Patent EP0444324A2 successfully refreshed from Google Patents.
EP0444324A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for removing artifact and for correcting sensitivity of single photon emission computerized tomography and apparatus thereof
Assignee: Toshiba Corp
•
Filing: 1990-12-31
•
Granted: —
•
Expires: 2010-12-31
Abstract
Abstract In a single photon emission computerized tomographic (SPECT) image acquiring method by receiving via a fan-beam collimator (7) radiation emitted from a radio isotope (RI) supplied into a biological body under medical examination with employment of a gamma camera (8), there are provided the steps of: acquring first projection image data by receiving via the fan-beam collimator (7) radiation emitted from reference RI source means (9); processing said first projection image data to obtain first correction data; acquiring second projection image data by receiving via said fan-beam collimator (7) said radiation emitted from said radio isotope injected into the biological body; correcting said second projection image data with said first correction data so as to obtain third projection image data from which an artifact component has been eliminated; and, reconstructing a SPECT image of the biological body under medical examination based upon said third projection image data free from the artifact component.
Inventors
- 👤 Takashi Ichihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 09:49
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1648
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
151 words
A method for acquiring single photon emission computerized tomographic (SPECT) image data by receiving via a fan-beam collimator (7) radiation emitted from a radio isotope (RI) supplied into a biological body under medical examination with employment of a gamma camera (8), comprising the steps of: acquiring first projection image data by receiving via the fan-beam collimator (7) radiation emitted from reference RI source means (9); processing said first projection image data to obtain first correction data; acquiring second projection image data by receiving via said fan-beam collimator (7) said radiation emitted from said radio isotope injected into the biological body; correcting said second projection image data with said first correction data so as to obtain third projection image data from which an artifact component has been eliminated; and, reconstructing a SPECT image of the biological body under medical examination based upon said third projection image data free from the artifact component.
Claim 2
Dependent Claim
27 words
A method as claimed in Claim 1, further comprising the step of: storing said first correction data in a first table memory (5B) as artifact correction data.
Claim 3
Dependent Claim
116 words
A method as claimed in Claim 1 or 2 further comprising the step of: calculating a plurality of fourth projection image data by receiving via the fan-beam collimator (7) radiation emitted from radio isotopes uniformly distributed within an effective field of said gamma cammera (8) so as to obtain SPECT image data of the radio isotopes uniformly distributed within the effective field; processing said SPECT image data of the radio isotopes to obtain second correction data; and correcting said reconstructed SPECT image of the biological body based upon said second correction data, whereby a sensitivity of at least said fan-beam collimator (7) is corrected on said reconstructed SPECT image of the biological body under medical examination.
Claim 4
Dependent Claim
27 words
A method as claimed in Claim 3, further comprising the step of: storing said second correction data in a second table memory (6B) as sensitivity correction data.
Claim 5
Independent Claim
31 words
A method as claimed in any of Claims 1 to 4 wherein said reference RI source means is constructed of an RI source vessel (9) having parallel-positioned flat glass plates (12).
Claim 6
Independent Claim
60 words
A method as claimed in any of Claims 1 to 5 wherein said first projection image data are acquired by receiving via the fan-beam collimator (7), a plurality of radiation emitted from said reference RI source means (9) which is positioned at not only a rotation center of said fan-beam collimator (7), but also a place adjacent said rotation center.
Claim 7
Dependent Claim
147 words
A single photon emission computerized tomographic (SPECT) image apparatus comprising: data acquiring means (2) for acquiring both first projection image data by receiving via a fan-beam collimator (7), first radiation emitted from reference radio isotope (RI) source means (9), and also second projection image data by receiving via the fan-beam collimator (7), second radiation emitted from a radio isotope injected into a biological body under medical examination, with employment of a gamma camera (8); artifact removing means (5) for processing said first projection image data to obtain first correction data, and for correcting said second projection image data based upon said first correction data to obtain third projection image data from which an artifact component has been removed; and, reconstructing means (3) for reconstructing a SPECT image of the biological body under medical examination based on said third projection image data with free from the artifact component.
Claim 8
Dependent Claim
177 words
A single photon emission computerized tomographic (SPECT) image apparatus comprising: data acquiring means (2) for acquiring a plurality of first projection image data by receiving via a fan-beam collimator (7'), a plurality of first radiation emitted from reference radio isotope (RI) source means (9) which is positioned at not only a rotation center of the fan-beam collimator (7') but also a place adjacent the rotation center, and also for acquiring second projection image data by receiving via the fan-shaped collimator (7'), second radiation emitted from a radio isotope injected into a biological body under medical examination, with employment of a gamma camera (8); artifact removing means (5) for processing said plurality of first projection image data to obtain first correction data, and for correcting said second projection image data based upon said first correction data to obtain third projection image data from which an artifact component has been removed; and, reconstructing means (3) for reconstructing a SPECT image of the bilogical body under medical examination based upon said third projection image data free from the artifact component.
Claim 9
Dependent Claim
77 words
A SPECT image apparatus as claimed in Claim 7 or 8, wherein said artifact removing means (5) includes: a first table memory (5B) for storing therein said first correction data as artifact correction data; and, a first image data processing unit (5A) for processing said second projection image data with the artifact correction data based upon a first predetermined arithmetic calculation manner, thereby obtaining said third projection image data from which the artifact component has been eliminated.
Claim 10
Dependent Claim
70 words
A SPECT image apparatus as claimed in any of Claim 7 to 9, wherein said reference radio isotope source means (9) used for removing the artifact component from the second projection image data is arranged by at least a vessel (13) constructed of a vessel body (11) and two sets of parallel-positioned flat glass plates (12) for sandwiching the reference radio isotopes within the vessel (13) having a constant thickness.
Claim 11
Dependent Claim
39 words
A SPECT image apparatus as claimed in any of Claim 7 to 10, wherein said reference radio isotope source means (9) further employs two sets of valves (14:15) through which both the reference radio isotopes and water are injected.
Claim 12
Dependent Claim
115 words
A SPECT image apparatus as claimed in any of claim 7 to 11, further comprising: sensitivity correcting means (6) for calculating a plurality of fourth projection image data by receiving via the fan-beam collimator (7), radiation emitted from radio isotopes uniformly distributed within an effective field of said gamma camera (8) so as to obtain SPECT image data of the radio isotopes uniformly distributed within the effective field, for processing the SPECT image data to produce second correction data, and for correcting said reconstructed SPECT image data of the biological body based upon the second correction data, whereby a sensitivity of at least said fan-beam collimator (7) is corrected on said reconstructed SPECT image data.
Claim 13
Dependent Claim
64 words
A SPECT image apparatus as claimed in Claim 12, wherein said sensitivity correcting means (6) includes: a second table memory (6B) for storing therein said second correction data as sensitivity correction data; and, a second image data processing unit (6A) for processing said reconstructed SPECT image data of the biological body so as to sensitivity-correct said reconstructed SPECT image data of the biological body.
Claim 14
Dependent Claim
26 words
A SPECT image apparatus as claimed in Claim 12, or 13, wherein the number of said fourth projection data is selected to a division of 360.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.