Zobrazeno 1 - 10
of 69
pro vyhledávání: '"K.W. Rigby"'
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 45:691-703
Previous studies have shown that the parallel adaptive receive compensation algorithm (PARCA) can improve clinical images of the abdomen degraded by aberrations. Corrected images show both improved contrast resolution and overall image quality. Howev
Autor:
Kai Erik Thomenius, K.W. Rigby, C.M.W. Daft, Douglas Glenn Wildes, Lowell Scott Smith, R.Y. Chiao
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 44:1027-1037
Present 1D phased array probes have outstanding lateral and axial resolution, but their elevation performance is determined by a fixed aperture focused at a fixed range. Multi-row array transducers can provide significantly improved elevation perform
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 44:701-713
Two previous approaches to estimate phase aberration profiles with a single transmit pulse from speckle are examined. The first employs cross-correlation between signals on all pairs of neighboring elements. In the other, cross-correlation between si
Publikováno v:
IEEE Ultrasonics Symposium, 2004.
Angular scatter imaging has been proposed as a new source of image contrast in medical ultrasound and as a parameter for tissue characterization. We describe a new method that combines the translating apertures algorithm (TAA) with synthetic aperture
Publikováno v:
Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004..
Conventional coherent imaging systems map the energy which is reflected directly back towards the transducer. While extremely useful, these systems fail to utilize information in the energy field which has been scattered at other angles. Angular scat
Publikováno v:
1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027).
The coherence factor provides a quantitative measure of image quality. It is defined as the ratio of the coherent sum across array elements to the incoherent sum and measures the distribution of ultrasonic energy between the main beam and side lobes
Publikováno v:
1996 IEEE Ultrasonics Symposium. Proceedings.
The Parallel Adaptive Receive Compensation Algorithm (PARCA) uses multiple receive beams to compensate for imperfect beam forming. Previous studies demonstrated that PARCA can correct for controlled aberrations in tissue equivalent phantoms. Here, we
Publikováno v:
1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).
1.5D arrays have been proposed to improve elevational beam focus over 1D arrays (D.G. Wildes et al., 1997). The design of 1.5D arrays is complicated by the potential for large elevational row dimensions which results in many possible design tradeoffs
Autor:
K.M. Durocher, D.P. Miller, G.A. Lillegard, Douglas Glenn Wildes, J.K. Sleeter, J.J. David, W.A. Hennessy, Lowell Scott Smith, A.A. Bhave, J.J. Strother, G.L. Potrykus, Venkat Subramaniam Venkataramani, Robert S. Lewandowski, L.J. Keres, N.H. Tea, G.C. Sogoian, K.W. Rigby, X.M. Lu
Publikováno v:
1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).
Commercial arrays for medical imaging do not adequately sample the spatial variation of the speed of sound in human abdominal wall tissue. These arrays sense only the average properties of a region of tissue and are unable to achieve significant corr
Autor:
S.M. Peshman, M.G. Angle, Carl L. Chalek, W.M. Leue, W.L. Hinrichs, Lewis J. Thomas, Steven C. Miller, R.A. Hogel, M.A. Peters, B.T. McEathron, K.W. Rigby, B.H. Haider, Matthew O'Donnell, S. Krishnan, E.A. Andarawis
Publikováno v:
1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).
Sound speed variations within the human body degrade contrast and resolution in ultrasound images. Many algorithms have been proposed to compensate for these variations, but few have been tested on human subjects. We describe a programmable, adaptive