JP4083675B2 - X-ray measuring apparatus and specimen identifying tool used therefor - Google Patents

Description

  The present invention relates to an X-ray measurement apparatus and a sample identification tool used therefor, and particularly to a sample identification technique based on image analysis.

  As an X-ray measuring apparatus, an X-ray CT apparatus, an X-ray apparatus, an X-ray bone density measuring apparatus, and the like are known. Here, taking an X-ray CT apparatus as an example, the X-ray CT apparatus is used for measurement of a human body or a non-living object, for example, a small animal (mouse, hamster, guinea pig, rat, dog, etc.) subjected to animal experiments. , Cats, etc.). That is, a plurality of tomographic images (CT images) are formed for small animals, and the experimental results are evaluated based on these images. Usually, in animal experiments, a large amount of small animals are used at one time, and image data after CT measurement is managed for each small animal. In managing such image data, it is necessary to give identification information to each specimen. However, if the user inputs identification information at the time of CT measurement of each specimen, it becomes very complicated and burdensome. Furthermore, problems such as mistakes are likely to occur. These problems can be pointed out similarly in cases other than small animals, and can also be pointed out in cases other than CT measurement. In the system described in Patent Document 1, sample management is performed using radio.

JP-A-11-276002

  As described above, there is a problem that it is very cumbersome and burdensome when the user inputs sample information for each sample to be subjected to X-ray measurement. In addition, there is a problem that the sample is easily mixed.

  An object of the present invention is to allow sample information to be taken in easily.

  Another object of the present invention is to make it possible to associate a sample and a measurement result without error.

(1) An X-ray measurement apparatus according to the present invention is provided on a specimen, and a specimen identification tool having a specimen identification code, and X that irradiates the specimen with X-rays and detects X-rays transmitted through the specimen. Line measuring means, image forming means for forming a specimen image based on the X-ray detection data, and code reading means for reading the specimen identification code from an image portion of the specimen identifying tool included in the specimen image. It is characterized by including.

  According to the above configuration, the sample identifying tool is attached to the sample, and the sample is identified using the sample identifying tool. Specifically, a specimen image is formed from detection data obtained by irradiating the specimen with X-rays, and a specimen identification code included in the specimen identification tool is read by analyzing the specimen image. Since the specimen itself is provided with the specimen identification tool, it is possible to prevent the difference between specimens, and the specimen identification code can be read by image analysis, so that it is possible to eliminate the trouble of user input and input errors.

Test body organism, particularly murine, not to demand that a small animal, such as hamster. When a specimen identification tool is attached to a small animal, it is desirable to attach the specimen identification tool to a site that is away from the measurement target site. A tail is preferable as the part, and if the structure is inserted through the tail, mounting is easy. The specimen identifying tool is made of a material that can be recognized on the X-ray detection data. However, when visual confirmation is required, a character, a symbol, or the like may be separately added thereto. Each bit constituting the specimen identification code has a binary value or a multi-value. The bit string functions like a barcode. In reading the specimen identification code, the entire image may be the analysis target, or if the position of the specimen identification tool is specified, a specific area or a specific line may be the analysis target.

  When X-ray measurement is performed simultaneously or sequentially on a plurality of specimens, that is, when a plurality of specimens are set simultaneously on the X-ray measurement apparatus, a specimen identification tool is attached to each specimen, and A specimen identification code is read for each specimen.

  Preferably, the specimen identification code is expressed using a difference in X-ray attenuation. Preferably, the specimen identification code is configured as a bit string composed of a plurality of bits, and each bit configuring the bit string is configured by a first element or a second element having different X-ray attenuation amounts. Preferably, the first element is constituted by a first member having an X-ray attenuation amount larger than an X-ray attenuation amount of bone contained in the specimen, and the second element is an X-ray of the first member. It is constituted by a second member or an air layer having an X-ray attenuation amount smaller than the attenuation amount. According to this configuration, the bit value can be determined with high accuracy. If the first member is made of a material having a higher attenuation than the bone, the problem of misidentifying the bone as the first member can be solved.

