JP2014166211A - Trabecula analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trabecula analysis device capable of performing accurate temporal observation of a trabecula.SOLUTION: A purpose of a trabecula analysis device 1 is to analyze temporal change in a trabecula by performing a new trabecula analysis on an analyte M on which a trabecula analysis has been performed previously. For this purpose to be securely achieved, the trabecula analysis device 1 has a configuration in which trabecula analysis is performed on an oblique image Obl that is a tomographic image on the same plane as a cut surface of a tomographic image analyzed in the previous trabecula analysis. Thereby, a cross section to be analyzed in the current analysis can be made to correspond to a cross section analyzed in the last analysis, even when a position of a bone of the analyte M in the current trabecula analysis changes in such a way as to rotate with respect to a device from that in the last trabecula analysis. The trabecula analysis device 1 capable of accurately obtaining temporal change in the bone can be thus provided.

Description

  The present invention relates to a trabecular analyzer for analyzing a trabecular bone of a subject, and more particularly to a trabecular analyzer for executing a trabecular analysis by acquiring a radiographic image of a subject and analyzing the radiographic image.

  A trabecular bone is an elongated structure that forms the sponge within the bone. Knowing whether the trabecular bone is solid inside the bone makes it possible to diagnose the health of the subject M and diagnose the disease. Further, by analyzing the trabecular bone of the subject M, the bone strength of the subject M can also be known (see, for example, Patent Document 1).

  A conventional trabecular analysis method will be described. As shown in FIG. 16, the conventional trabecular bone analyzer 50 includes a top plate 52 on which the subject M is placed, a radiation source 53 provided above the top plate 52, and a lower side of the top plate 52. The detector 54 provided is provided. In order to perform trabecular analysis, tomography is performed using an apparatus as shown in FIG. 16, and trabecular analysis is performed on the acquired tomographic image.

  A specific method of trabecular analysis in the conventional configuration will be described. According to the conventional configuration, the tomographic image of the subject M is acquired by performing imaging while moving the radiation source 53 and the detector 54 relative to the subject M prior to the trabecular analysis. Then, the analysis of the trabecular bone reflected in the acquired tomographic image is executed.

JP 2006-517433 A

However, the conventional configuration as described above has the following problems.
That is, the conventional trabecular bone analyzer has a problem that it is difficult to accurately know changes in bone over time.

  Treatments such as osteoporosis require a long time. Therefore, in order to treat osteoporosis and the like, the effect of treatment such as medication must be observed over a long period of time. That is, it is necessary to observe how the trabecular bone of the subject M changes by repeating the trabecular analysis every several months.

  In order to accurately observe the trabecula over time, it is necessary to perform trabecular analysis on a predetermined cut surface in the bone of the subject M. That is, the cut surface when performing the trabecular analysis needs to coincide with the cut surface when performing the previous trabecular analysis. This is because if the cut surface changes each time the trabecular analysis is performed, the same part of the bone is not observed, and the trabecular bone cannot be accurately observed over time.

  In order to make the cut surface constant throughout the observation of the trabecular bone, it seems that it is only necessary to translate the cut surface to match the cut surface according to the previous analysis. However, with this method, it is difficult to make the cut surface constant. This is because the posture of the subject M is slightly different every time imaging is performed.

  In order to image the subject M, the subject M is placed on the top board. At this time, the positional relationship between the bone of the subject M and the top plate is different every time imaging is performed. In particular, when the bone of the subject M rotates and shifts with respect to the top plate between the previous imaging and the current imaging, it is quite difficult to make the cut surface constant. This is because the conventional apparatus can only generate a tomographic image of a certain plane.

  In other words, when the bone of the subject M is moved so as to rotate with respect to the top plate between the previous diagnosis and the current diagnosis, in order to accurately know the temporal change of the trabecular bone, the cutting according to the previous diagnosis is performed. The cross section must be rotated in accordance with the rotation of the bone. However, according to the conventional apparatus, it is not configured to rotate the cut surface at every photographing.

