JP2008022961A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus which eliminates difficulty of a determination accompanying setting of a rotational scanning speed and achieves both the generation of images satisfying the image quality required by a user and a reduction in the measurement time. <P>SOLUTION: A data set acquired by an X-ray detecting part for each rotational scan is acquired, and an accumulated composite image is generated by using a series of data sets from the beginning of the rotational scan to now by using the X-ray CT apparatus equipped with an X-ray measurement unit including an X-ray generating part and the X-ray detecting part and a rotating mechanism for rotating the X-ray measurement unit. The user confirms the acquisition of the images of the sufficiently-high quality while watching a representative accumulated composite image displayed on a display part and can end the generation of the accumulated composite image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an X-ray CT apparatus, and more particularly to rotational scanning control and image processing technology.

  An X-ray CT apparatus is an apparatus that forms a tomographic image or the like based on information obtained by transmitting a rotationally scanned X-ray beam to a subject. In addition to being used for diagnosing human diseases, the X-ray CT apparatus is also used for measuring animals and other objects other than the human body for the purpose of research and experiments. X-ray CT apparatuses for animals are used in the field of new drug development. Patent Document 1 describes a technique related to an X-ray CT apparatus for animals, and specifically describes a technique related to image formation capable of grasping the distribution state of soft tissue.

JP 2005-192656 A

  In the X-ray CT apparatus, the X-ray beam is rotationally scanned with respect to the subject as described above. One tomographic image is formed by one rotation scanning over a predetermined angular range. As the rotational scanning method, a method of continuously performing rotational scanning in the same rotational direction, a method of repeatedly performing reciprocating rotational scanning within a predetermined angle range, and the like are known. The latter technique is often used in relatively inexpensive X-ray CT apparatuses for animals.

  In order to improve the image quality of a tomographic image as a CT image, it is desired to improve the SN ratio of the image. For this purpose, an X-ray CT apparatus is generally equipped with a function for switching the rotational scanning speed. However, it is usually difficult to select a rotational scanning speed that matches the image quality required by the user. In some cases, the rotational scanning speed is excessively slow (necessity of processing efficiency), or conversely, the rotational scanning speed is too high to obtain the expected image quality (the required image quality cannot be obtained). Problem) occurs. If the setting of the rotational scanning speed is inappropriate, the rotational scanning may be performed again.

  Incidentally, the X-ray CT apparatus for animals is used in various fields for research and experiments. Particularly, in the field of new drug development, it has good responsiveness capable of forming CT tomographic images in a short time. A device is sought. That is, various types of animals such as guinea pigs, rats, mice, hamsters, rabbits, dogs, cats, and the like can be imaged using the X-ray CT apparatus for animals. In addition, a tissue piece separated from these animals may be a subject of imaging. Since there are various types of subjects, a user who performs imaging may be unsure of what imaging conditions (especially rotational scanning speed) are appropriate for the apparatus.

  An object of the present invention is to provide an X-ray CT apparatus capable of avoiding the difficulty of determination associated with setting of the rotational scanning speed and realizing both the required image quality and the reduction of measurement time.

  (1) The present invention provides an X-ray measurement unit including an X-ray generation unit that generates X-rays irradiated to a subject, and an X-ray detection unit that detects X-rays transmitted through the subject; A rotation mechanism that rotates the line measurement unit around the subject, and a data set acquired by the X-ray detection unit for each rotation scan by the rotation mechanism are input, and a series of operations from the start of the rotation scan to the present Data processing means for forming an integrated composite image reflecting the data set, a display unit for displaying the integrated composite image that is repeatedly updated from the start of the rotational scanning, and an image from the user in the update display process of the integrated composite image The present invention relates to an X-ray CT apparatus comprising: a detecting unit that detects an approval operation; and a control unit that ends the formation of the integrated composite image when the image approval operation is detected.

  According to the above configuration, the rotation scanning of the measurement unit is repeatedly executed by the rotation mechanism. In that case, the integrated composite image is displayed on the display unit. That is, the integrated composite image created on the basis of the data set obtained by the rotational scanning executed so far is continuously displayed. The integrated composite image is updated each time the rotational scanning is performed, and the image quality is gradually improved. In other words, the image quality gradually grows. When the user who observes the integrated composite image displayed on the display unit recognizes that the image quality is satisfactory, the user performs an image approval operation, and the formation of the integrated composite image is terminated by using the image approval operation. In that case, rotational scanning may be stopped as necessary. Alternatively, the same processing as described above may be applied to the next tomographic image forming position by continuing the rotation scanning as it is.