  Desirably, the sample identification tool is mounted on the outer surface of the sample or embedded in the sample. For the specimen identification tool on the outer surface of the specimen, various methods such as crimping (fixing), fixing with an adhesive tape, fixing like a tag with a string, and punch fixing can be used. In the case of embedding in a specimen, methods such as insertion and insertion and insertion after suture and before suturing can be used. It is desirable to configure the sample identification tool so that the sample identification code can be read regardless of the mounting direction.

  Desirably, the sample is a small animal, and the sample identification tool has an insertion hole through which the tail of the small animal is inserted. Since the tail of a small animal used in animal experiments or the like is usually a part other than the measurement target, if a specimen identification tool is attached to such a part, measurement will not be disturbed. It is convenient if the tail can be inserted and fixed. In addition to the tail, ears and limbs can be raised.

  Preferably, the code reading unit includes a reference coordinate detection unit that detects a reference coordinate for an image portion of the sample identification tool on the sample image, and a bit of each bit constituting the sample identification code based on the reference coordinate. Bit coordinate specifying means for specifying bit coordinates, and pixel value analyzing means for reading the specimen identification code by performing pixel value analysis at the bit coordinates of each bit.

  According to the above configuration, the reference coordinates of the specimen identification tool are specified, and one or a plurality of reading coordinates for each bit are determined based on the reference coordinates, and a bit value reading process is performed for each coordinate. The sample identification code may include a start bit, a parity bit, and the like. The start bit defines the top coordinate, and the parity bit is for determining a read error. You may make it perform an error correction encoding process more highly.

  Preferably, the pixel value analyzing means includes means for performing a scan process on the bit coordinates of each bit to specify a maximum pixel value, and means for determining a bit value based on the maximum pixel value. In determining the maximum pixel value, a condition such that a plurality of pixels having the maximum pixel value is greater than or equal to a predetermined number or is continuous can be added. By using the maximum pixel value, it is possible to avoid the problem of misidentifying bones and noise in the specimen.

  Preferably, it includes means for managing the measurement result obtained for the sample in association with the sample identification code of the sample. According to this configuration, the X-ray measurement result can be reliably managed in association with the specimen identification code, and advantages such as prevention of mistakes can be obtained.

(2) Further, an X-ray CT apparatus according to the present invention is provided in a small animal as a specimen, and a specimen identification tool having a specimen identification code, and X-ray that irradiates the small animal with X-rays and transmits through the small animal. An X-ray measuring means for detecting a scout, a scout image forming means for forming a scout image based on the detection data of the X-ray, and a code for reading the specimen identification code from an image portion of the specimen identifying tool included in the scout image Reading means; tomographic image forming means for forming a CT tomographic image of the small animal based on the X-ray detection data; and means for managing the CT tomographic image using the read specimen identification code It is characterized by that.

(3) A sample identification tool according to the present invention is a sample identification tool attached to a sample and having a sample identification code composed of a plurality of bits, and each bit has a different X-ray attenuation amount. The first element is composed of a first member having a larger X-ray attenuation amount than the bone of the specimen, and the second element is attenuated of X-ray than the soft tissue of the specimen. It is characterized by being configured as a small second member or air layer.

  As described above, according to the present invention, sample information can be easily captured. According to the present invention, the specimen and the measurement result can be associated with each other without error.

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

  FIG. 1 shows an example of an X-ray CT apparatus. This X-ray CT apparatus is an apparatus for performing CT measurement particularly on mice such as mice, rats, mice, guinea pigs and hamsters. 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. The arm 26 is connected to a container 24 described later, and slides (moves and scans) it in the direction of the rotation center 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 hollow portion 18A is a non-penetrating type, but may be a penetrating type.

  In this embodiment, the container 24 accommodates one or a plurality of specimens (such as small animals). The container 24 has a substantially cylindrical shape in the present embodiment, and is disposed in a state where the container center axis coincides with the rotation center axis. Specifically, the base end portion 76 of the container 24 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 in this embodiment, one or a plurality of small animals are arranged. In this configuration, the hair of the small animals is directly attached. Contacting the gantry 18 can be prevented. In addition, it is possible to prevent the problem that small animal excrement or detached hair is released to the outside. Further, as will be described later, since it becomes possible to restrain the small animal in a fixed manner, it is possible to prevent problems such as image blurring when the CT image is reconstructed. It is desirable to prepare and selectively use a plurality of types of containers having different sizes and shapes.