  Therefore, in the conventional apparatus, the cut surface of the tomographic image cannot be matched between the previous diagnosis and the current diagnosis, and the temporal observation of the trabecular bone cannot be made accurate.

  The present invention has been made in view of such circumstances, and provides a trabecular analysis device capable of accurately observing a trabecular bone over time in a trabecular analysis device that performs trabecular analysis of a tomographic image. It is in.

The present invention has the following configuration in order to solve the above-described problems.
That is, the trabecular bone analyzer according to the present invention includes a radiation source for irradiating radiation, a radiation source moving means for moving the radiation source relative to the subject, a radiation source movement control means for controlling the radiation source moving means, A detection means for detecting radiation that has passed through the specimen, a detector movement means for moving the detection means relative to the subject, a detector movement control means for controlling the detector movement means, and an image based on the output of the detection means A tomographic image tilted by an arbitrary tilt angle with respect to the top plate on which the subject is placed based on the image generation means to be generated and images continuously taken while moving the radiation source and the detection means relative to the subject. An oblique image generation means for generating a certain oblique image and a trabecular analysis means for calculating data for quantifying the state of the trabecular bone based on the oblique image are provided.

  [Operation / Effect] The trabecular bone analysis apparatus according to the present invention can analyze temporal changes of the trabecular bone by newly performing trabecular analysis on a subject that has been subjected to trabecular analysis previously. . In the trabecular bone analysis apparatus of the present invention, the same plane as the cross section of the subject's bone in the analyzed tomographic image in which the trabecular analysis was performed at the time of the previous trabecular analysis is a cut surface because it is necessary to reliably achieve this object. An oblique image generation means for generating an oblique image that is a tomographic image is provided, and trabecular analysis is performed on the oblique image. By adopting such a configuration, the condition of trabecular analysis can be matched between the previous time and the current time.

  That is, even when the subject's bone moves so as to rotate relative to the apparatus between the previous trabecular analysis and the current trabecular analysis, according to the apparatus of the present invention, It is possible to make the cross section to be analyzed in the current analysis coincide with the cross section of the previous analysis by rotating in accordance with the rotation. As a result, a trabecular bone analyzer that can accurately know changes in bone over time can be provided.

  The trabecular bone analyzing apparatus includes tomographic image generating means for generating a plurality of tomographic images whose cut sections are parallel to each other based on the continuously shot images, and the oblique image generating means includes a plurality of tomographic images. It is more desirable to generate an oblique image that is not parallel to the tomographic image based on the image.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. If the oblique image is generated based on the plurality of tomographic images generated by the tomographic image generating means, the oblique image can be generated more reliably.

  Further, it is more preferable that the trabecular bone analyzing apparatus includes an input unit that inputs an instruction to adjust the inclination angle between the oblique image and the tomographic image generated by the oblique image generating unit.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. That is, if an input means for inputting an instruction to adjust the inclination angle between the oblique image and the tomographic image generated by the oblique image generating means is provided, the surgeon freely rotates the tomographic image to generate the oblique image. Therefore, the cut surface of the oblique image can be matched with the cut surface of the previous analysis more reliably.

  Further, in the trabecular bone analysis apparatus described above, the oblique image generation means may determine the inclination angle between the oblique image and the tomographic image based on the shape of the contour of the bone reflected in the plurality of tomographic images.

  [Operation / Effect] With this configuration, an oblique image can be automatically generated without any input from the operator. Therefore, it is possible to provide a trabecular bone analysis device in which the complexity of photographing is suppressed.

  Further, in the trabecular bone analysis apparatus described above, the trabecular bone analysis means may determine an analysis range that is a region for performing trabecular analysis on the oblique image based on the shape of the contour of the bone reflected in the plurality of tomographic images. More desirable.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. The trabecular bone analysis means does not analyze the entire bone image by determining the analysis range, which is the region for performing trabecular analysis on the oblique image, based on the shape of the bone contour reflected in the multiple tomographic images. However, trabecular analysis is possible, and a trabecular analysis device with high analysis speed can be provided.