  This is reasonable because the user can actually see the image and stop the measurement, and there is no waste in the measurement. Even if you are imaging a subject that you are measuring for the first time and you do not know what X-ray imaging conditions should be set, without wasting time by repeating trial and error, A good image can be obtained. Since the user decides to cancel the integrated shooting, even if the entire image does not have a good image quality, the shooting can be stopped when the image quality of the portion in which the user is interested has improved. That is, it is possible to obtain an image having a necessary minimum image quality without causing time waste without causing excessive image quality.

  As described above, when the optimum number of rotational scans is found with the user's judgment, when the measurement is performed at the next tomographic image formation position for the same subject, the corresponding number of rotational scans are performed. It may be automatically performed (that is, user approval may be omitted and the preset operation may be switched). In the past measurement, when the optimum number of rotational scans is determined by the above method, it may be used in the current measurement to prioritize the reproducibility of the measurement conditions. In addition, when the optimum number of rotation scans is found, it can be converted into a rotation speed, and the rotation speed can be set in the subsequent measurement. In the above configuration, a high speed can be set as the rotational scanning speed, and the rotational scanning speed can be selected by the user. In any case, it is desirable to set conditions such as the rotational scanning speed so that the measurement time of the subject can be shortened. The rotational scanning may be continuously performed only in one direction, but the rotational scanning may be performed by reciprocating in both directions. Since the latter is generally mechanically simple, it is desirable to adopt the latter when constructing an inexpensive animal X-ray CT apparatus. As the X-ray detector, a one-dimensional array type detector, a two-dimensional array type detector, or the like can be used. The rotation mechanism rotates the measurement unit relative to the subject. In this case, the measurement unit may be rotationally driven. However, the subject side may be rotationally driven. It is desirable to form an integrated composite image using each image that has undergone reconstruction calculation (for example, by averaging), but for example, after performing an averaging process on a series of data sets before the reconstruction calculation Thus, an image (integrated composite image) may be formed by reconstruction calculation based on the processed data set.

  Preferably, the data processing means includes a reconstruction calculation unit that forms a tomographic image based on a data set acquired for each rotational scan, and an averaging based on the tomographic image formed for each rotational scan. And an averaging calculation unit that forms the integrated composite image by processing.

  According to the above configuration, a tomographic image is formed based on a data set acquired for each rotational scan, and an integrated composite image averaged based on a plurality of tomographic images formed according to each data set is formed. The Therefore, the subject image information acquired by the plurality of data sets is collectively reflected on one integrated composite image.

  Preferably, the display unit displays information representing the number of rotation scans up to the present together with the integrated composite image in the update display process of the integrated composite image.

  According to the above configuration, since the integrated composite image and the number of rotation scans are displayed, in order to reach the image quality in that state while confirming that the image quality of the tomographic image is gradually improved by the integrated composite processing The number of necessary rotational scans can be known. If the rotational scanning speed is determined, the time taken to reach a good image quality can be calculated from the number of rotational scanning.

(2) The present invention includes an X-ray generation unit that generates X-rays irradiated to a subject, and a plurality of two-dimensionally arranged X-ray detection elements that detect X-rays transmitted through the subject. An X-ray detection unit comprising: an X-ray detection unit; a rotation mechanism for rotating the X-ray measurement unit around the subject; and the X-ray detection unit for each rotational scan by the rotation mechanism. Data processing means for inputting a plurality of data sets corresponding to a plurality of image forming positions and forming an integrated composite image in which a series of data sets from the start of rotational scanning to the present are reflected for each image forming position; A display unit that displays all or part of a plurality of integrated composite images corresponding to the plurality of image forming positions, and detects an image approval operation from a user in the process of updating or displaying all or part of the plurality of integrated composite images Detection means to And control means for ending the formation of the plurality of integrated composite image when detecting the image approval operation, an X-ray CT apparatus characterized in that it comprises a.