  After the container 24 is attached to the arm 26, the arm 26 is driven forward along the direction of the rotation center axis, whereby the container 24 is inserted into the cavity 18A of the gantry 18. At the time of CT measurement, the X-ray beam is rotationally scanned at each position in the specimen, and accordingly, the container 24 is positioned stepwise. When a scout image (corresponding to an X-ray image) is acquired in advance, the specimen is linearly scanned in the direction of the rotation center axis without performing rotational scanning of the X-ray beam.

  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. A plurality of casters 22 are provided below the main body 16. Incidentally, the height of the measurement unit 10 is, for example, 100 cm.

  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 measurement unit 10 and the calculation control unit 12 may be provided in the same room, or may be installed in different places. 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. This CT image usually corresponds to a two-dimensional tomographic image, but a three-dimensional image may be constructed. Incidentally, in the apparatus of the present embodiment, the rotation speed of the measurement unit in the gantry 18 is, for example, 10 rotations per minute. Of course, such a rotation speed can be appropriately set according to the application.

  FIG. 2 is a block diagram showing the configuration 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.

  In FIG. 2, a high voltage source used with the X-ray generator 52, a data processing circuit used with the X-ray detector 60, and the like are not shown.

  In FIG. 2, reference numeral 58 denotes an effective field of view. This is a circular area in which a CT image can be formed when the X-ray beam 56 is rotated and scanned. Incidentally, the effective visual field 58 is determined according to the positional relationship between the X-ray generator 52 and the X-ray detector 60 and the specimen or the rotation center axis. In this embodiment, since the displacement mechanism 62 is provided, it is possible to change the positional relationship between them and mechanically vary the magnification of the CT image.

  That is, the X-ray generator 52 and the X-ray detector 60 are connected to the displacement mechanism 62, and the displacement mechanism 62 maintains the distance between the X-ray generator 52 and the X-ray detector 60. (That is, the measurement unit) has a function of displacing in the beam axis direction of the X-ray beam 56. In this case, the rotation center axis O is not changed, that is, the magnification can be changed by moving the measurement unit without moving the container described above. The displacement mechanism 62 includes a motor 62A for generating a displacement force.

  The gantry rotation mechanism 66 is a mechanism that rotates the entire base including the displacement mechanism mounted thereon by rotating the rotation base. Since the measurement unit is mounted on the displacement mechanism 62, the measurement unit positioned at a desired position by the displacement mechanism 62 is rotationally driven while maintaining the position. The gantry rotating mechanism 66 has a motor 66A for generating the driving force.

  The slide mechanism 68 is a moving mechanism that slides the arm 26 shown in FIG. 1, and the driving force is generated by the motor 68A. The operation panel 20 is provided on the upper surface of the main body as described above. The operation panel 20 may be connected to a local controller (not shown) provided on the measurement unit 10 side so that the local controller and the arithmetic control unit 12 communicate with each other.

  Incidentally, although various mechanisms 62, 66, 68, etc. are shown in FIG. 2, it is desirable to provide a sensor to detect a position or a change by these mechanisms. Then, it is desirable that the arithmetic control unit 12 performs so-called feedback control based on the output signals of those sensors. The magnification change by the displacement mechanism 62 may be performed by user input. For example, the subject size or the container size is automatically detected, and the magnification is automatically set based on the detected data. Also good. Furthermore, when the container type or the like is registered in advance, the magnification may be set using the registered information. Further, in the example shown in FIG. 2, the slide mechanism 68 has the motor 68A as a drive source, but the slide force may be generated artificially.

  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, the printer 40, and the like are connected to the processor 30. In addition, a communication unit 42 for communicating with an external device via a network is connected.

  The processor 30 includes a CPU and various programs. FIG. 2 shows typical functions. The processor 30 includes an operation control unit 44, a reconstruction calculation unit 46, a scout image forming unit 200, a section setting unit 202, and a data management / processing unit 204. ing.

