JPWO2020161581A5 - - Google Patents

Description

The present invention relates to a tunnel computed tomography scanner and a method of acquiring images from a scintillator of a tunnel computed tomography scanner.

As is known, tomographic scanners are divided into two main families with respect to the X-ray detector technology used. namely, tomographic scanners with linear sensors (which can be monoline or multiline) and tomographic scanners with panel sensors.

The first family of tomographic scanners is primarily used in the medical field. Compared to the second family of tomographic scanners, the first family of tomographic scanners has lower resolution but higher acquisition frequency.

In contrast, the second family of tomographic scanners is heavily used in industry. Compared to the first family of tomographic scanners, the second family of tomographic scanners has higher resolution and lower acquisition frequency. They have a limited field of view.

Both types of sensors are very expensive. Sensor cost often accounts for more than half of the total cost of a computed tomography scanner.

The present invention has been developed with respect to tomography scanners for industrial use, particularly tunnel tomography scanners. In these tomographic scanners, tomographic examination of an object is performed while the object is being conveyed continuously (often at a relatively high feed rate) through the detection zone of the tomographic scanner.

In order to obtain a correct tomographic reconstruction of the internal structure of an object, X-ray images of the object itself must be acquired from different angular positions in relatively small acquisition steps, at least through a rotation of 180° around the object (second 180° is symmetrical). The main challenge that arises in industrial applications is then to successfully produce tomographic scanners with large acquisition surfaces and an acquisition frequency equal to that of multi-line systems, yet at a much lower cost than the prior art. It is to let

Currently, all prior art sensors are based on the use of scintillator materials that are capable of converting X-rays (X-photons) impinging on the sensor into light photons in the visible spectrum. A panel of cells made of scintillator material is arranged to intercept the X-rays as they pass through the detection zone. The panel comprises an exit surface coupled to a panel of photodiodes (or other device capable of converting light into electricity) from which visible light photons are emitted. In particular, each cell of a scintillator panel is usually provided with a photodiode.

The analog electrical signals generated by the photodiodes are then converted into digital signals and conveyed to a processing unit (usually a computer) for processing.

The most expensive component of prior art detectors is the system that collects high frequency data from a large number of photodiodes.

In this context, the technical object underlying the invention is to provide a tunnel computed tomography scanner and a method for acquiring images from a scintillator of a tunnel computed tomography scanner, which overcomes the above-mentioned drawbacks. be.

In particular, the technical objectives of the present invention are to use a large acquisition surface, have an acquisition frequency equal to that of prior art multiline systems, have an acquisition frequency equal to that of prior art multiline systems, and have an acquisition frequency equal to that of prior art multiline systems; It is an object of the present invention to provide a tunnel computed tomography scanner and a method of acquiring images from a scintillator of a tunnel computed tomography scanner that is lower in cost than that of a tunnel computed tomography scanner.

The stated technical objects and aims are achieved by a tunnel computed tomography scanner and a method for acquiring images from a scintillator of a tunnel computed tomography scanner substantially according to the appended claims. .

Further features and advantages of the invention reside in the detailed description of preferred non-limiting embodiments of a tunnel computed tomography scanner, with reference to the accompanying drawings, and the detailed description of preferred, non-limiting embodiments of a tunnel computed tomography scanner, and images from the scintillator of the tunnel computed tomography scanner. It will be clearer in the detailed explanation on how to obtain .

1 is a schematic front view of a computed tomography scanner manufactured according to the invention; FIG. 2 is a schematic transparent front view showing only the rotor of the tomographic scanner of FIG. 1; FIG. 1 is a schematic illustration of a first embodiment of an X-ray detector that is part of a tomography scanner according to the invention; FIG. 1 is a schematic diagram of a second embodiment of an X-ray detector that is part of a tomography scanner according to the invention; FIG. 3 is a schematic illustration of a third embodiment of an X-ray detector that is part of a tomographic scanner according to the invention; FIG. FIG. 3 is a schematic diagram of a fourth embodiment of an X-ray detector that is part of a tomography scanner according to the invention;

Referring to the above-mentioned drawings, reference numeral 1 generally designates a tunnel-type computed tomography scanner 1 according to the invention.