  According to the above configuration, a plurality of data sets can be acquired by rotating an X-ray detection unit configured by a plurality of two-dimensionally arranged X-ray detection elements around a non-subject. The acquired plurality of data sets becomes a series of data sets accumulated from the start of the rotational scanning, and is used for forming a plurality of integrated composite images. The user can approve all or part of the integrated composite images displayed on the display unit, and the approval operation can end the formation of a plurality of integrated composite images.

  Preferably, one or a plurality of representative integrated composite images that are a part of the plurality of integrated composite images are displayed on the display unit. According to the above configuration, in a state where a plurality of displayable images are acquired, it is possible to determine the image quality by representatively selecting a screen on which the user can most easily determine the pass / fail level of the image. Alternatively, the image quality can be determined using an image in which a region of interest to the user is most captured.

  As described above, according to the present invention, the required image quality can be realized and the measurement time can be shortened.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows an operation principle diagram of tomographic imaging performed by an X-ray CT apparatus according to an embodiment of the present invention. FIG. 1 shows the formation of tomographic images (CT images) in order of time. In FIG. 1, a total of five stages are illustrated, and are shown from the left side to the right side in order of early time.

  The upper part of FIG. 1 shows a movable unit 50 for X-ray imaging of a subject. The five circular schematic figures 86A to 86E shown in FIG. 1 show that the X-ray measurement module, that is, the unit including the X-ray generator 52 and the X-ray detector 60 rotates around the subject. FIG. A circular arrow written so as to surround the circumference of the circle indicating the movable portion 50 represents the direction in which the movable portion 50 rotates around the container 24 in the clockwise direction or the counterclockwise direction. Although a specific configuration of the movable unit 50 will be described later with reference to FIG. 4, the movable unit 50 has a container 24 in which a subject is placed at the center thereof. Incidentally, FIG. 2 shows the state of the mouse 84 as the subject housed in the container 24. A tomographic image is formed by using a mouse 84 housed in a container 24 as shown in FIG. 2 at the center of the movable portion 50 and using it as a subject. It is also possible to rotate the container relative to the measurement unit.

  The value I shown in the upper part of FIG. 1 indicates the number of tomographic images serving as a basis for forming a tomographic image (display image) as a displayed integrated composite image. That is, the value of I is an integrated number for image composition. In the integrated number I = 1, that is, in the first rotation operation, a state in which the movable portion 50 rotates clockwise is shown. In the one rotation scan, the X-ray detector 60 outputs a plurality of data sets corresponding to the detected amount of X-rays, and can reconstruct these data sets to form one tomographic image. .

  In the middle part of FIG. 1, the whole images (scout images) showing the entire shape of the mouse are shown as 88A to 88E. In these whole images 88A to 88E, the Z axis is defined along the direction of the body length of the mouse. In the first rotational scanning with the integrated number I = 1, one Z coordinate of z1 is one sheet. A state in which a tomographic image is acquired is shown. A tomographic image 90A obtained based on one rotation scan is shown in the lower part of FIG. Since the image quality of an image obtained by one rotation scan depends on the type of subject, the speed of the rotation scan, and the like, a clear image cannot always be obtained by one rotation scan. As described in detail below, in this embodiment, the user who observes the display image instructs the stop of the rotational scanning when a satisfactory image quality is obtained. Therefore, if the image quality of the image corresponding to the first rotational scanning can be satisfied, it is possible to input an instruction to stop the rotation at this point.

  Next, the state of the second rotational scanning is shown on the right side of the above-mentioned integration number I = 1. In the second rotational scanning, a state is shown in which an image is formed by rotating the movable portion 50 counterclockwise. Even in this case, X-ray scanning is performed on the same cross-sectional portion of the z1 coordinate in the Z-axis direction. Each tomographic image obtained by the two rotational scans of the integration numbers I = 1 and I = 2 is averaged by integration synthesis. The averaging process is conceptually processed as a superposition of images, and averaging is performed at the pixel level constituting the image.

  Further, when the next-stage rotational scanning is performed, the integration number becomes I = 3, and the third image formation is performed. The third time is performed using a clockwise rotational scan as in the first time. The coordinate in the Z-axis direction is also z1. The tomographic image 90 </ b> C obtained based on the third rotation scan is subjected to integration synthesis processing on the integration synthesis image 92 </ b> B of the first and second images. The obtained image 92C is formed by integration and synthesis processing by adding and averaging three images of the first tomographic image 90A, the second tomographic image 90B, and the third tomographic image 90C at the pixel level. . By performing averaging processing using a plurality of tomographic images obtained by a series of conventional rotational scans, the noise component at the pixel level is canceled out, and the image quality of the tomographic image after integration synthesis can be improved. .