  The operation control unit 44 controls the overall operation of the measurement unit 10. The reconstruction calculation unit 46 executes a calculation for forming a CT image based on a lot of data obtained by rotational scanning of the X-ray beam. In this case, a three-dimensional image may be constructed. Various known methods can be used for the reconstruction operation. Note that, in changing the magnification described above, the arithmetic expression used in the reconstruction calculation can be basically used as it is. However, when a special variable magnification method is applied, a part of the reconstruction calculation expression may be changed as necessary.

  The scout image forming unit 200 forms a scout image prior to the CT measurement. Specifically, the container containing a plurality of specimens is moved and scanned by the slide mechanism 68 without rotating the measurement unit 10, and X-ray measurement is performed by the measurement unit 10 at that time. Based on the detection data thus obtained, a scout image as a two-dimensional transmission image such as an X-ray photograph is formed. This scout image is formed in order to set a section for defining a CT scan range for each specimen. Further, as will be described later, it is formed to acquire specimen identification information.

  The section setting unit 202 sets a CT scan range (CT measurement range) for each specimen in the rotation center axis direction according to user settings or automatically. If only one specimen is contained in the container, the CT scan range is set so as to include it, and if multiple specimens are contained in the container, each specimen is included so as to be included. Thus, a CT scan range is set. When the range is set by the user, a scout image is displayed on the display 32, and a section for performing CT scan for each specimen is set on the scout image using the mouse 38 by visual judgment. In the case of automatic setting, both ends of each specimen are individually recognized by image processing (for example, edge detection method) of the scout image, and the interval for performing the CT scan so as to cover all or the main part of each specimen is automatically set. Is set. In any case, a CT scan range is set by the section setting unit 202, and the operation control unit 44 performs operation control during CT measurement according to the setting.

  In addition, according to the above section setting, measurement can be skipped for the CT scan unnecessary range between samples, and the measurement time for a plurality of samples as a whole can be shortened, which is efficient. Instead of setting the section, a large number of CT images may be acquired for the entire container, and unnecessary CT images may be removed automatically or by user designation.

  The data management / processing unit 204 has a function of reading the identification code of the specimen based on the scout image, a function of managing the identification code in association with the CT image formed by the reconstruction calculation unit 46, each CT image, or a specific A function of performing image processing on the CT image;

  In the present embodiment, a sample identification tool is mounted for each sample, as will be described later with a specific example. Specifically, the specimen identifying tool is configured as a cylindrical or ring-shaped member that passes through the tail of a small animal. The sample identifying tool represents a bit string composed of a plurality of (for example, 8) bits, and each bit has a value of 1 or 0. The bit string corresponds to a specimen identification code. However, in the present embodiment, the first bit is used to specify the reference position of the specimen identifying tool. On the scout image, the identification code of the sample identification tool is analyzed by image processing, and the identification code is read by this.

  CT measurement is performed on the specimen after reading the identification code based on the scout image, and a plurality of CT images (tomographic images) obtained for the specimen are managed in association with the identification code read as described above. The When a plurality of samples are accommodated in the container, the identification code is read for each sample, and the identification code of the sample is associated with the plurality of CT images for each sample. On the storage device 34, a plurality of CT images (or a plurality of images after image processing thereof) associated with the specimen identification code are stored.

  A scout image and a CT image are displayed on the display 32. For example, when displaying a CT image, it is desirable to display a numerical value representing a magnification (enlargement ratio) or a scale. According to this configuration, the size of the object can be evaluated when the image is visually determined. That is, for example, the amount of fat and the size of a tumor can be determined quantitatively. The identification code read as described above may be displayed on the screen when the scout image is displayed or during CT measurement.

