JP7486939B2 - X-ray detector and X-ray CT device - Google Patents

Description

Embodiments of the present invention relate to an X-ray detector and an X-ray CT device.

In recent years, with the increasing number of rows in X-ray detectors, sequential acquisition DAS (Data Acquisition Systems) have come to be used in CT (Computed Tomography) scans. A sequential acquisition DAS sequentially acquires X-ray signals detected by multiple detection elements while shifting the timing for each detection element. For example, a sequential acquisition DAS shares one A/D converter among multiple elements and performs A/D conversion sequentially. This allows one A/D converter to process signals from multiple detection elements, reducing the number of A/D converters relative to the number of detection elements.

JP 2011-56325 A

The problem that this invention aims to solve is to properly perform sequential acquisition in an X-ray detector that uses a module composed of multiple detection elements.

The X-ray detector of the embodiment includes a plurality of detection arrays, a control unit, and a processing unit. The plurality of detection arrays includes a plurality of detection elements. The control unit controls the plurality of detection arrays to change the readout timing of the detection elements. The processing unit processes signals from the plurality of detection elements.

FIG. 1 is a block diagram showing an example of the configuration of an X-ray CT apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of the X-ray detector according to the first embodiment. FIG. 3 is a diagram showing an example of a circuit configuration of the X-ray detector according to the first embodiment. FIG. 4A is a diagram showing an example of a read order according to the first embodiment. FIG. 4B is a diagram showing an example of a circuit configuration of the X-ray detector according to the first embodiment. FIG. 5A is a diagram showing an example of a read order according to the first embodiment. FIG. 5B is a diagram showing an example of a circuit configuration of the X-ray detector according to the first embodiment. FIG. 6A is a diagram showing an example of a read order according to the first embodiment. FIG. 6B is a diagram showing an example of a circuit configuration of the X-ray detector according to the first embodiment. FIG. 7A is a diagram showing an example of a read order according to the first embodiment. FIG. 7B is a diagram showing an example of a circuit configuration of the X-ray detector according to the first embodiment. FIG. 8 is a diagram showing an example of a circuit configuration of the X-ray detector according to the second embodiment. FIG. 9 is a diagram showing an example of a circuit configuration of the X-ray detector according to the second embodiment. FIG. 10 is a diagram showing an example of a circuit configuration of an X-ray detector according to the third embodiment. FIG. 11 is a diagram showing an example of a circuit configuration of an X-ray detector according to the fourth embodiment. FIG. 12 is a diagram showing an example of a circuit configuration of an X-ray detector according to the fifth embodiment. FIG. 13A is a diagram showing an example of a circuit configuration of an X-ray detector according to the sixth embodiment. FIG. 13B is a diagram showing an example of a circuit configuration of the X-ray detector according to the sixth embodiment.

Below, embodiments of the X-ray detector and X-ray CT device will be described with reference to the drawings. Note that the X-ray detector and X-ray CT device according to the present application are not limited to the embodiments shown below. In addition, in the following description, similar components are given common reference numerals, and duplicate descriptions will be omitted.

First Embodiment
In the first embodiment, an X-ray CT device 1 shown in Fig. 1 will be described. Fig. 1 is a block diagram showing an example of the configuration of the X-ray CT device 1 according to the first embodiment. As shown in Fig. 1, the X-ray CT device 1 has a gantry device 10, a bed device 30, and a console device 40.

In FIG. 1, the rotation axis of the rotating frame 13 in a non-tilted state or the longitudinal direction of the top plate 33 of the bed device 30 is the Z-axis direction. The axial direction that is perpendicular to the Z-axis direction and horizontal to the floor surface is the X-axis direction. The axial direction that is perpendicular to the Z-axis direction and perpendicular to the floor surface is the Y-axis direction. For the sake of explanation, FIG. 1 shows the gantry device 10 from multiple directions, and shows a case in which the X-ray CT device 1 has one gantry device 10.

The gantry device 10 has an X-ray tube 11, an X-ray detector 12, a rotating frame 13, an X-ray high voltage device 14, a control device 15, a wedge 16, a collimator 17, and a DAS 18.

The X-ray tube 11 is a vacuum tube that has a cathode (filament) that generates thermoelectrons and an anode (target) that generates X-rays when struck by the thermoelectrons. The X-ray tube 11 generates X-rays to be irradiated onto the subject P by irradiating thermoelectrons from the cathode to the anode when a high voltage is applied from the X-ray high voltage device 14. For example, the X-ray tube 11 may be a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

The X-ray detector 12 has a plurality of detection elements that detect X-rays. Each detection element in the X-ray detector 12 detects X-rays irradiated from the X-ray tube 11 and passing through the subject P, and outputs a signal corresponding to the detected X-ray amount to the DAS 18. The X-ray detector 12 has, for example, a plurality of detection element rows in which a plurality of detection elements are arranged in the channel direction (channel direction, ch direction) along an arc centered on the focus of the X-ray tube 11. The X-ray detector 12 has a structure in which, for example, a plurality of detection element rows in which a plurality of detection elements are arranged in the channel direction are arranged in the row direction (slice direction, row direction).

For example, the X-ray detector 12 is an indirect conversion type detector having a grid, a scintillator array, and an optical sensor array. The scintillator array has multiple scintillators. The scintillator has scintillator crystals that output light with a photon amount corresponding to the amount of incident X-rays. The grid is arranged on the X-ray incident side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid is sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array has a function of converting the amount of light from the scintillator into an electrical signal corresponding to the amount of light, and has an optical sensor such as a photodiode. The X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts the incident X-rays into an electrical signal.

Here, the X-ray detector 12 according to this embodiment has a structure in which modules each having a small number of rows are arranged in the row direction. Also, the X-ray detector 12 has a structure in which modules each having a small number of channels are arranged in the channel direction. FIG. 2 is a diagram showing an example of the X-ray detector 12 according to the first embodiment. Here, FIG. 2 shows an example of an X-ray detector 12 having 4 rows in the channel direction (ch in the figure) and 32 rows in the row direction (row in the figure). For example, as shown in FIG. 2, the X-ray detector 12 has a structure in which modules 120 each having 4 rows in the channel direction and 4 rows in the row direction are arranged in 8 rows in the row direction. Note that FIG. 2 shows a plurality of detection elements 121 in 4 rows in the channel direction and 32 rows in the row direction, but in reality, the X-ray detector 12 has a structure in which a plurality of detection elements 121 shown in FIG. 2 are arranged in a channel direction. That is, the X-ray detector 12 has a structure in which modules 120, each having four rows of detection elements arranged in the channel direction and four rows in the column direction, are arranged in a tiled pattern, with eight rows in the column direction and multiple rows in the channel direction. Note that arranging modules 120 each including multiple detection elements 121 in a tiled pattern is also called tiling.