The tunnel-type computed tomography scanner 1 according to the present invention first includes a support structure 2 functioning as a stator, a rotor 3 supported by the support structure 2, and a rotation drive of the rotor 3 about a rotation axis with respect to the support structure 2. A motor (not shown) connected to the rotor 3 is provided in order to Inside the rotor 3 there is a detection zone 4 through which the rotation axis passes.

Advantageously, in a preferred embodiment, the transport device 5 (which may or may not be part of the tomographic scanner 1) transporting the object 6 is moved during the rotation of the rotor 3 about the axis of rotation. , is mounted through the detection zone 4 in order to feed the object 6 parallel to the axis of rotation. Preferably, at least in the detection zone 4, the transport device 5 for transporting the object 6 is made of a non-radio-opaque material.

The tomographic scanner 1 also comprises an X-ray emitter 7 and an X-ray detector 8 mounted on the rotor 3 on opposite sides of the detection zone 4 .

The X-ray emitter 7 can be of any type suitable for its purpose. (This is known per se and therefore will not be explained in detail.)

In a known manner, the X-ray detector 8 is able to convert the intensity of the X-rays impinging on the X-ray detector 8 into an image in the visible spectrum representing a map of the density of the material through which the X-rays have passed. This is typically an image that can be shown in grayscale. In this image, lighter shades correspond to lower density values. Darker shades correspond to higher density values. The image is also typically defined as the attenuation of the light intensity detected during the measurement compared to the detectable no-load intensity at each pixel. It should be understood that this also applies to the first and second images defined below.

An electronic processing unit (not shown) is then connected to the X-ray detector 8 to reconstruct the three-dimensional structure of the object 6 placed in the detection zone. The first images are programmed to be combined at a plurality of distinct angular positions of the rotor 3 about the axis of rotation. In the context of the present invention, a defined main image or first image refers to the overall image representing the visible light emitted by the entire scintillator.

X-ray detector 8 includes at least one scintillator 9. The scintillator 9 comprises a two-dimensional matrix of cells arranged side by side in a known manner. Each cell contains scintillation material and is separated from adjacent cells by a thin wall of x-ray shielding material.

The scintillator 9 defines at least one exit surface 10 corresponding to a portion of its outer surface. When the scintillator 9 is hit by an X-ray (the X-ray beam is represented by a long dashed line in the attached figure), it emits light in the visible spectrum from an exit surface 10 that must be used to create a tomographic image. radiate.

Advantageously, both the entire scintillator 9 and its exit surface 10 are flat. However, they may also consist of two or more parts arranged obliquely to each other (FIG. 5).

In general, the exit surface 10 can be oriented either toward the X-ray emitter 7 (FIG. 5) or toward the opposite side of the X-ray emitter 7 (FIGS. 3 and 4). The latter is the solution usually adopted in prior art tomographic scanners. However, the former solution, in which the exit surface 10 coincides with the plane on which the X-rays strike the scintillator 9, is devised taking into account the fact that most scintillator materials are only partially transparent to visible light. . As a result, they can only be manufactured in limited thicknesses in order to reduce the risk that the light generated by the interaction of X-rays with the scintillator 9 is absorbed by the scintillator 9 itself. At the same time, if the thickness is too thin, a significant proportion of the incident X-rays cannot be captured en route. The solution of using the light emitted by the scintillator 9 on the same side as the X-ray source (FIG. 5) increases the efficiency of the system. This is because most of the X photons are intercepted by the first layer of material of the scintillator 9 and have to pass through less of the scintillator 9 before exiting the exit surface 10. (Note that visible light photons are emitted in all directions). Several tests carried out by the applicant have demonstrated that in this way, other things being equal, it is possible to obtain approximately twice the usable light intensity.

