Radiant energy – Invisible radiant energy responsive electric signalling – Semiconductor system
Reexamination Certificate
1998-10-01
2001-02-27
Hannaher, Constantine (Department: 2878)
Radiant energy
Invisible radiant energy responsive electric signalling
Semiconductor system
C250S363020, C250S363030, C250S366000, C250S369000
Reexamination Certificate
active
06194728
ABSTRACT:
FIELD OF THE INVENTION
The present invention pertains to the field of medical imaging equipment. More particularly, the present invention relates to a system for performing both planar studies as well as single-photon emission and positron emission tomography.
BACKGROUND OF THE INVENTION
There are two distinctive types of imaging systems in contemporary nuclear medicine. One type is represented by the gamma scintillation cameras (GSCs), the so-called “position sensitive” continuous-area detectors, and the other one by Positron Emission Tomography (PET) scanners. The first type deals with the single photon gamma emitters enabling planar static and dynamic studies as well as Single Photon Emission Computed Tomography (SPECT), while the second type enables tomographic imaging of the positron emitters, i.e., PET studies. Both techniques enable direct imaging of biochemical processes “in vivo” (especially, the PET technique) and the study of physiological processes and dysfunctions in a quantitative manner. However, imaging systems for both types of techniques are rather expensive. The costs involved for these systems have greatly contributed to the overall expenditures for contemporary high technology medicine, which is a serious problem even in the most developed countries (e.g., U.S.A., Japan, United Kingdom, Germany, and France). Besides the commercial problem, there is a scientific problem: that of enabling simultaneous application (in the same person) in a short sequence of single photon gamma and positron emitters.
Thus far, it seems that there has been no satisfactory solution for a unique design to image both single photon and positron emitters. Contemporary PET scanners with their circumference arrangements of BGO crystals (efficient absorbers of high photon energies of 511 KeV emanating from positron emitters), i.e., of small opposing detectors connected with coincidence electronics, are designed to detect exclusively the positron emitters in a tomography mode. Position sensitive area detectors of the GSC type are made with the thin NaI(TI) crystals for optimal imaging detection of the low energy single photon gamma emitters; here, optimal imaging detection assumes an optimal spatial resolution for energies up to 150 KeV, with a shortage of the detection efficiency for medium and higher energies of single photon gamma emitters (250 and 360 KeV) being significantly reduced. Such a reduced efficiency makes the detection of high energy photon emissions, such as the ones of 511 KeV from positron emitters, difficult or impossible. There is a design of a system made of opposing position sensitive area detectors in coincidence mode fitted with thick (1 inch (in.) for increased efficiency) NaI(TI) crystals, to be used only for tomographic detection of positron emitters (due to the intolerantly worse spatial resolution for lower energies of single photon emitters). The fact, however, that this is also an imager aimed at serving PET exclusively, as well as that in such a system, the optimal spatial resolution for PET has not still been achieved due to the inherent “parallax” error, emphasizes and indicates the need for an imaging system which solves the above mentioned problems.
References which may be of interest include the following, which concern the design of position sensitive GSC type detectors:
U.S. Pat. Nos: 3,011,057; 3,745,345; 3,921,000; 3,943,336; 4,057,725; 4,700,074;
H. O. Anger: Rev. Sci. Inst., 29, 27, (1958);
H. O. Anger: Nucleonics, 21, 10, 56, (1963);
H. O. Anger and D. H. Davis Rev. Sci Inst., 35, 6, 693, (1964);
H. O. Anger: IEEE Trans. Nucl. Sci., 13, 3, 380, (1966); and
G. Muehllehner, et al.: J. Nucl. Med., 21, 771, (1980).
In addition, the following references concern the design of PET scanners based on position sensitive imaging detectors fitted with thick (e.g., 1 in.) NaI(T1i) crystals:
G. Muehllehner, et al.: IEEE Trans. Nucl. Sci., 23, 1, 528, (1976);
J. S. Karp, et al.: IEEE Trans. Nucl. Sci., 33, 1, 550, (1986); and
J. S. Karp, et al.: J. Nucl. Med., 31, 617, (1990).
Finally, the following references concern the design of “classic” PET scanners, mostly fitted with a circumference arrangement of BGO crystals:
M. E. Phelps, et al.: J. Nucl. Med.; 16, 210, (1975);
M. E. Phelps, et al.: IEEE Trans. Nucl. Sci., 23, 516, (1976);
Z. H. Cho, et al.: J. Nucl. Med., 18, 840, (1977);
M. E. Phelps, et al.: J. Nucl. Med., 19, 635, (1978);
E. J. Hoffman, et al.: IEEE Trans. Nucl. Sci., 33, 1, 452, (1986);
E. J. Hoffman, et al.: J. Nucl. Med., 3, 29, 983, (1988).
J. A. Sorenson and M. E. Phelps: Physics in Nuclear Medicine Sec. Edit., Saunders (1987).
SUMMARY OF THE INVENTION
The present invention includes a radiation detector comprising a plurality of scintillation crystal layers and a light collimator system optically coupled to the scintillation crystal layers for determining a depth of interaction associated with a scintillation event. Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.