  FIG. 3 schematically shows a state in which a specimen 300 as a small animal is stored in the container 24 shown in FIG. A sample identification tool 302 is provided at the tail of the sample 300. In the example shown in FIG. 3, the sample identification tool 302 includes one or more metal rings 304 arranged in the axial direction of the tail. In the present embodiment, the specimen identification tool 302 represents an 8-bit bit string, and the first bit is 1 among them. That is, the metal ring 304 is always disposed at that position. Based on the position of the leading metal ring 304, seven bit positions from the second bit to the eighth bit, that is, coordinates are specified. In the example of FIG. 3, the specimen identification tool 302 is configured by three metal rings 304, and no special member is provided in the gap between the rings. However, if that portion is an air layer, the distance between the metal rings Therefore, it is desirable to arrange a spacer ring representing bit 0 made of acrylic or the like. That is, the metal ring represents bit 1, the spacer ring represents bit 0, and the identification code is expressed by the arrangement of the metal ring and the acrylic ring. The number of bits constituting the bit string is not limited to that shown in FIG. 3, but may be 7 bits or less, or 9 bits or more.

4 shows the metal ring 304 shown in FIG. 3 as a perspective view. Incidentally, the above spacer ring has the same form as the metal ring 304. The outer diameter r ₁ of the metal ring is, for example, 8 mm, and the inner diameter r ₂ is, for example, 5 mm. The thickness D is, for example, 0.6 mm. Incidentally, one pixel size of a scout image to be described later is 0.2 mm, and in this embodiment, a thickness D that is three times the size is set.

  The metal ring 304 and the spacer ring may be attached to the tail of a small animal using, for example, an adhesive member, or may be attached using a crimping process. Further, the metal ring 304 and the spacer ring may be prevented from falling off by using a fastener. Various methods can be used for the attachment, and methods other than those described above, for example, a method of winding an adhesive tape, attaching with a string, or performing punching can be used. Incidentally, the specimen identification tool is composed of one or a plurality of metal rings and one or a plurality of spacer rings, but may be integrally formed in a state in which they are arranged. In this case, a cylindrical sample identification tool is configured in which rings corresponding to the respective bits are inseparably integrated. In addition, the sample number and the identification code can be expressed by symbols or numbers so that a human can visually read the identification code with respect to the sample identification tool. For example, it is desirable to attach the specimen identification tool in advance to a small animal for which an animal experiment is performed, but, of course, it can be attached at a stage before CT measurement is performed.

  In the present embodiment, the specimen identification tool is attached to the tail of the small animal, that is, the attachment of the specimen can be performed by inserting the tail of the small animal through the central hole of the specimen identification tool, so that positioning and arrangement are simple. There is an advantage that it is difficult to drop off. In addition, since the tail itself is generally not subject to CT measurement, there is an advantage that it does not hinder measurement. Of course, the sample identification tool may be mounted on an ear, a limb or the like other than the tail, or may be embedded in the body.

  It is desirable to use a metal ring having a large X-ray attenuation so as to be distinguished from bone in the specimen, and is made of a metal member such as copper, brass, or iron. For example, a thickness of about 1 mm in the diameter direction is sufficient. According to such a configuration, when a scout image is formed, the amount of X-ray absorption is larger than that of a bone having a relatively large amount of X-ray absorption, so that the metal ring can be easily identified on the image. It becomes.

  On the other hand, the spacer ring is preferably made of a material having an X-ray absorption equivalent to that of the air layer or soft tissue as described above, and examples of the material include acrylic. In any case, it is desirable to determine each material so that a significant difference in X-ray absorption occurs between the metal ring and the spacer ring.

  In the present embodiment, since the sample identifying tool is configured in a ring shape or a cylindrical shape, even if the sample identifying tool rotates around the center axis of the tail, the image of the sample identifying tool is not changed on the scout image, and therefore There is an advantage that the identification code can be read accurately. Incidentally, it is desirable that the specimen discriminator is placed in the container so that the center axis of the specimen identification tool matches the center axis of the container, that is, the tail of the small animal is straightened. However, if the central axis of the sample identification tool can be individually recognized in the image processing described later, the identification code can be read from the sample identification tool regardless of the orientation of the tail. In general, the root of the tail (that is, the butt side) is considered to be substantially parallel to the central axis of the container. Therefore, it is desirable to mount the specimen identification tool near the root of the tail. However, as long as the identification code can be properly read, the sample identification tool can be attached to the tip of the tail.