However, depending on the embodiment, only one exit surface 10 is arranged on one side of the scintillator 9 only, or on two opposite sides of the scintillator 9 (i.e. two sides of each cell of the scintillator 9). There may be two exit surfaces 10. In particular, in a more complex embodiment (FIG. 6), the scintillator 9 comprises two flat scintillator bodies 11. These scintillator bodies 11 are connected to each other parallel to their respective extending planes. The scintillator bodies 11 each constitute an exit surface 10 . In particular, one of the two exit surfaces 10 faces toward the X-ray emitter 7, and the other faces in the opposite direction. Each scintillator body 11 is divided into cells like the entire scintillator 9. The two scintillator bodies 11 are connected so that corresponding cells are aligned with each other.

In this way, by detecting the light emitted from both sides of the scintillator 9 , two mirror images of the same object 6 can be obtained. Note that the image created by observing the exit surface 10 facing opposite to the X-ray emitter 7 is mainly formed by X photons with higher energy. This is because lower energy X photons are generally blocked by the scintillator body 11 placed on the same side as the X-ray emitter 7. In some embodiments, the electromagnetic spectrum of the detected X-ray photons may be further differentiated by interposing a sheet of X-ray filter material (e.g., aluminum or copper) between the two scintillator bodies 11. It is possible. The principle of using two images based on X photons with different energies is the same as that used in "dual energy" sensors. This allows for improved differentiation of the compositions of the materials being measured.

According to the main innovative aspect of the invention, the X-ray detector 8 also comprises a plurality of video cameras 12 connected to an electronic processing unit. Each video camera 12 includes an acquisition sensor (not shown) and a taking lens 13 optically coupled to the acquisition sensor. The photographing lens 13 focuses (or is capable of focusing) on the exit surface 10 of the scintillator 9 to be observed by the video camera 12. (Preferably, the photographing lens 13 has an optical axis arranged perpendicular to the exit surface 10.)

Advantageously, according to known technology for video cameras 12, the acquisition sensor is a CCD or CMOS sensor. However, other types of sensors, even new generation sensors, can be used if desired. CCD or CMOS sensors typically used in video cameras 12 can acquire data from millions of pixels at very high acquisition frequencies. At the same time, although sensors of this kind can perform this operation efficiently, they are surface is very small. However, a video camera 12 equipped with a lens that frames the scintillator 9 in the viewfinder from an appropriate distance is also capable of framing a fairly large zone and can compensate for the size difference.

Therefore, each video camera 12 is arranged so as to frame at least one portion of the scintillator 9 at the exit surface 10 (or one exit surface 10 among the plurality of exit surfaces 10). Specifically, each video camera 12 is used to successively acquire images in the visible spectrum of a zone of the exit surface 10 corresponding to a particular portion of the scintillator 9. In the context of the present invention, the individual images captured by each video camera 12 are defined as working images or second images. Advantageously, a working image is acquired each time the rotor 3 is in an angular position where processing of the main image is required.

Also, according to the main innovative aspect of the invention, each section of the scintillator 9 transmits a greater amount of photons to each section of the scintillator 9 than could be achieved with a single video camera 12. The images are captured by at least two separate video cameras 12. In practice, the visible light emitted by the scintillator 9 can be collected by collecting the visible light emitted by the scintillator 9 using a lens placed at some distance, rather than using direct coupling as in current solutions using photodiodes. The disadvantage is that most of the light photons coming out of the lens do not reach the lens and are therefore dispersed. This makes the signal detectable by the video camera 12 very weak, thus reducing the signal-to-interference ratio.

At least in industry, the use of X-ray emitters with higher power and voltage than prior art tomography scanners, high gain and low noise video cameras to increase the strength of the signal detectable by the video camera 12 12, using a video camera 12 that is cooled to reduce the effects of thermal noise, or coupling one or more lenses to the exit surface 10, the light emitted by the exit surface 10 can be transferred to the video camera 12. Other devices can also be used to focus.

Furthermore, it is also possible to use a lens with a very wide aperture (eg, with an aperture value less than f/1, such as f/0.95) to collect more light. It should be noted that these lenses have a very narrow depth of field. However, as long as the framed portion of the exit surface 10 is flat and perpendicular to the optical axis of the lens of the video camera 12, this is not a problem. In fact, in this way the required depth of field can even be reduced to zero.