  In the above-described trabecular bone analysis apparatus, it is more preferable that the oblique image generation means generates an oblique image by a trilinear interpolation method.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. If the oblique image generation means generates an oblique image by the trilinear interpolation method, a trabecular bone analysis apparatus having a high analysis speed can be provided.

  In the above-described trabecular bone analysis apparatus, it is more preferable that the oblique image generation means generates an oblique image by a tricubic interpolation method.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. If the oblique image generation means generates an oblique image by the tricubic interpolation method, a trabecular analysis device capable of performing a more reliable trabecular analysis can be provided.

  Further, the trabecular bone analyzing apparatus described above is an apparatus for analyzing temporal changes of the trabecular bone by newly performing trabecular analysis on a subject that has been subjected to trabecular analysis before, and an oblique image generating means It is more desirable that the oblique section of the generated oblique image is the same plane as the cross section of the subject's bone in the analyzed tomographic image that has been subjected to trabecular analysis during the previous trabecular analysis.

  [Operation / Effect] The above-described configuration shows a more specific configuration of the present invention. Since the oblique image generation means of the above-described apparatus can match the tomographic plane of the previous tomographic image and the tomographic plane of the oblique image, the trabecular bone analyzing apparatus can more reliably track the temporal change of the subject. Can be provided.

  The trabecular bone analyzer according to the present invention is intended to analyze a temporal change of a trabecular bone by newly performing a trabecular analysis on a subject for which trabecular analysis has been performed previously. The trabecular bone analysis apparatus according to the present invention cuts the same plane as the cross section of the subject's bone in the cut surface of the analyzed tomographic image that has been subjected to trabecular analysis at the time of previous trabecular analysis from the necessity of reliably achieving this object. The trabecular analysis is performed on the oblique image which is a surface. As a result, even if the subject's bone moves so as to rotate relative to the device between the previous trabecular analysis and the current trabecular analysis, the cross section to be analyzed in this analysis matches the cross section in the previous analysis Can be made. As a result, a trabecular bone analyzer that can accurately know changes in bone over time can be provided.

It is a functional block diagram explaining the whole structure of the trabecular bone analyzer which concerns on Example 1. FIG. 3 is a schematic diagram illustrating the principle of capturing a tomographic image according to Embodiment 1. FIG. It is a schematic diagram explaining the relationship between the tomographic image which concerns on Example 1, and a top plate. It is a schematic diagram explaining the relationship between the oblique image and the top plate according to the first embodiment. 6 is a schematic diagram illustrating a pixel interpolation method according to Embodiment 1. FIG. 3 is a schematic diagram illustrating a trilinear interpolation method according to Embodiment 1. FIG. It is a schematic diagram explaining the tricubic interpolation method according to the first embodiment. FIG. 10 is a schematic diagram for explaining an oblique image generation method according to the first embodiment. FIG. 6 is a schematic diagram for explaining the operation of the trabecular bone analysis unit according to the first embodiment. It is a flowchart explaining operation | movement of the trabecular bone analysis apparatus of Example 1. FIG. FIG. 10 is a schematic diagram for explaining the operation of the trabecular bone analyzer according to the second embodiment. FIG. 10 is a schematic diagram illustrating the principle of capturing a tomographic image according to the second embodiment. FIG. 10 is a schematic diagram illustrating the principle of capturing a tomographic image according to the second embodiment. FIG. 10 is a schematic diagram illustrating the principle of capturing a tomographic image according to the second embodiment. It is a mimetic diagram explaining one modification concerning the present invention. It is a functional block diagram explaining the structure of the conventional apparatus.

  Next, an embodiment of a trabecular bone analyzer according to the present invention will be described with reference to the drawings. In addition, the X-ray in an Example is corresponded to the radiation of the structure of this invention. Note that FPD is an abbreviation for flat panel X-ray detector (flat panel detector).