Returning to FIG. 1, the rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 facing each other and rotates the X-ray tube 11 and the X-ray detector 12 by the control device 15. For example, the rotating frame 13 is a casting made of aluminum. In addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 can also support the X-ray high voltage device 14, the wedge 16, the collimator 17, the DAS 18, etc. Furthermore, the rotating frame 13 can also support various components not shown in FIG. 1. Hereinafter, the rotating frame 13 and the parts of the gantry device 10 that rotate together with the rotating frame 13 are also referred to as the rotating part.

The X-ray high voltage device 14 has electrical circuits such as a transformer and a rectifier, and includes a high voltage generator that generates a high voltage to be applied to the X-ray tube 11, and an X-ray control device that controls the output voltage according to the X-rays generated by the X-ray tube 11. The high voltage generator may be of a transformer type or an inverter type. The X-ray high voltage device 14 may be provided on the rotating frame 13, or on a fixed frame (not shown).

The control device 15 has a processing circuit having a CPU (Central Processing Unit) and the like, and a driving mechanism such as a motor and an actuator. The control device 15 receives an input signal from the input interface 43 and controls the operation of the gantry 10 and the bed 30. For example, the control device 15 controls the rotation of the rotating frame 13, the tilt of the gantry 10, and the operation of the bed 30 and the tabletop 33. As an example, the control device 15 rotates the rotating frame 13 around an axis parallel to the X-axis direction based on input inclination angle (tilt angle) information to control the tilt of the gantry 10. The control device 15 may be provided in the gantry 10 or in the console device 40.

The wedge 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. For example, the wedge 16 is a wedge filter or bow-tie filter, which is a filter made of aluminum or the like processed to have a predetermined target angle and a predetermined thickness.

The collimator 17 is a lead plate or the like for narrowing the irradiation range of the X-rays that have passed through the wedge 16, and a slit is formed by combining multiple lead plates or the like. The collimator 17 is sometimes called an X-ray aperture. Also, while FIG. 1 shows a case in which the wedge 16 is placed between the X-ray tube 11 and the collimator 17, the collimator 17 may also be placed between the X-ray tube 11 and the wedge 16. In this case, the wedge 16 transmits and attenuates the X-rays that are irradiated from the X-ray tube 11 and whose irradiation range is limited by the collimator 17.

DAS18 collects X-ray signals detected by each detection element of X-ray detector 12. For example, DAS18 has an amplifier that performs an amplification process on the electrical signal output from each detection element, and an A/D converter (ADC: Analog-to-Digital converter) that converts the electrical signal into a digital signal, and generates detection data. DAS18 is realized, for example, by a processor.

Here, the DAS 18 sequentially collects X-ray signals for each detection element group in the X-ray detector 12. In other words, the DAS 18 is a sequential collection type DAS. For example, the DAS 18 is connected to each detection element in the detection element group via a switch, and sequentially reads out the charge integrated in each detection element while switching the detection element to be connected.

The data generated by the DAS 18 is transmitted by optical communication from a transmitter having a light emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on a non-rotating part of the gantry 10 (e.g., a fixed frame, etc. (not shown in FIG. 1)), and then transferred to the console device 40. Here, the non-rotating part is, for example, a fixed frame that rotatably supports the rotating frame 13. Note that the method of transmitting data from the rotating frame 13 to the non-rotating part of the gantry 10 is not limited to optical communication, and any non-contact data transmission method or a contact data transmission method may be adopted.

The bed device 30 is a device on which the subject P to be imaged is placed and moved, and includes a base 31, a bed driving device 32, a top plate 33, and a support frame 34. The base 31 is a housing that supports the support frame 34 so that it can move in the vertical direction. The bed driving device 32 is a drive mechanism that moves the top plate 33 on which the subject P is placed in the longitudinal direction of the top plate 33, and includes a motor, an actuator, etc. The top plate 33, which is provided on the upper surface of the support frame 34, is a plate on which the subject P is placed. Note that the bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33 in addition to the top plate 33.

The console device 40 has a memory 41, a display 42, an input interface 43, and a processing circuit 44. Note that although the console device 40 is described as being separate from the gantry device 10, the gantry device 10 may include the console device 40 or some of the components of the console device 40.

The memory 41 is realized, for example, by a semiconductor memory element such as a RAM (Random Access Memory), a flash memory, a hard disk, an optical disk, etc. The memory 41 stores, for example, projection data and reconstructed image data. Also, for example, the memory 41 stores a program for enabling the circuitry included in the X-ray CT device 1 to realize its functions. Note that the memory 41 may also be realized by a group of servers (cloud) connected to the X-ray CT device 1 via a network.

The display 42 displays various types of information. For example, the display 42 displays various images generated by the processing circuit 44, or displays a GUI (Graphical User Interface) for receiving various operations from the operator. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 42 may be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 40 main body.

The input interface 43 accepts various input operations from the operator, converts the accepted input operations into electrical signals, and outputs the electrical signals to the processing circuit 44. For example, the input interface 43 accepts input operations of collection conditions (imaging conditions) when collecting projection data from the operator. The imaging conditions will be described later. In addition, for example, the input interface 43 accepts input operations of reconstruction conditions when reconstructing CT image data, image processing conditions when generating post-processed images from CT image data, and the like from the operator.

For example, the input interface 43 is realized by a mouse, keyboard, trackball, switch, button, joystick, a touchpad that performs input operations by touching the operation surface, a touch screen in which a display screen and a touchpad are integrated, a non-contact input circuit using an optical sensor, a voice input circuit, etc. The input interface 43 may be provided in the pedestal device 10. The input interface 43 may also be configured as a tablet terminal or the like that can wirelessly communicate with the console device 40 main body. The input interface 43 is not limited to only those that have physical operation parts such as a mouse and keyboard. For example, an example of the input interface 43 includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the console device 40 and outputs the electrical signal to the processing circuit 44.

The processing circuitry 44 controls the operation of the entire X-ray CT device 1. Note that the processing circuitry 44 is not limited to being included in the console device 40. For example, the processing circuitry 44 may be included in an integrated server that collectively processes detection data acquired by multiple medical image diagnostic devices. For example, the processing circuitry 44 executes a system control function 441, a pre-processing function 442, a generation function 443, and an output function 444.

The system control function 441 controls various processes in the X-ray CT device 1 based on input operations received from the operator via the input interface 43. For example, the system control function 441 controls the bed drive device 32, collimator 17, control device 15, X-ray high voltage device 14, etc. in the X-ray CT device 1 to perform positioning scans and main scans.

The pre-processing function 442 generates projection data by performing correction processes such as logarithmic conversion, offset correction, sensitivity correction, and beam hardening correction on the detection data transmitted from the DAS 18. The pre-processing function 442 then stores the generated projection data in the memory 41. Note that the data before pre-processing (detection data) and the data after pre-processing may be collectively referred to as projection data.