  Similarly, when the rotational scanning is continued and the cumulative number is added, the data set that forms the basis of image formation obtained by the rotational scanning is similarly obtained by alternately repeating the clockwise rotation and the counterclockwise rotation. Each time, the pixel level is averaged (cumulative addition or integration synthesis), and the tissue and bone tomographic images of the object are displayed on the display unit as clearer images. .

  In FIG. 1, the state of integration synthesis at I = n is shown as an example when the integration number is accumulated to 4 or more. z1 does not change, and all tomographic images at the same Z coordinate are obtained. An image obtained by the integration synthesis and the averaging process is shown in 92D. In general, each time the integration number increases, noise is reduced and a clear image is obtained. The determination that the image has become clear is made by the user. The user determines that a clear image in a sufficient state has been obtained from the integrated composite image 92D at the stage of the integrated number I = n, and performs an interrupt command operation from the keyboard, mouse, etc. provided in the arithmetic control unit 12 I do. In this manner, the rotation scanning interruption command is instructed by the user's manual operation.

  When the interruption process is performed, the integration and synthesis process for z1 of the Z-axis coordinate is completed, and a tomographic image is formed at another Z coordinate. In general, since the movement pitch ΔZ between tomographic images is determined in obtaining a tomographic image, new tomographic images sliced at intervals of the movement pitch ΔZ can be obtained. In the image example 88E in FIG. 1, it is shown that a tomographic image is obtained at a coordinate position of z2 different from z1. The obtained image 90E is the first image in z2. Since this portion is the first tomographic image of a tomographic part different from the position of the mouse body, the level of the image is the same level as the tomographic image 90A obtained by the first rotational scanning in the z1 coordinate described above. Similarly, scanning with a plurality of rotational motions is also performed on the Z coordinate position of z2. Since the number of times n set by z1 is also used when performing integration synthesis at the position of z2, a new image is formed by performing integration integration n times for z2.

  Images are formed on the basis of the operation principle as described above. In this method, the image quality of the displayed image gradually increases according to the number of rotation scanning repetitions (image growth in terms of image quality). ) In such a display update process, the user determines the timing when the image has reached the required quality and performs the interruption process, so that the minimum image level is set so that the target tissue can be observed. In addition, since the image level is limited by the number of times of shooting (rotational scanning), the shooting time does not become extremely long, and an image having a quality that can achieve the shooting purpose can be obtained in the shortest time. Obtainable. When an interruption instruction is input at a timing during the rotational scanning, the rotation stops when all the rotational scanning is completed. In that case, an image formed by reconstructing the last acquired data set may be reflected in the integrated composite image (in this case, the image quality at the time when the user determines approval of image quality is slightly different). It ends with good image quality), and it may be discarded. When the image formation is performed instantaneously, it is desirable to adopt the former. An image to be displayed for interruption determination may be enlarged and displayed. Further, the attention site in the image may be enlarged and displayed. When displaying an image, the latest image and the past image may be displayed simultaneously so that a change in image quality can be easily recognized visually.

  FIG. 3 shows an example of hardware of an X-ray CT apparatus for performing image synthesis by the above-described integration synthesis and averaging processing. This X-ray CT apparatus is an apparatus for performing CT measurement particularly on mice such as mice and rats. Of course, other animals, particularly small animals, can be measured, and a part of the animal tissue can also be measured.

  This X-ray CT apparatus is roughly divided into a measurement unit 10 and a calculation control unit 12. The measurement unit 10 has a main body 16 having a gantry 18. An opening is formed in the upper surface 16A of the main body 16, and an arm 26 projects upward from the opening. The arm 26 forms a part of a slide mechanism described later, and the arm 26 is connected to a container 24 described later, and slides in the direction of the central axis. On the other hand, measurement units (X-ray generator, X-ray detector), which will be described later, are accommodated in the gantry 18 and rotate around the rotation center axis. A hollow portion 18A is formed in the central portion of the gantry 18 in the direction of the rotation center axis. The container 24 is a capsule that houses a small animal as a subject, and the container 24 has a substantially cylindrical shape in the present embodiment, and is arranged in a state in which the container center axis coincides with the rotation center axis. Specifically, the base end portion 76 of the container 24 shown in FIG. 2 is detachably attached to the upper end portion of the arm 26 described above. In this case, examples of the attachment / detachment mechanism include various engagement mechanisms or screwing mechanisms. As described above, the container 24 has a hollow cylindrical shape, and a small animal is disposed in the container 24.

