PAI-CHI LIO'donnell, M.M.O'donnell2020-04-162020-04-16199401617346https://scholars.lib.ntu.edu.tw/handle/123456789/484623https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028246343&doi=10.1177%2f016173469401600101&partnerID=40&md5=e952b91055ee045097fc0bdadbfc20f0The inability of diagnostic ultrasound to detect low contrast lesions deep inside the body has limited its success in cancer diagnosis. To enhance low contrast detectability, two-dimensional, very large arrays (VLA's) providing greatly improved spatial resolution have been proposed. Due to discontinuous acoustic windows into the body, however, a significant fraction of such an array might be blocked resulting in degraded detectability in clinical situations. To compensate for this degradation, an object dependent method utilizing multiple receive beams has been proposed and shown to effectively reduce un-desired beamforming artifacts. To further explore the method's capabilities, simulations have been done quantifying improvements in contrast resolution. Using the contrast-to-noise ratio (CNR) as a performance measure, results show that low contrast detectability is determined by sidelobe energy in the point spread function if the total aperture size is not reduced. Moreover, contrast resolution can be restored using the object dependent method if the number of blocked elements is not very significant. If the number of blocked elements is large, however, the method breaks down and performance improvements are minimal. © 1994, SAGE Publications. All rights reserved.Blocked element compensation; contrast resolution; detectability; multiple receive beamforming; very large arrayOptical transfer function; Clinical situations; Contrast resolution; Contrast to noise ratio; Diagnostic ultrasound; Low contrast lesions; Performance measure; Spatial resolution; Very large arrays; Ultrasonic applications; article; cancer diagnosis; diagnostic accuracy; echography; image enhancement; image processing; image quality; signal noise ratiojournal article10.1177/01617346940160010180915492-s2.0-0028246343