  FIG. 5 shows two examples of the specimen identification code. In each example, the first bit corresponds to the start bit, and the metal ring is always provided at that position. Of course, a plurality of bits may be used for recognizing the reference position, and a configuration other than the first bit may be employed as long as the reference position can be recognized.

  Seven bits following the first bit correspond to the actual identification code 308. For example, the specimen number is specified by the 7 bits. In the example shown in (A), the sample number is 20. In the case of (B), the sample number is 125. That is, if the identification code is composed of 7 bits, 128 specimens can be distinguished from each other. Therefore, if it is desired to distinguish more samples, the number of bits may be increased.

  The bit string may further include error detection and error correction including a parity bit. In this embodiment, the bit string is configured in the direction of the central axis of the tail. However, it is of course possible to extend the specimen identification tool in the orthogonal direction and arrange the bit string in the direction.

  FIG. 6 shows a scout image 310 acquired when only one specimen is stored in the container. This scout image is acquired by moving and scanning the container in the direction of its central axis without rotating and scanning the X-rays. On the scout image 310, reference numeral 312 indicates a processing range in the X-axis direction, and reference numeral 314 indicates a processing range in the Y direction. That is, the processing area is defined by these ranges. Such a range can be set by the user or can be set automatically. As will be described later, a scan line 316 is set along the Y direction at a certain X coordinate, and the presence or absence of the metal ring is determined by comparing the maximum pixel value on the line with a predetermined threshold value T. Incidentally, reference numeral 302A in FIG. 6 indicates an image of the specimen identification tool, and reference numeral 304A indicates an image of the metal ring.

  The reading of the identification code will be described with reference to the flowchart shown in FIG.

  First, in S101, a scout image is acquired for the sample by moving the container. In S102, the initial value 0 is substituted for X. In S103, the pixel value is scanned along the Y direction at the currently set X coordinate, and the maximum pixel value is specified. Then, it is determined whether or not the maximum pixel value is equal to or greater than a predetermined threshold value T. If the condition exceeding the threshold value T is not satisfied, X is incremented by 1 in S104, and the process of S103 is executed again. That is, the start bit is detected by such a process. Incidentally, in order to improve the determination accuracy, the detection of the start bit may be considered under the condition that a predetermined number or more of pixels equal to or greater than the threshold value T are continuously present.

  When the start bit is detected, 3 is added to the value of X in S105. That is, the next bit reading coordinate is specified. Here, 3 is added because, as described above, the size of one pixel in the scout image is 0.2 mm in the present embodiment, and the horizontal width of the metal ring is 0.6 mm on the other side. This is because the coordinates need only be shifted by 3 pixels. Of course, since it is desirable to read at the center of the metal ring, 4 or 5 may be added instead of 3 at the first addition.

  In S106, the pixel value is scanned along the Y direction at the X coordinate specified in S105, and the maximum pixel value is specified among them. Whether the value of the bit at the bit position is 1 or 0 is detected depending on whether the maximum pixel value is T or more. Incidentally, in S106, it is possible to omit scanning in the Y direction by using the Y coordinate of the maximum pixel value determined in S103.

  In S107, it is determined whether or not the detection for all the bits has been completed. If the detection has not been completed, each step after S105 is repeatedly executed. That is, the identification code is read by such a process.

  In S108, the read bit string is converted into an expression form that can be easily recognized by the user. Here, conversion into an identifier composed of a decimal specimen number or a character, a symbol or the like is performed. In this case, a table to be referred to at the time of conversion may be stored on the storage unit 34 shown in FIG.

  After the identification code is read for the subject sample, CT measurement is performed by moving and scanning the container intermittently while rotating the measurement unit in S109. That is, a CT tomographic image is acquired at each X-ray coordinate. In this case, the identification information may be displayed on the screen so that the user can recognize the sample currently being measured. In S110, data management is performed using the identification information read as described above for the CT image acquired in S109 or an image obtained by processing the CT image. As a result, it is possible to give specimen identification information to each CT image without error.

  FIG. 8 shows a cylindrical specimen identifying tool 302. The sample identification tool 302 is formed by integrally forming a metal ring 304 and a spacer ring 320 in a predetermined arrangement. If both the metal ring 304 and the spacer ring 320 are made of a deformable material, the specimen identifying tool 302 can be securely attached to the tail of a small animal by crushing the specimen identifying tool 302 as a whole. Of course, the attachment may be performed using an adhesive or other members.