  An operation panel 20 is provided on the upper surface 16A of the main body 16, and the operation panel 20 includes a plurality of switches, indicators, and the like. Using this operation panel 20, the user can operate the operation of the apparatus at the measurement site.

  Next, the arithmetic control unit 12 will be described. The arithmetic control unit 12 is electrically connected to the measurement unit 10 by a cable 14. The arithmetic control unit 12 is configured by a normal computer system or the like, and specifically includes a processor 30, a display 32, a keyboard 36, a mouse 38, a storage device 34, a printer 40, and the like. The operation control unit 12 controls the operation of the measurement unit 10, and a CT image is configured based on data transmitted from the measurement unit 10.

  By the way, in the apparatus of this embodiment, the rotation speed of the measurement unit in the gantry 18 can be switched. For example, the high-speed scanning mode in which one rotation scan is completed in 4.5 seconds, or one time in 18 seconds. The user can select the rotation speed from a mode for ending the rotational scanning, a mode for ending the rotational scanning once every 36 seconds, or the like. In the user determination mode in which the user instructs to interrupt the rotation scanning, a preset rotation speed is set. In this case, the maximum speed may be set, but it may be desirable to set a low speed rather in consideration of the acceleration / deceleration period at each turn-back time in the reciprocating rotational motion. In the apparatus of the present embodiment, as another operation mode of the above-described user determination mode, there is a mode in which rotational scanning is automatically executed a predetermined number of times. The keyboard 36 and mouse 38 correspond to means for performing an image quality approval operation, that is, a rotation scanning interruption instruction. A voice or other input device may be used.

  FIG. 4 is a block diagram showing the components of the X-ray CT apparatus shown in FIG. An X-ray generator 52 is provided on one side and an X-ray detector 60 is provided on the other side with the rotation center axis O therebetween. A collimator 54 is provided on the irradiation side of the X-ray generator 52. The X-ray generator 52 generates a divergent or fan-shaped (here, fan-beam shaped) X-ray beam 56 as shown. On the other hand, the X-ray detector 60 is configured as a plurality of (for example, 100) X-ray sensors arranged in a line, and an X-ray receiving opening is set according to the opening angle of the X-ray beam 56. Incidentally, the arrangement of the plurality of X-ray sensors may be linear or arcuate. Note that a two-dimensional array X-ray detection unit described later can also be used. A belt is wound around the motor 66A, and the rotational force is transmitted by the rotational movement of the movable portion 50 by rotating the belt. The movable unit 50 is mounted with various mechanisms whose relative positional relationship should not be changed by the rotation thereof. The gantry rotation mechanism 66 is a mechanism that rotationally drives the entire components mounted on the gantry rotation mechanism 66. The gantry rotating mechanism 66 has a motor 66A for generating the driving force.

  Next, the arithmetic control unit 12 will be described. As described above, the display unit 32, the storage device 34, the keyboard 36, the mouse 38, and the like are connected to the processor 30. The processor 30 is configured by a CPU, an operation control program, an image processing program, and the like. The processor 30 includes an operation control unit 44, a reconstruction calculation unit 46, and an averaging calculation unit 100. The operation control unit 44 controls the overall operation of the measurement unit 10. The reconstruction calculation unit 46 executes a calculation for forming one CT image (tomographic image) based on a lot of data (data set per one rotation scan) obtained by the X-ray beam rotation scan. Various known methods can be used for the reconstruction operation. The averaging calculation unit 100 uses pixel data constituting a plurality of tomographic images formed for each rotational scan as a calculation target, and forms an integrated composite image by averaging processing. The image processing program executed by the processor 30 executes an integration synthesis process of tomographic images formed for each rotational scan. The operation control program includes a module for controlling the operation in the user determination mode.