The generation function 443 generates various images from the projection data stored by the memory 41, and stores the generated images in the memory 41. For example, the generation function 443 reconstructs CT image data by reconstructing the projection data using various reconstruction methods (e.g., back projection methods such as FBP (Filtered Back Projection) and successive approximation methods, etc.), and stores the reconstructed CT image data in the memory 41. The generation function 443 also generates CT images such as MPR images from the CT image data by performing various image processing, and stores the generated CT images in the memory 41.

The output function 444 outputs CT images, CT image data, etc. For example, the output function 444 displays the CT image on the display 42. Also, for example, the output function 444 outputs the CT image data to an external device (for example, a server device that stores image data, etc.) connected to the X-ray CT device 1 via a network.

In the X-ray CT apparatus 1 shown in FIG. 1, each processing function is stored in the memory 41 in the form of a program executable by a computer. The processing circuitry 44 is a processor that realizes the function corresponding to each program by reading the program from the memory 41 and executing it. In other words, when each program has been read, the processing circuitry 44 has the function corresponding to the read program.

Note that, although FIG. 1 shows a case where each of the processing functions of the system control function 441, the preprocessing function 442, the generation function 443, and the output function 444 is realized by a single processing circuit 44, the embodiment is not limited to this. For example, the processing circuit 44 may be configured by combining multiple independent processors, and each processor may realize each processing function by executing each program. Furthermore, each processing function possessed by the processing circuit 44 may be realized by being appropriately distributed or integrated into a single or multiple processing circuits.

The overall configuration of the X-ray CT device 1 according to this embodiment has been described above. With this configuration, the X-ray CT device 1 according to this embodiment makes it possible to properly perform sequential acquisition in an X-ray detector using modules composed of multiple detection elements. Specifically, the X-ray CT device 1 makes it possible to properly perform sequential acquisition in an X-ray detector in which modules composed of multiple detection elements are arranged in at least one of the row direction and the channel direction. More specifically, it makes it possible to properly perform sequential acquisition by adjusting the readout timing between each module according to the readout timing of each detection element.

First, the sequential acquisition method will be described. For example, in the sequential acquisition method, an ADC is arranged for each detection element group consisting of multiple detection elements (e.g., 32 in FIG. 2) arranged along the column direction of the X-ray detector 12. In other words, the ADCs are arranged for the number of channels. Then, the DAS 18 is connected to each detection element group via a switch, and sequentially collects X-ray signals detected by the detection element groups while the X-ray tube 11 is generating X-rays.

For example, when DAS18 turns on the connection with a first detection element in the detection element group, the charge integrated in the first detection element is read out as an X-ray signal. Next, DAS18 turns off the connection with the first detection element and turns on the connection with a second detection element adjacent to the first detection element, so that the charge integrated in the second detection element is read out as an X-ray signal. Note that when the connection with DAS18 is turned off, each detection element starts integrating charge. Similarly, DAS18 controls each detection element in the detection element group so that the charge integrated in each detection element is sequentially read out as an X-ray signal.

DAS18 executes the above-mentioned control for each view to collect detection data for each view. That is, DAS18 sequentially collects signals from the detection element group for the number of elements in one view. Similarly, DAS18 sequentially collects signals for the number of elements in the next view.

As described above, in the sequential acquisition method, sequential acquisition is performed from multiple detection elements along the column direction. However, when multiple detection elements are tiled as in the X-ray detector 12 of this embodiment, a gap may occur in the readout timing between two adjacent detection elements between modules, resulting in artifacts.

The following describes an example of the sequential acquisition described above in the tiled X-ray detector 12 shown in FIG. 2. For example, when sequential acquisition is performed in the column direction in the X-ray detector 12 shown in FIG. 2, an ADC is provided for each module 120, and sequential acquisition is performed in the column direction for each module.

As an example, in each module 120 in FIG. 2, if sequential collection is performed from the rightmost detector element 121 to the leftmost detector element 121 when the column direction is horizontal, a large difference will occur in the readout timing of adjacent detector elements 121 in adjacent modules 120. For example, the rightmost detector element 121 in the leftmost module 120 in FIG. 2 is read out at the start of sequential collection, but the leftmost detector element 121 in the second module 120 from the left in FIG. 2 is read out at the third collection from the start of sequential collection.

In other words, when sequential collection is started simultaneously in each module 120, the readout timing of the rightmost detection element 121 is the first, and the readout timing of the leftmost detection element 121 is the last of the four detection elements in the column direction of the module 120. Therefore, even though the rightmost detection element 121 and the leftmost detection element 121 are adjacent to each other, a large difference in readout timing occurs, and artifacts may occur. Note that the difference in readout timing of sequential collection among multiple detection elements 121 included in the same module 120 is not large, so no visible artifacts occur.

As described above, in an X-ray detector 12 in which modules made up of multiple detection elements are arranged in a column direction, there is a risk of artifacts occurring when performing normal sequential collection. Therefore, in the X-ray CT device 1 according to the first embodiment, the readout timing between each module is adjusted according to the readout timing of each detection element, making it possible to perform sequential collection appropriately.

Figure 3 is a diagram showing an example of the circuit configuration of the X-ray detector 12 according to the first embodiment. Note that while Figure 3 shows the circuit configuration of three modules 120 arranged in a column direction, in reality, as shown in Figure 2, eight modules 120 are arranged in a column direction.

For example, as shown in FIG. 3, the X-ray detector 12 has a plurality of modules 120, an ADC 123a, an ADC 123b, and a control circuit 124. Here, the module 120 is an example of a detection array. Also, the ADC 123a and the ADC 123b are an example of a processing unit. Also, the control circuit 124 is an example of a control unit.

The multiple modules 120 each include multiple detection elements 121. For example, the multiple modules 120 each include four detection elements 1211 and four detection elements 1212. Here, the detection elements 1211 and detection elements 1212 shown in the module 120 in FIG. 3 each indicate four detection elements arranged in a column direction. That is, in FIG. 3, the four detection elements 1211 and the four detection elements 1212 are arranged in a row, but in reality, the four detection elements 1211 and the four detection elements 1212 are arranged in the channel direction.

For example, the four detection elements 1211 correspond to the four detection elements in the top channel when the column direction is horizontal in the module of FIG. 2. The four detection elements 1212 correspond to the four detection elements in the second channel from the top when the column direction is horizontal in the module of FIG. 2.

The detection element 1211 is connected to the switch 122 and the ADC 123b. The detection element 1211 outputs an electrical signal to the ADC 123b in response to a start pulse signal (SP signal) input from the control circuit 124 to the switch 122. The detection element 1212 is connected to the switch 122 and the ADC 123a. The detection element 1212 outputs an electrical signal to the ADC 123a in response to the SP signal input from the control circuit 124 to the switch 122. Note that while FIG. 3 shows that each module 120 includes two rows of detection element groups in the channel direction, in reality, it includes two more rows of detection element groups in the channel direction, and each detection element group is connected to a switch and an ADC. The same control as described below is executed for each detection element group.