  FIG. 9 shows a specimen identifying tool 322 according to another embodiment. In this embodiment, the specimen identifying tool 322 is constituted by a large-diameter ring 324 and a small-diameter ring 326, which are connected in the axial direction in a predetermined pattern. When such a sample identifier is used, if a scan line 332 is set for the edge portion of the sample identifier and reading is performed for each bit coordinate on the line, a gap existing outside the small diameter portion The identification code can be read from the arrangement with the meat portion of the large diameter portion. That is, when a scout image is acquired, X-rays are extremely attenuated at the site indicated by reference numeral 330, while the X-rays pass through the part indicated by reference numeral 326 because of the air layer. The identification code is read using such an edge portion.

  FIG. 10 shows still another embodiment. The sample identification tool 340 in this embodiment has a rectangular parallelepiped shape as a whole, and a rectangular cavity for inserting the tail is formed at the center, and a through-hole for bit 0 is formed on each side surface thereof. 344 is formed. Incidentally, a portion corresponding to the bit 1 is a wall surface portion 342. Therefore, for such a specimen identifying tool 340, it is possible to read the identification code by setting the scan line 326A and reading the pixel value on that line. Incidentally, reference numeral 348 indicates a bit 1 portion, and reference numeral 349 indicates a bit 0 portion.

  In the example shown in FIG. 9, through-holes are formed in the same pattern on the left and right surfaces in addition to the upper and lower surfaces, and the same reading is performed even when the specimen identification tool 340 is rotated 90 degrees when forming a scout image. It can be performed. That is, in this case, a bit string is read on the scan line 346B.

  However, in the embodiment shown in FIG. 10, although accurate code information can be read at a constant angular interval in the circumferential direction, the code is used when the specimen identification tool 340 is rotated 45 degrees with respect to the rotation center axis. There may be cases where information cannot be read properly. On the other hand, if a ring-shaped or cylindrical sample identification tool is used, there is an advantage that the above problem can be prevented beforehand because there is no direction dependency.

  FIG. 11 shows another embodiment of the container. The container 400 has a shape extended in the movement direction indicated by reference numeral 410, and a plurality of specimens can be accommodated therein. The container 400 includes a main body 402 and a lid 404 attached to the opening 402A. Incidentally, reference numeral 408 represents a proximal end portion, and reference numeral 406 represents a distal end portion. Reference numeral 412 represents a partition wall.

  FIG. 12 conceptually shows a state in which three specimens 300 are arranged in the container shown in FIG. The above-described sample identification tool 420 is attached to the tail of each sample 300.

  FIG. 13 shows a scout image 430 including three specimens. The scan ranges 434A, 434B, and 434C are set for each specimen by the section setting described above, and the range 436 is also set for the Y direction. Then, the measurement area 432 is defined for each specimen by such a range setting in the X direction and the Y direction. Incidentally, for each of the ranges 434A, 434B, and 434C in the X direction, the tip and the tail of each sample may be specified by a method such as edge detection, and the range between them may be determined as each range. That is, each range may be automatically determined by image processing. When the process shown in FIG. 7 is executed for each measurement area, the identification code can be read for each sample. At the time of CT measurement, the identification code of the sample is associated with a plurality of CT images acquired for each sample.

  According to the above-described embodiment, in the X-ray measurement apparatus, the specimen can be identified using the X-ray measurement result. Therefore, it is not necessary to provide a special mechanism for specimen identification, and the specimen identification can be easily performed. There is an advantage that can be performed. In addition, there is an advantage that the use of the sample identification tool attached to the sample as described above can prevent the sample from being mixed. In the above embodiment, the X-ray CT apparatus has been described. However, in the X-ray apparatus, the bone density measuring apparatus, etc., it is possible to attach the same specimen identifying tool to each specimen and perform specimen identification based on the X-ray imaging result. It is.