  FIG. 5 shows a flowchart of operations performed in the processor 30 in the arithmetic control unit 12 for forming the integrated composite image shown in FIG.

  In S101, 1 is substituted into the integration number I as an initial value. In S102, movement for moving the Z coordinate is performed. The Z-axis movement performed in S102 corresponds to moving the CT tomography plane to the z1 coordinate position shown in the principle diagram of FIG. In S103, the movable unit 50 including the measurement unit starts to rotate. In the present embodiment, the rotational motion in S103 does not need to be rotated once, and a tomographic image can be reconstructed if the rotational angle can reciprocate an obtuse angle of 180 ° + α. (For example, α is about 38 °.) In S104, one tomographic image is formed by one rotational movement. In S105, averaging at the pixel level is performed using the newly obtained tomographic image and the tomographic image accumulated in the past. In S106, the averaged tomographic image is displayed on the screen. When the integration number I is 1, since there is no past accumulated image, the first image is displayed as it is. Incidentally, since it takes a considerable amount of processing time to reconstruct a tomographic image, other processing such as rotational scanning may be executed in advance while the tomographic image display processing is being executed. After the average image is displayed, in S107, it is determined whether or not an instruction to interrupt the integration of the images has been issued. The interruption command is given by an input command from the user using the keyboard 36 or the mouse 38. If there is an interruption command, the process proceeds to S113, and the value of the specified maximum value (PresetMAX) is overwritten and updated by the value of the integrated number I at the time when the interruption process occurs. If there is no interruption command, the process proceeds to S108. In S108, it is determined whether or not the value of the integration number I has reached the specified maximum value (PresetMAX).

  If the integration number I is less than the specified maximum value (PresetMAX), the process proceeds to S109 and the integration number I is incremented. Thereafter, in S110, the rotation direction of the movable unit 50 is switched to the opposite direction. After the direction is instructed, the rotation of the movable unit 50 is resumed in S103. On the other hand, if the integration number I is equal to or greater than the specified maximum value (PresetMAX), the process proceeds to S111. In S111, it is determined whether or not the amount of movement in the Z-axis direction has reached the maximum value Max. If Z is less than the specified maximum value (Max), the process proceeds to S112, and the movement pitch (ΔZ) in the Z-axis direction is added to the movement command value Z. After the addition of the movement pitch ΔZ, the process proceeds to S101, and the integration number I is returned to the initial value 1 in S101.

  On the other hand, if the movement instruction value Z is equal to or greater than the prescribed maximum value (Max), the process proceeds to S112 and the photographing is finished. Through the above process, the averaging process of integration synthesis and the screen display are performed.

  FIG. 6 is a diagram illustrating an example of the screen layout of the integrated composite image. A screen 104 shown in FIG. 6 is a one-screen layout displayed on the display 32 shown in FIG. In the upper part of the screen 104, for example, an area 106 for displaying solid information of the mouse 84 that is the subject is provided. On the left side of the screen 104, an overall image (scout image) 108 showing the overall shape of the mouse 84 is displayed. On the right side of the screen 104, a tomographic image (integrated composite image) 110 of the mouse 84 is displayed. In the center of the screen 104, an “interrupt button” 112 and a “discard button” 114 are popped up. The interrupt button 112 is a button for the user to click when approving that the image quality of the integrated composite image has become sufficient. The discard button 114 is a button used to discard the accumulated image when, for example, the animals as the subject have moved and the imaging cannot be continued. A marker 107 indicating a position in the Z-axis direction is displayed on the entire image 108, and one tomographic image 110 at the position indicated by the marker 107 is displayed. The marker 107 can be slid and moved within a displayable area 109 that indicates a collection of a plurality of displayable tomographic images.

  In addition to performing CT measurement for one position in the Z-axis direction, CT measurement is simultaneously performed at a plurality of positions in the Z-axis direction using a two-dimensional detector composed of a plurality of X-ray detection elements as an X-ray detector. In this case, the above-described method can be applied.