The switch 122 is, for example, a shift register, and is arranged in each module 120. It receives an SP signal from the control circuit 124 and switches the connection with each detection element on and off. Here, the modules 120 according to this embodiment each have a port for receiving the SP signal from the control circuit 124. That is, each module 120 receives the SP signal independently from the control circuit 124.

ADC123a receives electrical signals sequentially output from the detection elements 1212 included in each module 120 and converts them into digital signals. ADC123b converts electrical signals sequentially output from the detection elements 1211 included in each module 120 into digital signals. Although not shown, an amplifier that amplifies the electrical signals output from the detection elements is arranged in front of ADC123a and ADC123b. ADC123a and ADC123b may be arranged on a board provided in the rear of the detection elements 121, or may be arranged in DAS18.

The control circuit 124 controls the readout timing of the detection elements between the multiple modules 120 to be changed. Specifically, the control circuit 124 is disposed on a substrate provided after the detection elements 121 or on the DAS 18, and adds a delay to the readout timing of the detection elements between the multiple modules 120. More specifically, the control circuit 124 adjusts the readout timing for each module by transmitting a unique SP signal to each module. For example, the control circuit 124 sequentially collects electrical signals for the four detection elements 1211 and the four detection elements 1212 by transmitting an SP signal "A" to the switch 122 of the upper module 120 in FIG. 3. Here, for example, the switch 122 switches the connection every clock by transmitting an SP signal every clock in the direction of the arrow between the switches 122, thereby performing sequential collection with the readout timing shifted by one clock.

Similarly, the control circuit 124 sequentially collects electrical signals from the four detection elements 1211 and the four detection elements 1212 in the middle module 120 by sending an SP signal "B" to the switch 122 of the middle module 120 in FIG. 3. Here, the SP signal "B" is a signal controlled so that reading in the middle module 120 starts at a timing shifted by one clock from the last reading based on the SP signal "A". As a result, in the middle module 120, reading of the detection elements 1211 and 1212 adjacent to the detection elements 1211 and 1212 of the upper module 120 starts one clock after reading in the upper module 120 ends.

Similarly, the control circuit 124 sequentially collects electrical signals from the four detection elements 1211 and the four detection elements 1212 in the lower module 120 by sending an SP signal "C" to the switch 122 of the lower module 120 in FIG. 3. Here, the SP signal "C" is a signal controlled so that the readout in the lower module 120 starts at a timing shifted by one clock from the last readout based on the SP signal "B". As a result, in the lower module 120, the readout of the detection elements 1211 and 1212 adjacent to the detection elements 1211 and 1212 of the middle module 120 starts one clock after the readout in the middle module 120 ends.

As described above, the X-ray detector 12 according to the first embodiment eliminates gaps in the readout timing between modules by controlling the readout timing for each module using an SP signal, enabling proper sequential collection.

Here, the control circuit 124 adds a delay according to the read order between the multiple modules and the read order between the multiple detection elements contained in the multiple modules. In other words, by controlling the read timing for each module with the SP signal, it is possible to collect data sequentially in various read orders when gaps in the read timing between modules are eliminated.

Below, variations in the readout order will be described with reference to Figs. 4A to 7B. Figs. 4A, 5A, 6A, and 7A are diagrams showing an example of the readout order according to the first embodiment. Figs. 4B, 5B, 6B, and 7B are diagrams showing an example of the circuit configuration of the X-ray detector according to the first embodiment. Here, Fig. 4B shows a circuit configuration for realizing the readout order shown in Fig. 4A. Fig. 5B shows a circuit configuration for realizing the readout order shown in Fig. 5A. Fig. 6B shows a circuit configuration for realizing the readout order shown in Fig. 6A. Fig. 7B shows a circuit configuration for realizing the readout order shown in Fig. 7A. Figs. 4B, 5B, 6B, and 7B show a part of the X-ray detector 12, similar to Fig. 3.

For example, in the X-ray detector 12 according to the first embodiment, as shown in FIG. 4A, adjacent modules 120 can perform readout in opposite directions. Here, in FIG. 4A, when the column direction is horizontal, arrows at the same height indicate that readout starts at the same timing. That is, in FIG. 4A, because all the arrows are at the same height, it indicates that in each module 120, readout starts at the start point simultaneously in the readout order from the start point to the end point of the arrow.

In the case of the readout order shown in FIG. 4A, the X-ray detector 12 has, for example, a circuit configuration shown in FIG. 4B. Here, FIG. 4B shows the circuit configuration of the three modules from the left end when the column direction in the X-ray detector 12 in FIG. 4A is horizontal. That is, the bottom end of the module 120 in FIG. 4A corresponds to the bottom end of the module 120 in FIG. 4B. For example, as shown in FIG. 4B, the X-ray detector 12 has a different input direction of the SP signal in the upper module 120 and the lower module 120 from that in FIG. 3. That is, in the X-ray detector 12 shown in FIG. 4B, the SP signal "A" and the SP signal "C" are input to the switch 122 so that readout starts from the detection element on the readout start side indicated by the start point of the arrow in FIG. 4A.

Here, the control circuit 124 shown in FIG. 4B transmits SP signals "A," "B," and "C" that cause all modules 120 to start reading simultaneously. That is, in the read order shown in FIG. 4A, adjacent modules 120 read in opposite directions, so there is no large gap in read timing at the module boundaries.

Also, for example, in the X-ray detector 12 according to the first embodiment, as shown in FIG. 5A, in each module 120, readout can be performed from the detection element corresponding to the center outward. Here, in FIG. 5A, all the bidirectional arrows are at the same height, which indicates that in each module 120, readout of the center starts simultaneously in the readout order from the center of the bidirectional arrow to the outside.

In the case of the readout order shown in FIG. 5A, the X-ray detector 12 has, for example, the circuit configuration shown in FIG. 5B. Here, FIG. 5B shows the circuit configuration of the three modules from the left end when the column direction in the X-ray detector 12 in FIG. 5A is horizontal. That is, the bottom end of the module 120 in FIG. 5A corresponds to the bottom end of the module 120 in FIG. 5B. For example, the X-ray detector 12 differs from FIG. 3 in that, as shown in FIG. 5B, the SP signal is input from the center to both the left and right sides in each module 120. That is, in the X-ray detector 12 shown in FIG. 5B, the SP signals "A", "B", and "C" are input to the switch 122 so that readout starts from the detection element corresponding to the readout start position shown at the center of the double-headed arrow in FIG. 5A.

Here, in the X-ray detector 12 shown in FIG. 5B, when reading out from the detection element corresponding to the readout start position toward both the left and right sides in each module 120, the readout order of the left and right detection elements is controlled so as not to overlap. For example, the X-ray detector 12 controls so that a Clock signal is input alternately from the center of the four detection elements 1211 to the left and right detection elements 1211, thereby reading out the electrical signals of the detection elements 1211 alternately from the left to the right.

