X-ray or gamma ray systems or devices – Miscellaneous
Patent
1995-03-24
1996-08-27
Porta, David P.
X-ray or gamma ray systems or devices
Miscellaneous
378901, G06F 1566
Patent
active
055508928
ABSTRACT:
Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.
REFERENCES:
patent: 4189775 (1980-02-01), Inouye
patent: 4365339 (1982-12-01), Pavkovich
patent: 4433380 (1984-02-01), Abele et al.
patent: 4446521 (1984-05-01), Inouye
patent: 4670892 (1987-06-01), Abele et al.
patent: 5319551 (1994-06-01), Sekiguchi et al.
A. M. Cormack, "Representation of a Function by Its Line Integrals, With Some Radiological Applications," 9 Journal of applied Physics, vol. 34, pp. 2722-2727 (Sep. 1963).
R. H. Huesman, "A New Fast Algorithm for the Evaluation of Regions of Interest and Statistical Uncertainty in computed Tomography," 5 Phys. Med. Biol., vol. 29, pp. 543-552 (1984).
Adel Faridani et al., "Local Tomography," 2 Siam J. Appl. Math., vol. 52, pp. 459-484 (Apr. 1992).
Katsevich Alexander J.
Ramm Alexander G.
Porta David P.
The Regents of the University of California
Wilson Ray G.
LandOfFree
Enhanced local tomography does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Enhanced local tomography, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enhanced local tomography will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1062003