REFERENCES:
patent: 3011057 (1961-11-01), Anger
patent: 3745345 (1973-07-01), Muehllehner
patent: 3921000 (1975-11-01), Muehllehner
patent: 3943336 (1976-03-01), Dillard et al.
patent: 4057725 (1977-11-01), Wagner
patent: 4272678 (1981-06-01), Lange
patent: 4394576 (1983-07-01), Tanaka et al.
patent: 4675526 (1987-06-01), Rogers et al.
patent: 4677299 (1987-06-01), Wong
patent: 4700074 (1987-10-01), Bosnjakovic
patent: 4733083 (1988-03-01), Wong
patent: 4843245 (1989-06-01), Lecomte
patent: 5122667 (1992-06-01), Thompson
patent: 5349191 (1994-09-01), Rogers
patent: 5585637 (1996-12-01), Bertelsen et al.
patent: 5616924 (1997-04-01), Petrillo
Hal O. Anger, “Scintillation Camera”, The Review of Scientific Instruments, vol. 29, No. 1, Jan., 1958, pp. 27-33.
Hal O. Anger, “Gamma-Ray and Positron Scintillation Camera”, Nucleonics, vol. 21, No. 10, Oct. 1963, pp. 56-59.
Hal O. Anger and Donald H. Davis, “Gamma-Ray Detection Efficiency and Image Resolution in Sodium Iodide”, The Review of Scientific Instruments, vol. 35, No. 6, Jun. 1964, pp. 693-697.
Hal O. Anger, “Sensitivity, Resolution and Linearity of the Scintillation Camera”, IEEE Transaction Nuclear Science, vol. NS-13, No. 3, Jun. 1966, pp. 380-392.
G. Muehllehner, et al., “Correction for Field Nonuniformity in Scintillation Cameras Through Removal of Spatial Distortion”, The Journal of Nuclear Medicine, vol. 21, No. 8, Aug. 1980, pp. 771-776.
G. Muehllehner, et al., “Performance Parameters of a Positron Imaging Camera”, IEEE Transaction on Nuclear Science, vol. NS-23, No. 1, Feb., 1976, pp. 528-537.
Michael E. Phelps, et al., “Application of Annihilation Coincidence Detection to Transaxial Reconstruction Tomography” Journal of Nuclear Medicine, vol. 16, No. 3, Mar. 1975, pp. 210-224.
Michael E. Phelps, et al., Design Considerations for a Positron Emission Transaxial Tomograph (PETT III), IEEE Transations on Nuclear Medicine, vol. NS-23, No. 1, Feb. 1976, pp. 516-522.
Z.H. Cho and M.R. Farukhi, “Bismuth Germanate as a Potential Scintillatio Dectector in Positron Cameras”, Journal of Nuclear Medicine, vol. 18, No. 8, Aug. 1977, pp. 840-844.
Michael E. Phelps, et al., “ECAT: A New Computerized Tomographic Imaging System for Positron-Emitting Radiopharmaceuticals”, The Journal of Nuclear Medicine, vol. 19, No. 6, Jun., 1978, pp. 635-647.
James A. Sorenson, Ph.D. and Michael E. Phelps, Ph.D.,Physics in Nuclear Medicine,1987.
J.S. Karp, et al., “Event Localization in a Continuous Scintillation Detector Using Digital Processing”,IEEE Trans. Nucl. Sci.,vol. 33, No. 1, Feb. 1986, pp. 550-555.
J.S. Karp, et al., “Continuous-Slice PENN-PET: A Positron Tomograph with Volume Imaging Capability,”Journal of Nuclear Medicine,vol. 31, No. 5, May 1990, pp. 617-627.
E.J. Hoffman, et al., “Dynamic, Gated and High Resolution Imaging with the ECAT III,”IEEE Trans. Nucl. Sci.,vol. 33, No. 1, Feb. 1986, pp. 452-455.
E. J. Hoffman, et al., “Performance on a NeuroPET System Employing 2-D Modular Detectors,”Journal of Nuclear Medicine,vol. 29, No. 5, May 1988, pp.
ADAC Laboratories
Blakely & Sokoloff, Taylor & Zafman
Gabor Otilia
Hannaher Constantine
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