The control circuit 124 shown in FIG. 5B also transmits SP signals "A," "B," and "C" that cause all modules 120 to start reading simultaneously. That is, in the read order shown in FIG. 5A, reading is performed from the detection element corresponding to the center toward the outside, so that no large gaps in read timing occur at the module boundaries.

For example, in the X-ray detector 12 according to the first embodiment, as shown in FIG. 6A, a combination of readouts in different directions and readouts in the same direction can be performed between adjacent modules 120. For example, as shown in FIG. 6A, in an X-ray detector in which eight modules are arranged in a column direction, a readout order can be realized in which the readout direction is reversed for every two adjacent modules 120.

Here, in FIG. 6A, arrows at different heights indicate that readout start timing is different. Also, in FIG. 6A, arrows at the same height indicate that readout start timing is the same. For example, in FIG. 6A, adjacent modules with arrows that have the same direction have different heights, so readout starts at different times at the start points of the arrows. That is, readout starts from the start point of the arrow at a higher position, and after readout at the end point of the arrow at a higher position, readout starts at the start point of the arrow at a lower position. Also, for example, adjacent modules with arrows that have different direction have the same heights, so readout starts at the start points of the arrows at the same timing.

In the case of the readout order shown in FIG. 6A, the X-ray detector 12 has, for example, the circuit configuration shown in FIG. 6B. Here, FIG. 6B shows the circuit configuration of the three modules from the left end when the column direction in the X-ray detector 12 in FIG. 6A is horizontal. That is, the bottom end of the module 120 in FIG. 6A corresponds to the bottom end of the module 120 in FIG. 6B. For example, as shown in FIG. 6B, the X-ray detector 12 has an input direction of the SP signal in the upper module 120 that is different from that in FIG. 3. That is, in the X-ray detector 12 shown in FIG. 6B, the SP signal "A" is input to the switch 122 so that readout starts from the detection element on the readout start side indicated by the start point of the arrow in FIG. 6A.

The control circuit 124 shown in FIG. 6B transmits SP signals between adjacent modules 120, which start reading in different directions, to the modules 120 at the same time. For example, the control circuit 124 transmits SP signals "A" and "B" to the upper and middle modules 120, which start reading at the same time. On the other hand, the control circuit 124 transmits SP signals between adjacent modules 120, which start reading in the same direction, to the modules 120 at the lower level, which start reading at different timings. For example, the control circuit 124 transmits SP signal "C" to the lower module 120, so that reading starts at a timing shifted by one clock after reading ends in the middle module 120.

In other words, in the read order shown in FIG. 6A, when reading in opposite directions between adjacent modules 120, reading starts at the same timing, and when reading in the same direction, a delay is added to the read timing, so that no large gaps in read timing occur at module boundaries.

When performing a readout that combines readouts in different directions and readouts in the same direction between adjacent modules 120, for example, the X-ray detector 12 according to the first embodiment can perform the readout shown in FIG. 7A. For example, as shown in FIG. 7A, in an X-ray detector in which eight modules are arranged in the column direction, a readout order can be realized in which the readout direction is reversed at the boundary between module groups including four consecutive modules 120.

Here, in FIG. 7A, arrows at different heights indicate that readout start timing is different. Also, in FIG. 7A, arrows at the same height indicate that readout start timing is the same. For example, in FIG. 7A, between modules with arrows pointing in the same direction, the heights of the arrows are different, so readout starts at different times at the start points of the arrows. That is, readout starts from the start point of the arrow at a higher position, and after readout at the end point of the arrow at a higher position, readout starts at the start point of the arrow at a lower position. Also, for example, in FIG. 7A, between modules with arrows at the same height, readout starts at the start points of the arrows at the same timing.

In the case of the readout order shown in FIG. 7A, the X-ray detector 12 has, for example, the circuit configuration shown in FIG. 7B. Here, FIG. 7B shows the circuit configuration of the three modules from the left end when the column direction in the X-ray detector 12 of FIG. 7A is the horizontal direction. In other words, the bottom end of the module 120 in FIG. 7A corresponds to the bottom end of the module 120 in FIG. 7B. For example, the X-ray detector 12 can achieve the readout order shown in FIG. 7A with the same circuit configuration as in FIG. 3, as shown in FIG. 7B.

In other words, in the case of the read order shown in Figure 7A, a delay is added to the timing of the start of read between modules that read in the same direction, and the read timing is made the same between adjacent modules that read in different directions. This prevents large gaps in read timing at module boundaries.

As described above, according to the first embodiment, the multiple modules 120 include multiple detection elements 121. The control circuit 124 adds a delay to the readout timing of the detection elements 121 between the multiple modules 120. The ADC processes signals from the multiple detection elements 121. Therefore, the X-ray CT device 1 according to the first embodiment prevents a large deviation in the readout timing at the boundary between the modules 120, and enables sequential acquisition to be performed appropriately in the X-ray detector 12 in which the modules 120 composed of multiple detection elements 121 are arranged in a column direction. As a result, the X-ray CT device 1 can configure the X-ray detector 12 by tiling without impairing the performance of sequential acquisition, enabling the detector to be made low cost and have a wide coverage.

Second Embodiment
In the above-described first embodiment, a case has been described in which the readout start timing is adjusted for each module 120. In the second embodiment, a case will be described in which sequential acquisition is appropriately performed by connecting the modules 120 with a control line that controls the readout timing. That is, a case will be described in which the modules 120 are daisy-chain connected in the X-ray detector 12 according to the second embodiment.

Figure 8 is a diagram showing an example of the circuit configuration of the X-ray detector 12 according to the second embodiment. Note that while Figure 3 shows the circuit configuration of three modules 120 arranged in a column direction, in reality, as shown in Figure 2, eight modules 120 are arranged in a column direction.

As shown in FIG. 8, the X-ray detector 12 according to the second embodiment has a plurality of modules 120, an ADC 123a, an ADC 123b, a control circuit 124a, and a control line 125. Here, the control line 125 is an example of a control line. Hereinafter, parts having the same configuration as those described in the first embodiment are given the same reference numerals as in FIG. 3, and the description thereof will be omitted.

The control line 125 is provided, for example, on a substrate provided after the detection element 121, connects the multiple modules 120, and associates the readout timing of the multiple detection elements 121 included in each of the multiple modules 120. For example, as shown in FIG. 8, the control line 125 connects the switches 122 in each module 120, and transmits the SP signal between the modules 120.

The control circuit 124a is placed on a board provided after the detection element 121 or on the DAS 18, and controls the readout timing of the X-ray detector 12 by sending an SP signal to the switch 122.

In the X-ray detector 12 shown in FIG. 8, the control circuit 124a controls the four detection elements 1211 and the four detection elements 1212 to sequentially collect electrical signals by transmitting an SP signal to the switch 122 of the upper module 120 in FIG. 8. Here, for example, the switch 122 transmits an SP signal every clock in the direction of the arrow between the switches 122, thereby switching the connection every clock and executing sequential collection with the readout timing shifted by one clock.