It is a perspective view which shows the whole structure of a X-ray CT apparatus. It is a block diagram which shows each structure of a X-ray CT apparatus. It is a figure for demonstrating the sample identification tool attached to the sample as a small animal. It is a perspective view of a metal ring. It is a figure which shows two examples of a sample identification code. It is a figure which shows the scout image about a sample. It is a flowchart for demonstrating the reading process of an identification code. It is a figure which shows the sample identification tool which concerns on other embodiment. It is a figure which shows the sample identification tool using a large diameter ring and a small diameter ring. It is a figure which shows the rectangular parallelepiped sample identification tool which has a through-hole. It is a perspective view which shows the container which can accommodate a some test substance. It is a schematic diagram which shows three specimens accommodated in the container. It is a figure which shows the scout image about three specimens.

Explanation of symbols

  24 containers, 300 specimens (small animals), 302 specimen identifiers, 304 metal rings.

Claims (11)

An X-ray measuring apparatus as an X-ray CT apparatus,
A sample identification tool provided on a sample as a small animal and having a sample identification code;
X-ray measuring means for irradiating the specimen with X-rays and detecting X-rays transmitted through the specimen;
Image forming means for forming a specimen image based on the X-ray detection data;
Code reading means for reading the sample identification code from an image portion of the sample identification tool included in the sample image;
A tomographic image forming means for forming a CT tomographic image of the small animal based on the X-ray detection data;
Means for managing the CT tomographic image using the read specimen identification code;
An X-ray measurement apparatus comprising: The apparatus of claim 1.
The X-ray measurement apparatus, wherein the specimen identification code is expressed using a difference in X-ray attenuation. The apparatus of claim 2.
The specimen identification code is configured as a bit string composed of a plurality of bits,
Each bit constituting the bit string is constituted by a first element or a second element having different X-ray attenuation amounts. The apparatus of claim 3.
The first element is constituted by a first member having an X-ray attenuation greater than the X-ray attenuation of bone contained in the specimen,
The X-ray measurement apparatus, wherein the second element is constituted by a second member or an air layer having an X-ray attenuation amount smaller than that of the first member. The apparatus of claim 1.
The X-ray measurement apparatus is characterized in that the sample identification tool is mounted on an outer surface of the sample or embedded in the sample. The apparatus of claim 1.
Before SL specimen identification device X-ray measuring apparatus characterized by having an insertion hole for inserting the tail of the small animal. The apparatus of claim 1.
The code reading means includes
Reference coordinate detection means for detecting reference coordinates for an image portion of the sample identification tool on the sample image;
Bit coordinate specifying means for specifying bit coordinates of each bit constituting the specimen identification code with reference to the reference coordinates;
Pixel value analysis means for reading the specimen identification code by performing pixel value analysis at the bit coordinates of each bit;
An X-ray measurement apparatus comprising: The apparatus of claim 7.
The pixel value analyzing means includes
Means for performing a scanning process on the bit coordinates of each bit to identify a maximum pixel value;
Means for determining a bit value based on the maximum pixel value;
An X-ray measurement apparatus comprising: The apparatus of claim 1.
An X-ray measurement apparatus comprising: means for managing a measurement result obtained for the specimen in association with a specimen identification code of the specimen. A specimen identification tool provided in a small animal as a specimen and having a specimen identification code;
X-ray measuring means for irradiating the small animals with X-rays and detecting X-rays transmitted through the small animals;
A scout image forming means for forming a scout image based on the X-ray detection data;
Code reading means for reading the sample identification code from the image portion of the sample identification tool included in the scout image;
A tomographic image forming means for forming a CT tomographic image of the small animal based on the X-ray detection data;
Means for managing the CT tomographic image using the read specimen identification code;
X-ray CT apparatus characterized by including. The specimen identifying tool used in the X-ray CT apparatus according to claim 10,
The sample identifier has a sample identification code composed of a plurality of bits ,
Each bit is composed of a first element or a second element having different X-ray attenuation amounts,
The first element is composed of a first member having an X-ray attenuation greater than the bone of the specimen,
The specimen identifying tool for an X-ray CT apparatus , wherein the second element is configured as a second member or an air layer that has a smaller amount of X-ray attenuation than the soft tissue of the specimen.

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