Integrated Multi Slice X-ray Detector for In-Line Computed Tomography

Abstract

In accordance with some embodiments of the invention, an x-ray image detector for generating signals in response to an x-ray beam is presented. The x-ray image detector comprises two-dimensional (2D) pixel arrays in a single substrate so that signal from every pixel can be simultaneously collected. A layer of x-ray scintillating material is applied in front of the 2D array. A plurality of detector can be arranged as tiled detector arrays using chip on-board technology. When multiple on-board detectors are arranged and mounted on a curve gantry along with X-ray source on the opposite side, the X-ray detector system is therefore can be used for compact, low cost multi slice in-line CT application. Peripheral circuits can be located in the same substrate or in a different substrate to ensure individual detector signal can be read out parallel.

Claims

1. An X-ray detector comprising: a two dimensional photodiode array coupled to the layer of scintillating material and configured to detect the light output from the scintillating material and generate the analog electrical signals responsive thereto; and a layer of scintillating material to receive x-rays attenuated through the object and generate a light output responsive thereto; and a set of peripheral circuits comprising pixel signal processing circuits, global video signal processing circuits, and timing generators which generate all control clocks necessary for operation of the detector.

2. The X-ray detector of claim 1, wherein the photodiode array is located in the same substrate.

3. The X-ray detector of claim 1, wherein peripheral circuits are located in the same substrate as that of the photodiode array.

4. The X-ray detector of claim 1 wherein the photodiode array is separated from the peripheral circuits on the detector array substrate by a distance sufficient to allow the modulated X-ray beam to impinge on the photodiode array, but not on the peripheral circuits.

5. The X-ray detector of claim 1 wherein: the photodiode array is precisely positioned on the substrate by chip on-board assembly technology to accurately register a position of the photodiode array with respect to the substrate.

6. The X-ray detector described in claim 1 the photodiode array is buttable.

7. The X-ray detector of claim 1 wherein: the peripheral circuits are protected from impingement of the modulated X-ray beam by a metal shield.

8. An X-ray detector comprising: a two dimensional photodiode array coupled to the layer of scintillating material and configured to detect the light output from the scintillating material and generate the analog electrical signals responsive thereto; and a layer of scintillating material to receive x-rays attenuated through the object and generate a light output responsive thereto; and a set of peripheral circuits comprising pixel signal processing circuits, global video signal processing circuits, and timing generators which generate all control clocks necessary for operation of the detector.

9. The X-ray detector of claim 8, wherein peripheral circuits are located in a separate piece of substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows a typical application of X-ray in-line industrial CT using integrated multi-slice detector.

[0034] FIG. 2 shows a multi slice pixel array and their processing circuit in a single substrate.

[0035] FIG. 3 shows a pair of single substrate multi slice pixel arrays is head-to-head assembled.

[0036] FIG. 4 shows a multi slice pixel array and their processing circuit in separate substrates.

[0037] FIG. 5 shows a pair of two-substrate multi slice pixel arrays is head-to-head assembled.

[0038] FIG. 6 shows a basic single substrate multi slice X-ray detector.

[0039] FIG. 7 shows a pair of single substrate multi slice X-ray detector.

[0040] FIG. 8 shows a curved assembly of integrated multi slice X-ray detector.

DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention is a multi line X-ray detector for industrial CT (iCT).

[0042] Multi line structure or multi slice structure is arranged in a substrate as multi slice pixel array 10. Processing circuit 6 can be in the same substrate of integrated sensor array 5 or in a different substrate as processing circuit substrate 9. Total numbers of slices are usually 8, 16, 32 and 64 etc.

[0043] Referring to FIG. 1, a typical implementation of industrial CT using a multi slice X-ray detector is shown. A multi slice X-ray detector comprises scintillating material 4, integrated sensor array 5 and processing circuit 6. X-ray source 1 generates X-ray beam 2. When scan objects 3 pass through X-ray beam 2, the image signal will be registered in the integrated sensor array 4. X-ray source 1 and multi line X-ray detector are in a rotational gantry.

[0044] FIG. 2 shows a basic component of an integrated multi slice X-ray detector. In this detector, multi slice pixel array 10 and processing circuit 6 are in the same substrate of integrated sensor array 7.

[0045] FIG. 3 shows the configuration that would effectively double numbers of slices in a multi slice X-ray detector. In this case, iCT speed will increase with the increase of numbers of lines or slices.

[0046] FIG. 4 shows an alternative implementation of a multi slice X-ray detector. In this detector, multi slice pixel array 10 and processing circuit 6 are in separate substrates. Multi slice pixel array 10 is in pixel array substrate 8 while processing circuit 6 is in processing circuit substrate 9. In this case, connection between Multi slice pixel array 10 and processing circuit 6 is usually through wire bonding.

[0047] FIG. 5 shows the alternative configuration that would double numbers of slices in a multi slice X-ray detector. Also in this case, iCT speed will also increase with the increase of numbers of lines.

[0048] FIG. 6 shows that a scintillating material 4 is attached on the multi slice pixel array 10 area. Scintillating material 4 can be a single piece material such as Gd.sub.2O.sub.2S:Tb (GOS or GADOX), GOS or segmented material like such as CdWO.sub.4 (CWO), or GAGG:Ce (GAGG). Scintillating material 4 usually is glued on the multi slice pixel array 10.

[0049] FIG. 7 shows a multi slice X-ray detector after scintillating material 4 is attached on the area of multi slice pixel array 10. Two separate detectors are placed head-to-head to double numbers of slices

[0050] FIG. 8 shows how a curved-geometry is achieved at iCT detector. The multi slice X-ray detector is then mounted in mechanical structure of a rotational gantry. Because the detectors are in modules so it is easy to replace individual part. The substrate of integrated sensor array 7 is usually placed on other material such as PCB, glass etc.

[0051] With increasing popularity of wireless data acquisition such as 5G, it is possible to build even simpler iCT machine using the invention. Total numbers of multi slice X-ray detector needed to make a curve on a rotational gantry would largely depend on application and X-ray source beam angle.

[0052] The above disclosure is not intended as limiting. Those skilled in the art will readily observe that variations and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the restrictions of the following claims.