Then, the switch 122 of the upper module 120 transmits an SP signal to the switch 122 of the middle module 120 at a timing of 1 Clock via the control line 125. As a result, in the detection element 1211 and the detection element 1212 of the middle module 120, sequential collection is performed with the readout timing shifted by 1 Clock from the upper module 120.

Similarly, between the middle module 120 and the lower module 120, the SP signal is transmitted via the control line 125, which prevents the readout timing difference between the modules 120 from becoming too large. With the X-ray detector configuration in FIG. 8, for example, the readout order shown in FIG. 7A can be realized.

The readout order of FIG. 6A can also be achieved by using a daisy chain connection between the modules 120. FIG. 9 is a diagram showing an example of the circuit configuration of the X-ray detector 12 according to the second embodiment. For example, in the X-ray detector 12 when realizing the readout order of FIG. 6A, as shown in FIG. 9, an SP signal is input to each of the upper module 120 and the middle module 120.

Then, sequential readout is performed between the middle module 120 and the lower module 120 via the control line 125. Also, sequential readout is performed between the upper module 120 and the module 120 further above (not shown) via the control line 125.

As described above, according to the second embodiment, the multiple modules 120 include multiple detection elements 121. The control line 125 connects the multiple modules 120 and associates the readout timing of the multiple detection elements 121 included in each of the multiple modules 120. The ADC processes signals from the multiple detection elements 121. Therefore, the X-ray CT device 1 according to the second embodiment prevents a large deviation in readout timing from occurring at the boundaries of the modules 120 without performing readout control for each module 120 using the SP signal, and enables appropriate sequential collection in the X-ray detector 12 in which modules 120 composed of multiple detection elements 121 are arranged in a column direction.

Third Embodiment
The above-described embodiments have described a case in which the read start timing is adjusted for each module 120, and a case in which the modules 120 are daisy-chained. In the third embodiment, a case in which the read start timing is adjusted for each module 120 and the modules 120 are daisy-chained will be described.

Figure 10 is a diagram showing an example of the circuit configuration of an X-ray detector 12 according to the third embodiment. Note that while Figure 10 shows the circuit configuration of four modules 120 arranged in a column direction, in reality, as shown in Figure 2, eight modules 120 are arranged in a column direction.

As shown in FIG. 10, the X-ray detector 12 according to the third embodiment has a plurality of modules 120, an ADC 123a, an ADC 123b, a control circuit 124, and a control line 125. Hereinafter, the same reference numerals as in FIG. 3 and FIG. 8 are used for the components having the same configuration as those described in the first and second embodiments, and the description thereof will be omitted.

For example, in the X-ray detector 12 according to the third embodiment, as shown in FIG. 10, the upper module 120 and the second module 120 from the top are connected by a control line 125, and the third module 120 and the lower module 120 are connected by a control line 125.

Then, the control circuit 124 adds a delay to the read timing of the detection elements 121 between the multiple module groups for the module groups connected by the control lines 125. For example, the control circuit 124 adds a delay to the read timing between the module groups connected by the control lines 125 by sending an SP signal "A" to the upper module 120 and an SP signal "B" to the module 120 in the third row from the top.

As an example, the control circuit 124 transmits an SP signal "B" to the third module 120 from the top, which is controlled so that reading in the third module 120 from the top is started at a timing shifted by one clock from the last reading based on the SP signal "A". This allows electrical signals to be collected seamlessly and sequentially from the detection elements 1211 and 1212 in the upper module 120 to the detection elements 1211 and 1212 in the lower module 120. Note that with the configuration of the X-ray detector 12 in FIG. 10, for example, the read order shown in FIG. 7A can be realized.

As described above, according to the third embodiment, the control line 125 connects the multiple modules 120 and associates the readout timing of the multiple detection elements 121 included in each of the multiple modules 120. The control circuit 124 adds a delay to the readout timing of the detection elements 121 between the multiple module 120 groups for the module 120 groups connected by the control line 125. Therefore, the X-ray CT device 1 according to the third embodiment prevents a large deviation in the readout timing at the boundaries of the modules 120, and enables appropriate sequential collection in the X-ray detector 12 in which modules 120 composed of multiple detection elements 121 are arranged in a column direction.

(Fourth embodiment)
In the above-described embodiment, a case where the readout timing is adjusted between modules 120 in the column direction is described. In the fourth embodiment, a case where the readout timing is adjusted between modules in the channel direction is described. That is, in the fourth embodiment, an ADC is arranged for each detection element group consisting of a plurality of detection elements arranged along the channel direction. In other words, the ADCs are arranged for the number of columns. Then, the DAS 18 is connected to each of the detection element groups via a switch, and sequentially collects X-ray signals detected by the detection element groups while the X-ray tube 11 is generating X-rays.

Figure 11 is a diagram showing an example of the circuit configuration of the X-ray detector 12 according to the fourth embodiment. Note that while Figure 11 shows the circuit configuration of two modules 120 lined up in the channel direction, in reality, eight modules 120 are further lined up in each row direction. That is, the X-ray detector 12 according to the fourth embodiment has two rows of modules 120 arranged in the channel direction and eight rows in the row direction. Note that the number of modules 120 lined up in the channel direction is not limited to two, and three or more modules 120 may be lined up in the channel direction.

As shown in FIG. 11, the X-ray detector 12 according to the fourth embodiment has a plurality of modules 120, an ADC 123a, an ADC 123b, and a control circuit 124. Hereinafter, the same reference numerals as in FIG. 3 and FIG. 8 are used for components having the same configuration as those described in the above-mentioned embodiments, and the description thereof will be omitted.

The multiple modules 120 each include multiple detection elements 121. For example, the multiple modules 120 each include detection elements 1211 to 1214. Here, the detection elements 1211 to 1214 shown in the module 120 in FIG. 11 each represent four detection elements arranged in the channel direction. That is, in FIG. 11, the four detection elements 1211 to 1214 and the four detection elements 1211 to 1214 are lined up in a row, but in reality, the four detection elements 1211 to 1214 and the four detection elements 1211 to 1214 are arranged in the row direction.

For example, detection element 1211 corresponds to the detection element in the topmost channel when the column direction is horizontal in the module of FIG. 2. Detection element 1212 corresponds to the detection element in the second channel from the top when the column direction is horizontal in the module of FIG. 2. Detection element 1213 corresponds to the detection element in the third channel from the top when the column direction is horizontal in the module of FIG. 2. Detection element 1214 corresponds to the detection element in the fourth channel from the top when the column direction is horizontal in the module of FIG. 2.

The detection element groups 1211-1214 in each column are connected to the switch 122 and ADC 123b, or the switch 122 and ADC 123a. The detection element groups 1211-1214 in each column output an electrical signal to the ADC 123a or ADC 123b in response to a start pulse signal (SP signal) input from the control circuit 124 to the switch 122. Note that while FIG. 11 shows that each module 120 includes two columns of detection element groups in the column direction, in reality, it includes two more columns of detection element groups in the column direction, and each detection element group is connected to a switch and an ADC. The same control as described below is executed for each detection element group.

