IL118383A - Light weight gamma-camera head and gamma-camera assemblies containing it - Google Patents

Description

Light weight γ-camera head and γ-camera assemblies containing it The State of Israel, Atomic Energy n> -»N> ητιηη ,!>N*I¾» JI_»>T» Commission Soreq Nuclear Research *J J>I) ipna ra on n »Wi< Center The inventors; Yosef EISEN Chaim GILAT Giora KEINAN C. 102212 FIELD OF THE INVENTION The present invention is an improvement of and in addition to the invention described and claimed in our IL 105881 (hereinafter "the main invention and "the main patent", respectively). Similar as the main invention, the present invention is in the field of radionuclide imaging. Radionuclide imaging is one of the most important applications of radioactivity in medicine and it aims at obtaining a map of the distribution of radioactivity within an organ of a patient upon injection of a substance that bears a so-called radionuclide, i.e. a radioactive marker. Imaging is obtained with the aid of instruments, referred to in the art as gamma-cameras, which bear detectors for X-rays and gamma-radiation originating from the radioactive marker substance.

The background of the main invention and the prior art are described in detail in the specification of the main patent and that descrip-tion is incorporated herein by reference.

Quite generally and in accordance with claim 1 thereof, the main patent concerns a gamma-camera head having a detector assembly for the detection of X- and gamma-radiation, characterized by: - 2 - 118383/2 (i) said detector assembly comprising an array of room temperature, solid-state spectroscopy grade detectors each associated with a collimator and preamplifier, which detectors and associated collimators and preamplifiers are arranged in parallel rows extending in a first direction and suitably spaced from each other in a second direction normal to said first direction, each of said parallel rows holding a plurality of said room temperature spectroscopy grade solid-state detectors; (ii) electric motor means for moving said detector assembly in said second direction in a controlled fashion.

BRIEF DESCRIPTION OF THE PRESENT IMPROVEMENTS AND MODIFICATIONS While the main patent discloses and claims a mode by which the detectors with their associated collimators and preamplification means are arranged in parallel rows extending in a first direction and suitably spaced from each other in a second direction, it has now been found that the detectors and associated collimators and preamplification means can also advantageously be arranged in form of a two-dimensional monolithic array covering the complete field of view of the camera head.

The preamplification means disclosed in the main patent include preamplifiers and hybrid preamplifier/amplifier devices and it has now been found that in addition to these specific embodiments it is also possible to use for preamplification application specific integrated circuits, if desired with peak sensing or multiplexing.

It has further been found that some modifications can be made to advantage in the collimators. Thus, by one such modification a pinhole collimator is used. By one embodiment one single pinhole collimator is associated with all the detectors of the array. In another embodiment a collimator comprising several pinholes and is used in association with all the detectors of the array.

By another modification the collimator holds a plurality of parallel channels and by yet another modification the collimators are exchangeable. - 3 - 118383/2 The specific solid-state spectroscopy-grade detectors disclosed in the main patent are CdTe, CdZnTe and Hgl2 and it has now been found that in addition Pbl2 detectors can also be used to advantage.

According to yet another modification of the main patent provided in accordance with the present invention, the detectors and associated collimators and preamplifiers are arranged in assemblies each comprising at least two juxtaposed and staggered detector rows and a plurality of such assemblies are arranged in parallel rows extending in a first direction and suitably spaced from each other in a second direction normal to said first direction.

By a still further modification of the main invention that is now provided, the collimators in said parallel rows are converging and thereby adapted for the interception of convergingly propagating gamma-radiation; or alternatively the collimators in said parallel rows are diverging and thereby adapted for the interception of divergingly propagating gamma-radiation.

Yet another improvement of the main invention that is now provided concerns the incorporation of the gamma-camera assembly of means of time delay integration.

The invention also concerns gamma-camera assemblies comprising a gamma-camera head according to any of the present improvements and modifications.

BRIEF DESCRIPTION OF THE DRAWINGS For better understanding the present improvements and modifications of the main invention will hereinafter be described, by way of example only, with reference to the annexed drawings. For the sake of convenience the numbering of the drawings is sequential to that in the main patent and numerals used in the main patent will be used for corresponding parts.

In the drawings: Fig. 10A is an axonometric view of an array constituting row of room temperature spectroscopy grade solid-state detectors and associated collimator for use in a camera head according to the main invention, - 4 - 118383/2 invention which shows a pinhole collimator having one single pinhole; and Fig. 15 is a section through a gamma-camera head according to the invention with exchangeable collimators.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS The description in the main patent is hereby incorporated by reference.

Turning first to Figs. 10A and 10B there is shown an improvement of the camera head according to the main patent, by which each detector plate such as plate 51 in Figs. 6 and 7 of the main patent is associated with a multiple channel collimator 60 having four parallel channels 61, 62, 63 and 64. The total cross-sectional area of channel 60 is equal to that of the detector. With the multiple channel collimator detector unit it is possible to achieve the same solid angle as with a single channel collimator detector unit of the kind shown in Figs. 6 and 7 of the main patent, with however a shorter collimator length whereby the weight of the gamma-camera head according to the invention is further reduced.

Turning now to Fig. 11 there are shown two detector rows 65, 66 juxtaposed and staggered and forming together a detector row assembly 13'

Claims (12)

- 6 - 118383/2 CLAIMS:

1. A gamma-camera head according to the main patent, wherein the detectors and associated collimators and preamplification means are arranged in form of a two-dimensional monolithic array covering the complete field of view of the camera head.

2. A gamma-camera head according to the main patent, wherein said preamplification means is an application specific integrated circuit.

3. A gamma-camera head according to the main patent, wherein the detector collimators are associated with pinhole collimators.

4. A gamma-camera head according to Claim 3, wherein one single pinhole collimator is associated with all detectors of the array.

5. A gamma-camera head according to Claim 3, wherein a collimator with several pinholes is associated with all detectors in the array.

6. A gamma-camera head according to the main patent, wherein each collimator holds a plurality of channels.

7. A gamma-camera head according to the main patent, wherein said solid state, spectroscopy grade detector is Pbl2.

8. A gamma-camera head according to the main patent, wherein the detectors and associated collimators and preamplifiers are arranged in assemblies each comprising at least two juxtaposed and staggered detector rows and a plurality of such assemblies are arranged in parallel rows extending in a first direction and suitably spaced from each other in a second direction normal to said first direction. - 7 - 118383/2

9. A gamma-camera head according to the main patent, wherein the collimators in said parallel rows are converging and thereby adapted for the interception of convergingly propagating oncoming gamma-radiation.

10. A gamma-camera head according to the main patent, wherein the collimators in said parallel rows are diverging and thereby adapted for the interception of divergingly propagating oncoming gamma-radiation.

11. A gamma-camera assembly comprising a gamma-camera head according to any one of Claims 1 to 10.

12. A gamma-camera assembly according to Claim 11 comprising means of time-delay integration. 102212MC.spc/prg 5.6.1996