|
|Period||10/20/92 → 10/23/92|
Bibliographical noteFunding Information:
dows into the body, a set of phased array elements may be inactive in clinical applications. In particular, if a very large aperture (VLA) is used, the number of missing (i.e., inactive) array elements due to gas and bone may be a substantial fraction of the total array. These missing elements are likely to produce severe artifacts depending on their number and position [l]. In general. higher sidelobe levels are observed in the corrupted beam pattern. Additionally, if missing elements are located at the edge of the array, i.e., if the total aperture size is reduced, a wider mainlobe results. One possible solution is the direct beam synthesis technique developed for hyperthermia arrays . In this approach, a set of control points are chosen as a subset of the desired beam pattern. By formulating a linear propagation relation between the control points and complex array weights, the optimal aperture function (i.e., complex weights) can be obtained by multiplying the pseudoinverse 'This work is supported by the National Institutes of Health under Grant CA 54896 and the General Electric Company.
© 1992 IEEE.