Please note the following: That is, when there is only one exit surface 10, by framing the same zone of the exit surface 10 multiple times, the same portion of the scintillator 9 can be framed multiple times. On the other hand, when there are two opposing exit surfaces 10 (FIG. 6), even if two video cameras 12 are used for framing, one on one exit surface 10 and the other on the other exit surface 10, the scintillator 9 You can frame the same part twice. (In FIG. 6, each portion is framed four times by two video cameras 12 on one exit surface 10 and two video cameras 12 on the other exit surface 10.)

The electronic processing unit then advantageously combines all the second images acquired by the video cameras 12 and, in particular, advantageously a plurality of second images acquired by different video cameras 12 for each part of the scintillator 9. , by summing each first image, or by averaging them.

Thanks to the fact that the images to be detected are generated in the plane of the scintillator 9, it is possible to acquire images with video cameras 12 located at different points without possible ambiguities. In fact, the amount of light sent in different directions by the scintillator 9 may be different, but is always proportional to the number of X photons hitting each cell of the scintillator 9. Detection by the video cameras 12 is therefore performed by acquiring an "unloaded" image with each video camera 12, i.e. with no object 6 in the detection zone 4 (or with no permanent presence, such as a transport device 5). It can be easily equalized by considering the ratio of the measured signal to the signal acquired without load as the attenuation.

From a geometric point of view, if several video cameras 12 are used to acquire images of superimposed zones, the correct association between the pixels of the images acquired by each video camera 12 (and therefore the correct An initial calibration is required to allow correct association with the cell. This can be done, for example, in two steps. (a) Typical for the calibration of the video camera 12 by acquiring an image of a chessboard or other pattern placed on the scintillator 9, allowing each pixel to be uniquely mapped to a point in the plane; steps that make the procedure applicable. (b) acquired by a combination of the signals of all video cameras 12 by scanning an object 6 (e.g. a group of steel balls with a known diameter of e.g. 1 mm, placed in a known position with respect to each other) To ensure that the reconstruction provides as accurate a sphere as possible, or equivalently, that the back projections of the spheres identified in each video camera 12 image converge to the same point in space. A step of optimizing the geometrical parameters of the system to ensure that.

Depending on the embodiment, each video camera 12 has an exit surface 10 in its entirety (FIGS. 3, 4, and 6) or only a portion thereof (in FIG. ) can be framed.

In a preferred embodiment, in order to facilitate the operation of the subsequent tomographic reconstruction, the electronic processing unit advantageously provides an exit surface 10 that can be acquired by using a single sensor with characteristics of the prior art. It is programmed to combine the second images in such a way as to obtain a first image that corresponds to the entire image. Given the images received from a variety of video cameras 12, in order to proceed with the tomographic inversion, it is preferred in practice to generate a virtual image as if it were acquired by a single virtual sensor. It is. The definition of the parameters of the recreated virtual sensor (curved or flat, resolution, extent) may be arbitrary, but is preferably as similar as possible to that measured by the video camera 12. Katsevich (Katsevich, Alexander “Theoretically exact filtered backprojection-type inversion algorithm for spiral CT”, SIAM Journal on Applied Mathematics 62.6 (2002): 2012- In some known tomographic inversion algorithms, such as the one proposed by (2026), one of the first operations required is to calculate the readings when the sensor is placed along several special curves. Note that it is "forward height rebinning" which requires calculation of wax values. In that case, it would be advantageous for the pixels of the virtual sensor recreated during the first image generation to match those required in the first step of the algorithm.