  In the above case, a plurality of data sets are acquired simultaneously per one rotation scan corresponding to a plurality of X-ray detection element arrays arranged in the Z-axis direction. Each data set (that is, the above-described integrated composite image forming process is executed for each position, whereby a plurality of integrated composite images (display images) are obtained simultaneously. For example, an X-ray detection element array When there are 60 columns, 60 display images are simultaneously formed, and all of them may be displayed to allow the user to determine how far to continue the rotational scanning, but the user can observe and evaluate If it is complicated, it is desirable to display only one or a plurality of representative images, and to allow the user to make a judgment based on the one or more representative images. The image may be selected, or the user may select the image to be displayed, and in any case, all the formed synthesized images are CT tomographic images. As an image, the image is stored in the storage unit, and the images are read out as necessary.The information indicating where the representative image was acquired is displayed as numerical information or a projection displayed together with the tomographic image It may be displayed as a marker on an image (a scout image) In general, measurement of a scout image is performed prior to CT measurement, and in this case, the measurement unit does not rotate and scans the Z-axis. When storing an image, data indicating the number of integrations can be added as attribute information, and the number of rotational scans required for the next measurement is referred to for the information. In addition to the above, as attribute data, the position in the Z-axis direction and the rotation speed may be input. It is possible to increase the information, such as magnification.

It is a principle figure of the integration synthetic image formation performed in a X-ray CT apparatus. It is a perspective view which shows the usage example of the container with which an X-ray CT apparatus is mounted | worn. It is a perspective view which shows the whole structure of a X-ray CT apparatus. It is a block diagram which shows the whole structure of a X-ray CT apparatus. It is a flowchart which shows the operation | movement at the time of forming an integrated image. It is a figure which shows an example of the screen layout displayed on a display part.

Explanation of symbols

  24 containers, 50 moving parts, 52 X-ray generator, 60 X-ray detector, 88A, 88B, 88C, 88D, 88E scout image, 90A, 90B, 90C, 90D, 90E tomographic image, 94 composite averaging process, 92B , 92C, 92D integrated composite image, 104 screen, 106 solid information display area, 107 marker, 108 scout image, 109 displayable area, 110 integrated composite image, 112 interrupt button, 114 discard button.

Claims (5)

An X-ray measurement unit comprising: an X-ray generation unit that generates X-rays irradiated on the subject; and an X-ray detection unit that detects X-rays transmitted through the subject;
A rotation mechanism for rotating the X-ray measurement unit around the subject;
Data processing means for inputting a data set acquired by the X-ray detection unit for each rotational scanning by the rotational mechanism and forming an integrated composite image reflecting a series of data sets from the start of the rotational scanning to the present; ,
A display unit that displays an integrated composite image that is repeatedly updated from the start of the rotational scanning;
Detecting means for detecting an image approval operation from the user in the update display process of the integrated composite image;
Control means for ending the formation of the integrated composite image when detecting the image approval operation;
X-ray CT apparatus characterized by including. The X-ray CT apparatus according to claim 1,
The data processing means includes
A reconstruction calculation unit that forms a tomographic image based on a data set acquired for each rotational scan;
An averaging calculation unit that forms the integrated composite image by an averaging process based on a tomographic image formed for each rotation scan;
X-ray CT apparatus characterized by including. The X-ray CT apparatus according to claim 1,
The X-ray CT apparatus, wherein the display unit displays information representing the number of rotational scans up to the present together with the integrated composite image in the update display process of the integrated composite image. An X-ray generation unit that generates X-rays irradiated on the subject, and an X-ray detection unit configured by a plurality of two-dimensionally arranged X-ray detection elements that detect X-rays transmitted through the subject. An X-ray measurement unit provided;
A rotation mechanism for rotating the X-ray measurement unit around the subject;
A plurality of data sets corresponding to a plurality of image formation positions acquired by the X-ray detection unit for each rotation scan by the rotation mechanism are input, and a series of processes from the start of the rotation scan to the present for each image formation position. Data processing means for forming an integrated composite image reflecting the data set;
A display unit for displaying all or part of a plurality of integrated composite images corresponding to the plurality of image forming positions;
Detecting means for detecting an image approval operation from a user in an update display process of all or a part of the plurality of integrated composite images;
Control means for terminating the formation of the plurality of integrated composite images when the image approval operation is detected;
X-ray CT apparatus characterized by including. The X-ray CT apparatus according to claim 4.
The X-ray CT apparatus, wherein the display unit displays one or more representative integrated composite images that are a part of the plurality of integrated composite images.

Images