The control circuit 124 adjusts the readout timing for each module by sending a unique SP signal to each module. For example, the control circuit 124 sequentially collects electrical signals from the detection element groups 1211 to 1214 by sending an SP signal "A" to the switch 122 of the module 120 on the left side in FIG. 11. Here, for example, the switch 122 sends an SP signal every clock in the direction of the arrow between the switches 122, thereby switching the connection every clock and executing sequential collection with the readout timing shifted by one clock.

Similarly, the control circuit 124 sequentially collects electrical signals from the detection element groups 1211-1214 in the right-side module 120 by sending an SP signal "B" to the switch 122 of the right-side module 120 in FIG. 11. Here, the SP signal "B" is a signal controlled so that readout in the right-side module 120 begins one clock after the last readout based on the SP signal "A". As a result, readout of the detection element 1211 in the right-side module 120 begins one clock after readout of the detection element 1214 in the left-side module 120 has ended.

As described above, the X-ray detector 12 according to the fourth embodiment eliminates gaps in the readout timing between modules by controlling the readout timing for each module using an SP signal, enabling proper sequential collection.

In the above embodiment, an example has been described in which the read start timing is adjusted between modules 120 arranged in the channel direction. However, the adjustment of the read timing in the channel direction can also be achieved by a daisy chain connection. In such a case, the modules 120 arranged in the channel direction are connected by a control line. For example, by making a connection in the channel direction similar to the daisy chain connection in the column direction shown in FIG. 8, it is possible to adjust the read timing in the channel direction.

In addition, the adjustment of the read timing in the channel direction can also be achieved by daisy-chaining the modules 120 while adjusting the read start timing for each module 120. For example, by performing the same connection and control in the channel direction as the column-wise connection and control shown in FIG. 10, it is possible to adjust the read timing in the channel direction.

As described above, according to the fourth embodiment, the multiple modules 120 are arranged in the channel direction. The control circuit 124 controls the readout timing of the detection elements 121 between the multiple modules 120 arranged in the channel direction to change. Therefore, the X-ray CT device 1 according to the fourth embodiment prevents a large deviation in the readout timing at the boundaries of the modules 120, and enables appropriate sequential collection in the X-ray detector 12 in which modules 120 composed of multiple detection elements 121 are arranged in the channel direction.

Fifth Embodiment
In the above-described embodiment, the case where the read timing is adjusted between the modules 120 in the column direction or the channel direction has been described. In the fifth embodiment, the case where the read timing is adjusted between the modules in the column direction and the channel direction will be described.

Figure 12 is a diagram showing an example of the circuit configuration of an X-ray detector 12 according to the fifth embodiment. Note that while Figure 12 shows a circuit configuration in which three modules 120 are arranged in the column direction and two in the channel direction, in reality, eight modules 120 are arranged in the column direction. Also, three or more modules 120 may be arranged in the channel direction.

As shown in FIG. 12, the X-ray detector 12 according to the fifth embodiment has modules 120a-120f, ADCs 123a-123d, a control circuit 124a, and a control line 125. Hereinafter, parts having the same configuration as those described in the above-mentioned embodiments are given the same reference numerals as in FIG. 3 and FIG. 8, and the description thereof will be omitted.

The ADC 123a receives electrical signals sequentially output from the detection elements 1212 included in the modules 120a, 120c, and 120e, and converts them into digital signals. The ADC 123b receives electrical signals sequentially output from the detection elements 1211 included in the modules 120a, 120c, and 120e, and converts them into digital signals. The ADC 123c receives electrical signals sequentially output from the detection elements 1212 included in the modules 120b, 120d, and 120f, and converts them into digital signals. The ADC 123d receives electrical signals sequentially output from the detection elements 1211 included in the modules 120b, 120d, and 120f, and converts them into digital signals.

In the X-ray detector 12 shown in FIG. 12, the control circuit 124a transmits an SP signal to the switch 122 of the module 120a, thereby controlling the sequential collection of electrical signals from the four detection elements 1211 and the four detection elements 1212 in the module 120a. Here, for example, the switch 122 transmits an SP signal every clock in the direction of the arrow between the switches 122, thereby switching the connection every clock and executing sequential collection with the readout timing shifted by one clock.

Then, the switch 122 of the module 120a transmits an SP signal to the switch 122 of the module 120b at a timing of 1 Clock via the control line 125. As a result, in the detection element 1211 and the detection element 1212 of the module 120b, sequential collection is performed with the readout timing shifted by 4 Clocks from the module 120a.

Furthermore, the switch 122 of the module 120b transmits an SP signal to the switch 122 of the module 120c at a timing of 1 Clock via the control line 125. As a result, in the detection element 1211 and the detection element 1212 of the module 120c, sequential collection is performed with the readout timing shifted by 4 Clocks from the module 120a.

Then, a similar SP signal is transmitted in the order of module 120d, module 120e, and module 120f. This allows sequential collection to be performed between modules in the column direction and between modules in the channel direction, with the readout timing shifted by 4 clocks.

In the above embodiment, the read timing adjustment between modules in the column direction and channel direction is achieved by daisy chain connection. However, the read timing adjustment between modules in the column direction and channel direction can also be achieved by adjusting the read start timing between modules 120. In such a case, for example, as in FIG. 3, modules 120a to 120f are each connected to a control circuit 124, and a timing-adjusted SP signal is sent to the switch 122 of each module, making it possible to adjust the read timing between modules in the column direction and channel direction.

Also, adjustment of the read timing between modules in the column direction and channel direction can be realized by daisy-chaining the modules 120 while adjusting the read start timing for each module 120. For example, modules 120a, 120c, and 120e are daisy-chained as in FIG. 8. Furthermore, modules 120b, 120c, and 120e are daisy-chained as in FIG. 8. Then, the control circuit 124 transmits an SP signal to the switch 122 of module 120a, and transmits an SP signal to the switch 122 of module 120b, which is controlled so that readout in module 120b is started at a timing shifted by one clock.

As described above, according to the fifth embodiment, the control circuit 124 controls so as to change the readout timing of the detection elements 121 between the modules 120 arranged in the column direction, and the readout timing of the detection elements 121 between the modules 120 arranged in the channel direction. Therefore, the X-ray CT device 1 according to the fifth embodiment makes it possible to prevent a large deviation in the readout timing from occurring at the boundaries of the modules 120 in the column direction and the channel direction.

Sixth Embodiment
In the above-described embodiments, the ADC is arranged for each column or each channel. In the sixth embodiment, the ADC is arranged for each module 120.

Figures 13A and 13B are diagrams showing an example of the circuit configuration of the X-ray detector 12 according to the sixth embodiment. Note that although Figures 13A and 13B show the circuit configuration of one module 120, in reality, all of the modules 120 included in the X-ray detector 12 have the same configuration. Hereinafter, parts that have the same configuration as those described in the above-mentioned embodiment are given the same reference numerals as in Figure 3, and descriptions thereof will be omitted.