Similar to the tomographic scanners of the prior art, means 6 according to the invention are provided for determining the angular position of the rotor 3 about the axis of rotation at the moment the second image is acquired. (In practice, tomographic reconstruction is only possible by knowing exactly the angular position referenced by each first image acquired). Regarding the prior art means of determining the angular position (based on the exact movement of the rotor 3), no details will be given. In an innovative embodiment of the invention, the means for determining the angular position of the rotor 3 are constituted by an electronic processing unit which is also programmed to determine the angular position. The electronic processing unit processes the first image depending on the known position of one or more fixed reference elements present in the detection zone 4 . This embodiment is particularly useful when using a video camera 12 that does not have a digital input to obtain information regarding angular position. The proposed solution consists in using the image generated on the scintillator 9 (and thus in the first image) by a plurality of known features of the detection zone 4, in particular by the transport system, in order to calculate the angular position. Become. For example, it is possible to use a support surface that may be present for the conveyor belt of the transport device 5 transporting the objects 6. It defines a plane that, when aligned with the X-ray, creates very sharp light and dark edges in the image. By observing the gradient of the image produced by these reference elements over time, we determine the frame in which the plane aligns with the ray (e.g. by calculating the maximum point of a parabola on a gradient/frame graph). It is possible to estimate with an accuracy equal to at least 1/10.

Regarding this method of determining the angular position of the rotor 3, the applicant reserves the right to pursue independent protection even by filing a divisional application.

The communication system between the rotor 3, which rotates at relatively high speed, and the static part of the system (support structure 2) can be complex, expensive and provides very high data communication bandwidth. I can't. It is therefore advantageous to divide the electronic processing unit into two or more main units programmed to carry out separate processing divided between the stator part and the rotor 3. In particular, there are one or more rotor main units mounted on the rotor 3 and connected directly to the video camera 12 and one or more stator main units stationary with respect to the rotation of the rotor 3. can. In particular, it may be advantageous for the rotor main unit to be directly inside one or more video cameras 12.

In some embodiments where the exit surface 10 is arranged on the side opposite the X-ray emitter 7, as shown in FIG. Also provided is an angled mirror 14 and/or a protective shield 15 (for example lead glass) for protection against X-rays, arranged along.

In reality, most of the X photons hitting the scintillator 9 are not converted into light and proceed on that path. If the video camera 12 had been placed directly after the scintillator 9, they would have been damaged. By interposing a protective shield 15 or an angled mirror 14 (with respect to the direction of the x-rays), or both, this problem can be avoided. By using angled mirror 14, video cameras 12 can be placed in a lateral position where they are much easier to shield. Additionally, the arrangement of the angled mirror 14 can also limit the distance between the video camera 12 and the center of rotation. The centrifugal force experienced by the video camera 12 and everything associated with it (lens, cables, connectors, supports, shields) depends linearly on the distance from the center of rotation, and since the speeds are the same, this is important. The greater the centrifugal force that can be generated, the greater the need to use powerful (and expensive) components and the more complex the design.

Otherwise, in the case of a solution in which the video camera 12 observes the exit surface 10 facing the X-ray emitter 7, no mirror or shield is necessary. This is because the video camera 12 can simply be placed laterally (Fig. 5) to prevent it from being hit by the direct beam of X-rays, and in any case the position of the video camera 12 may be rotated. This is because I think it is probably not that far from the center.

Additionally, with the aim of increasing the sensitivity of the video camera 12, in some embodiments, at least one video camera 12 has a detection pixel (each video camera 12 comprises a plurality of detection pixels - numbered in millions). ) are grouped into a plurality of groups each comprising at least two pixels. The detection of each group of pixels is integrated into a single readout. In this way, it is possible to virtually increase the size of each individual output pixel, thus collecting more photons. For example, pixels can be grouped based on square patterns with sides of 2×2, 3×3, 4×4, . . . N×N. Technically, this can be done within the video camera 12 itself using binning or through software on the computer that processes the images. By dividing the zone to be framed ( exit surface 10) into sub-zones, each covered by two or more video cameras 12, each video camera 12 has a small number of pixels, each corresponding to a large number of unified real pixels. It is also possible to cover large zones with high resolution even when providing an output with virtual pixels of .

Next, a method of acquiring an image from the scintillator 9 of the tunnel-type computed tomography scanner 1 will be explained. The method comprises a plurality of operating steps performed on the X-ray detector 8 described above from a structural point of view. Where applicable, what has been described with reference to the tomography scanner 1 must also be considered valid for this method. The reverse is also true.

