System for quantitative radiographic imaging

• US 20020070365A1
• Filed: 06/29/2001
• Published: 06/13/2002
• Est. Priority Date: 12/05/1989
• Status: Active Grant

• Current Assignee: University Of Massachusetts
• Original Assignee: University Of Massachusetts
• Inventors: Karellas, Andrew
• Granted Patent: US 6,717,174 B2
• Time in Patent Office: Days
• US Class Current: 250/581
• CPC Class Codes: A61B 5/0091 for mammography
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/405 Source units specially adapted to modify characteristics of the beam during the data acquisition process A61B6/4021, A61B6/4035 take precedence
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/4423 related to hygiene or sterilisation
• CPC Class Codes: A61B 6/4488 Means for cooling A61B6/045 takes precedence
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: A61B 6/505 for diagnosis of bone
• CPC Class Codes: A61B 6/508 for non-human patients
• CPC Class Codes: A61B 6/512 Intraoral means
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

A system for spectroscopic imaging of bodily tissue in which a scintillation screen and a charged coupled device (CCD) are used to accurately image selected tissue. An x-ray source generates x-rays which pass through a region of a subject'"'"'s body, forming an x-ray image which reaches the scintillation screen. The scintillation screen reradiates a spatial intensity pattern corresponding to the image, the pattern being detected by a CCD sensor. The image is digitized by the sensor and processed by a controller before being stored as an electronic image. Each image is directed onto an associated respective CCD or amorphous silicon detector to generate individual electronic representations of the separate images.

Claims

1. An apparatus for examining a region of a patient comprising:

an x-ray radiation source that directs radiation through the region;

an optical storage element that receives radiation transmitted through the region at a storage region of the optical storage element, the storage region having a two dimensional surface area;

a light source that illuminates the two dimensional surface area of the storage region of the optical storage element to induce a fluorescence emission of an image of the region from the storage region;

a two dimensional detector array optically coupled to the optical storage element such that the array receives the fluorescence emission at a plurality of pixels and generates an electronic representation of the tissue; and

a two dimensional optical coupling system that couples the image of the region onto the two dimensional detector array.

2. The apparatus of claim 1 wherein the optical storage element comprises a photostimulable phosphor.

3. The apparatus of claim 1 wherein the light source further comprises a laser.

4. The apparatus of claim 1 wherein the light source further comprises a broadband light source.

5. The apparatus of claim 1 further comprising a cassette that contains the optical storage element.

6. The apparatus of claim 1 wherein the two dimensional optical coupling system comprises a thin film filter.

7. The apparatus of claim 1 wherein the light source is stationary relative to the optical storage element during illumination.

8. The apparatus of claim 1 wherein the optical coupling system comprises a fiberoptic device.

9. The apparatus of claim 1 wherein the optical coupling system comprises an image intensifier.

10. The apparatus of claim 1 wherein the optical coupling system comprises a lens.

11. The apparatus of claim 1 further comprising a spatial light modulator between the light source and the optical storage element.

12. The apparatus of claim 1 wherein the detector comprises a charge coupled device.

14. The method of claim 13 wherein the optical storage element comprises a photostimulable phosphor.

15. The method of claim 13 wherein the pulse of light is produced by a light source comprising a broadband light source.

16. The method of claim 13 wherein the optical storage element is contained in a cassette.

17. The method of claim 13 further comprising optically coupling the optical signal to the detector array with an optical element.

18. The method of claim 17 further comprising filtering the optical signal with the optical element.

19. The method of claim 17 further comprising intensifying the optical signal with an image intensifier.

13. A method for examining tissue of a patient comprising the steps of:

directing x-ray radiation through the tissue of the patient to produce a radiation pattern that is transmitted onto an optical storage element, such that the optical storage element receives two dimensional radiation pattern representative of the spatial distribution and intensity of the radiation pattern;

directing light onto the optical storage element to produce an optical signal representative of the spatial distribution and intensity of the radiation pattern; and

receiving the optical signal on a two dimensional detector array comprising a plurality of pixels and generating an electronic representation of the tissue.

20. An apparatus for examining a patient'"'"'s spine comprising:

an x-ray radiation source emitting radiation which is directed through the spine;

an optical storage element having a surface area that receives the radiation transmitted through the spine;

a detector into which the optical storage element can be mounted comprising a detector array; and

a light source that can be optically coupled to the surface area of the optical storage element to stimulate the optical storage element to produce an optical signal that is transmitted onto the detector array.