The X-ray detector 12 according to the sixth embodiment has, for example, an ADC 123a and an ADC 123b for each module 120, as shown in FIG. 13A. Note that the ADC 123a and the ADC 123b may be provided for each module 120, and may be arranged arbitrarily. Although not shown, the ADC 123a and the ADC 123b are connected to a control circuit 124, which controls the timing of signal processing.

The control circuit 124 according to the sixth embodiment controls to change the timing at which a signal is output from the detection element 121 and the timing at which the signal is processed in the ADC. That is, in the sixth embodiment, since an ADC is provided for each module 120, the control circuit 124 controls the switching timing of the switch 122 and the timing of conversion by the ADC when adjusting the readout timing. For example, the control circuit 124 transmits control signals to ADC 123a and ADC 123b so that the electrical signals output from each detection element are converted into digital signals in response to the transmitted SP signal.

The X-ray detector 12 according to the sixth embodiment may also be provided with one ADC 123a for each of the detection elements 1211 and 1212, as shown in FIG. 13B. In such a case, the module 120 has eight switches 122 corresponding to the eight detection elements.

As described above, according to the sixth embodiment, an ADC is arranged for each module. Furthermore, the control circuit 124 controls to change the timing at which signals are output from the detection elements 121 and the timing at which signals are processed in the ADC. Therefore, the X-ray CT device 1 according to the sixth embodiment enables appropriate sequential acquisition even when an ADC is arranged for each module 120.

Other Embodiments
Although the first to sixth embodiments have been described above, the present invention may be embodied in various different forms other than the above-described first to sixth embodiments.

In the above-described embodiment, the X-ray detector 12 has 32 rows of detector elements 121 in the row direction. However, the embodiment is not limited to this, and the X-ray detector 12 can have any number of rows of detector elements 121 as long as the number of rows allows tiling in the row direction.

In addition, in the above-described embodiment, a case has been described in which the modules 120 are arranged in four rows in the channel direction and four rows in the row direction. However, the embodiment is not limited to this, and the modules 120 can be configured in any number of rows.

The term "processor" used in the above description refers to circuits such as a CPU, a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). The processor realizes its functions by reading and executing a program stored in memory 41 or memory 53.

In FIG. 1, a single memory 41 is described as storing a program corresponding to each processing function. However, the embodiment is not limited to this. For example, a configuration may be adopted in which a plurality of memories 41 are distributed and the processing circuit 44 reads out the corresponding program from each memory 41. Also, instead of storing the program in the memory 41, the program may be directly built into the circuit of the processor. In this case, the processor realizes the function by reading and executing the program built into the circuit.

The processing circuitry 44 may also realize functions by using a processor of an external device connected via a network. For example, the processing circuitry 44 reads out and executes a program corresponding to each function from the memory 41, and realizes each function shown in FIG. 1 by using an external workstation or cloud connected to the X-ray CT device 1 via the network NW as a computational resource.

The components of each device according to the above-described embodiments are conceptual and functional, and do not necessarily need to be physically configured as shown in the figures. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figures, and all or part of the devices can be functionally or physically distributed and integrated in any unit depending on various loads and usage conditions. Furthermore, all or any part of the processing functions performed by each device can be realized by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware using wired logic.

According to at least one of the embodiments described above, sequential acquisition can be appropriately performed in an X-ray detector using a module composed of multiple detection elements.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and gist of the invention.

1 X-ray CT device 12 X-ray detector 18 DAS
120 Module 121, 1211, 1212, Detection element 122 Switch 123a, 123b ADC
124, 124a Control circuit 125 Control line

Claims (12)

a plurality of detector arrays each including a plurality of detector elements and each having a port for receiving a readout start signal ;
a control unit that controls the readout timing between the detection arrays to be changed according to a readout order of the detection elements included in each of the detection arrays;
A processing unit that processes signals from the plurality of detection elements;
Equipped with
The control unit executes sequential readout in which reading is performed from multiple detection elements in a fixed readout direction in each detection array by sending a readout start signal to each port of the multiple detection arrays, and sends a readout start signal to the port of a detection array located at the rear in the readout direction between adjacent detection arrays where the readout direction for the multiple detection elements is the same, the readout start signal having a delay in the readout start timing corresponding to the number of detection elements in the previous detection array . a control line connecting the plurality of detection arrays and relating readout timings between the detection arrays in accordance with a readout order of the plurality of detection elements included in each of the plurality of detection arrays;
The X-ray detector according to claim 1 , wherein the control unit controls readout timing between a plurality of detector array groups connected by the control lines. The plurality of detection arrays are arranged in a column direction or a channel direction,
The X-ray detector according to claim 1 , wherein the control unit performs control so as to change readout timings between the plurality of detection arrays arranged in the column direction or the channel direction. The plurality of detection arrays are arranged in a column direction and a channel direction,
The X-ray detector according to claim 1 , wherein the control unit performs control so as to change readout timing between the detection arrays arranged in the column direction and readout timing between the detection arrays arranged in the channel direction, respectively. The X-ray detector according to any one of claims 1 to 4, wherein the processing unit is arranged for each of the detection arrays. The X-ray detector according to claim 5, wherein the control unit controls to change the timing at which the signal is output from the detection element and the timing at which the signal is processed in the processing unit. a plurality of detector arrays each including a plurality of detector elements;
a control line connecting the plurality of detection arrays and relating readout timings between the detection arrays in accordance with a readout order of a plurality of detection elements included in each of the plurality of detection arrays;
A control unit that transmits a read start signal to the detection array;
A processing unit that processes signals from the plurality of detection elements;
Equipped with
the control line connects between a first detection array and a second detection array that are adjacent to each other and have the same readout direction of the plurality of detection elements;
The control unit executes sequential readout in which readout from a plurality of detection elements included in the first detection array and readout from a plurality of detection elements included in the second detection array are executed sequentially along the readout direction by sending a readout start signal to the first detection array located at the front stage in the readout direction, and transmits readout start signals to simultaneously start readout to adjacent third detection arrays and fourth detection arrays having opposite readout directions for the plurality of detection elements . The plurality of detection arrays are arranged in a column direction or a channel direction,
The X-ray detector according to claim 7 , wherein the control lines connect between the plurality of detector arrays arranged in the column direction or the channel direction. The plurality of detection arrays are arranged in a column direction and a channel direction,
The X-ray detector according to claim 7 , wherein the control lines connect between the detector arrays arranged in the column direction and between the detector arrays arranged in the channel direction. The X-ray detector according to any one of claims 7 to 9, wherein the processing unit is arranged for each of the detection arrays. The X-ray detector according to claim 10, further comprising a control unit that controls the processing unit to change the timing at which the signal is processed. An X-ray CT device equipped with an X-ray detector according to any one of claims 1 to 11.

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