The method first comprises the steps of framing the same zone of the exit surface 10 with at least two separate video cameras 12 for each part of the scintillator 9 whose images are to be acquired; generating, with each video camera 12 framing each zone of the exit surface of the zone, a second image of the zone.

There is then a step of combining, using an electronic processing unit, the second images obtained for the various parts of the scintillator 9 in order to obtain a single first image representing the entire scintillator 9.

In a preferred embodiment, the step of combining the second images is a step of summing, for each zone of the exit surface 10 of the scintillator 9, the second images associated with that zone, or a step of summing the second images associated with that zone. including any of the steps of the averaging operation.

The invention provides important advantages.

Indeed, thanks to the invention, we provide a tunnel computed tomography scanner 1 that has an acquisition frequency equal to that of prior art multi-line systems, is lower in cost than those of the prior art, and uses a larger acquisition surface. In addition, it has become possible to provide a method for acquiring images from the scintillator 9 of the tunnel type computed tomography scanner 1.

Finally, it should be noted that the invention is relatively easy to manufacture and even the costs associated with implementing the invention are not very high.

The invention described above can be varied and adapted in a number of ways. Thereby, the invention described above does not depart from the scope of the inventive concept.

All details can be replaced by other technically equivalent elements. The materials used, as well as the shapes and dimensions of the various components, can be varied depending on requirements.

Claims (19)

A tunnel computed tomography scanner,
a support structure (2);
A rotor (3) supported by the support structure (2) and rotatable about a rotation axis relative to the support structure (2), the rotor (3) having a detection zone ( a motor connected to the rotor (3) to rotate the rotor (3) around a rotation axis;
an X-ray emitter (7) attached to the rotor (3);
In the rotor (3), an X-ray detector (8) is attached to the side opposite to the X-ray emitter (7 ) across the detection zone (4), the X -ray detector (8) having at least one exit surface ( 10) , comprising at least one scintillator (9) which emits light in the visible spectrum from said exit surface (10) when struck by X-rays;
an electronic processing unit connected to said X-ray detector (8) for reconstructing a three-dimensional structure of an object (6) placed in said detection zone (4); an electronic processing unit programmed to combine the first images acquired by 8) at a plurality of distinct angular positions of said rotor (3) about an axis of rotation;
Said X-ray detector (8) also comprises a plurality of video cameras (12) connected to said electronic processing unit, each video camera (12) at each of said distinct angular positions of said rotor (3). , arranged to frame at least one portion of the scintillator (9) to obtain a second image of the visible spectrum of the respective portion of the scintillator (9);
Of the plurality of video cameras (12) , at least two separate video cameras (12) substantially frame each zone of the at least one exit surface (10) of the scintillator (9) and A tunnel computed tomography scanner, wherein the unit is programmed to acquire each first image by combining all second images acquired by said video camera (12). Tunnel computed tomography scanner according to claim 1, characterized in that the electronic processing unit acquires for each zone of the at least one exit surface (10) of the scintillator (9) by a different video camera (12). The tunnel computed tomography scanner is programmed to acquire each first image by either summing or averaging a plurality of second images. Tunnel computed tomography scanner according to claim 1 or 2, wherein the electronic processing unit is configured to generate an image of the entire exit surface (10) that can be acquired by using a single sensor with known characteristics. The tunnel computed tomography apparatus is also programmed to combine the second images to obtain a corresponding first image. Tunnel computed tomography scanner according to any one of claims 1 to 3, comprising means for determining the angular position of the rotor (3) about the axis of rotation at the moment the second image is acquired. A tunnel computed tomography scanner is also provided. Tunnel computed tomography scanner according to claim 4, wherein the means for determining the angular position of the rotor (3) comprises one or more fixed reference elements present in the detection zone (4). A tunnel computed tomography scanner, comprising said electronic processing unit programmed to determine an angular position by processing a first image according to a known position of the tunneling computer tomography scanner. Tunnel computed tomography scanner according to any one of claims 1 to 5, wherein the electronic processing unit is mounted on the rotor (3) and directly connected to the video camera (12). divided into two or more main units, one or more rotor main units and one or more stator main units stationary with respect to the rotation of said rotor (3); said two or more main units; A tunnel computed tomography scanner in which the unit is programmed to perform separate processing. Tunnel computed tomography scanner according to any one of claims 1 to 6, wherein each video camera (12) comprises an acquisition sensor and a taking lens (13) optically coupled to said acquisition sensor. A tunnel-type computed tomography scanner, comprising: the taking lens (13) focusing or being able to focus on the exit surface (10) of the scintillator (9). 8. A tunnel computed tomography scanner according to claim 7, wherein the acquisition sensor is a CCD or CMOS sensor. 9. The tunnel type computed tomography scanner according to claim 7 or 8, wherein the exit surface (10) of the scintillator (9) is flat, and the photographing lens (13) is arranged in a direction opposite to the exit surface (10). A tunnel-type computed tomography scanner with a vertically oriented optical axis. Tunnel computed tomography scanner according to any one of claims 1 to 9, wherein the X-ray detector (8) extends from the main surface to the one or more video cameras (12). A tunnel computed tomography scanner also comprising an angled mirror (14) and/or a protective shield (15) for protection against X-rays, arranged along the optical path of the tunnel. Tunnel computed tomography scanner according to any one of claims 1 to 10, wherein each video camera (12) comprises a plurality of detection pixels, in at least one video camera (12) said detection pixel A tunnel computed tomography scanner that is grouped into a plurality of groups each comprising at least two pixels, and the detection of the pixels of each group is integrated into a single readout. Tunnel computed tomography scanner according to any one of claims 1 to 11, wherein the X-ray detector (8) transmits the light emitted by the exit surface (10) to the video camera (12). ). A tunnel computed tomography scanner also comprising one or more lenses coupled to said exit surface (10) for focusing. Tunnel computed tomography scanner according to any one of the preceding claims, wherein the video camera (12) is cooled. Tunnel computed tomography scanner according to any one of claims 1 to 13, wherein the exit surface (10) of the scintillator (9) faces the X-ray emitter (7). Type computed tomography scanner. Tunneling computed tomography scanner according to any one of claims 1 to 13, wherein the scintillator (9) comprises two flat scintillator bodies (11) connected together , the scintillator (9) comprising two planar scintillator bodies (11) connected to each other. (11) each constitute an exit surface (10), two said exit surfaces (10), one facing said X-ray emitter (7) and the other facing in the opposite direction, said at least two separate a video camera (12) frames each zone of each exit surface (10), and said electronic processing unit frames each first A tunnel computed tomography scanner that is programmed to acquire images. Tunnel computed tomography scanner according to claim 15, wherein each of the first group of video cameras (12) of the plurality of video cameras (12) covers at least one zone of one exit surface (10). and each of the second group of video cameras (12) of the plurality of video cameras (12) is arranged to frame at least one zone of the other exit surface (10). A tunnel-type computed tomography scanner. Tunnel computed tomography scanner according to any one of claims 1 to 16, further comprising a transport device (5) for transporting the object (6), said transport device (5) being centered around a rotation axis. A tunnel computed tomography scanner mounted through the detection zone (4) to feed an object (6) parallel to the axis of rotation during rotation of the rotor (3). A method of acquiring an image from a scintillator (9) of a tunnel-type computed tomography scanner (1), wherein an exit surface (10) of the scintillator (9) is configured to emit a visible spectrum when X-rays impinge on the scintillator (9). emitting light of
for substantially each zone of the exit face (10) of the scintillator (9) for which an image is to be acquired, framing said zone with at least two separate video cameras (12);
generating a second image of said zone with each video camera (12) framing each zone of said exit surface (10) of said scintillator (9);
combining the second images using an electronic processing unit to obtain a single first image representing the entire scintillator (9). 19. The method according to claim 18, wherein the step of combining the second images comprises, for each zone of the exit surface (10) of the scintillator (9), an act of summing the second images associated with the zone. or of averaging a second image associated with said zone.