  FIG. 1 is a functional block diagram illustrating the configuration of the trabecular bone analyzer according to the first embodiment. As shown in FIG. 1, the trabecular bone analyzer 1 according to the first embodiment includes a top plate 2 on which a subject M that is a target of X-ray tomography is placed, and an upper portion of the top plate 2 (1 of the top plate 2). X-ray tube 3 that irradiates the subject M provided on the surface side) with a cone-shaped X-ray beam, and the lower part of the top plate 2 (on the other side of the top plate) and transmits the subject M. The X-ray tube 3 and the FPD 4 are placed with the region of interest of the subject M in between with the FPD 4 that detects the detected X-ray and the center axis of the cone-shaped X-ray beam and the center point of the FPD 4 always coincident with each other. An X-ray grid that absorbs scattered X-rays provided so as to cover an X-ray detection surface that detects X-rays of the FPD 4 and a synchronous movement control unit 8 that controls the synchronous movement mechanism 7 that moves synchronously in the opposite direction. And 5. In this way, the top plate 2 is disposed at a position sandwiched between the X-ray tube 3 and the FPD 4. The X-ray tube 3 corresponds to the radiation source of the present invention, and the FPD 4 corresponds to the radiation detection means of the present invention. The X-ray tube 3 corresponds to the radiation source of the present invention, and the FPD 4 corresponds to the detection means of the present invention.

  The synchronous movement mechanism 7 includes an X-ray tube movement mechanism 7a that moves the X-ray tube 3 in the body axis direction A with respect to the subject M, and an FPD movement mechanism that moves the FPD 4 in the body axis direction A with respect to the subject M. 7b. The synchronous movement control unit 8 includes an X-ray tube movement control unit 8a that controls the X-ray tube movement mechanism 7a and an FPD movement control unit 8b that controls the FPD movement mechanism 7b. The X-ray tube moving mechanism 7a corresponds to the radiation source moving means of the present invention, and the FPD moving mechanism 7b corresponds to the detector moving means of the present invention. The X-ray tube movement control unit 8a corresponds to the radiation source movement control unit of the present invention, and the FPD movement control unit 8b corresponds to the detector movement control unit of the present invention.

  The X-ray tube 3 is configured to repeatedly irradiate the subject M with a cone-shaped and pulsed X-ray beam according to the control of the X-ray tube control unit 6. The X-ray tube 3 is provided with a collimator that collimates the X-ray beam into a cone shape that is a pyramid. The X-ray tube 3 and the FPD 4 generate imaging systems 3 and 4 that capture an X-ray transmission image.

  The synchronous movement mechanism 7 is configured to move the X-ray tube 3 and the FPD 4 in synchronization. The synchronous movement mechanism 7 linearly moves the X-ray tube 3 along a linear trajectory (longitudinal direction of the top 2) parallel to the body axis direction A of the subject M according to the control of the synchronous movement control unit 8. The moving direction of the X-ray tube 3 and the FPD 4 coincides with the longitudinal direction of the top 2. Moreover, during the examination, the cone-shaped X-ray beam irradiated by the X-ray tube 3 is always irradiated toward the region of interest of the subject M. The X-ray irradiation angle is determined by the X-ray tube 3. Is changed from, for example, an initial angle of −20 ° to a final angle of 20 °. Such an X-ray irradiation angle change is performed by the X-ray tube tilting mechanism 9. The X-ray tube tilt control unit 10 is provided for the purpose of controlling the X-ray tube tilt mechanism 9.

  The trabecular bone analyzer 1 according to the first embodiment further includes a main control unit 25 that comprehensively controls the control units 6, 8, and 10 and a display unit 27 that displays the tomographic image D. The main control unit 25 is constituted by a CPU, and realizes the control units 6, 8, 10 and the later-described units 11, 12, 13, 14 by executing various programs. The storage unit 23 stores all data related to the control of the trabecular bone analyzer 1 such as parameters related to the control of the X-ray tube 3. The console 26 allows the operator to input each operation on the trabecular bone analyzer 1. The console 26 corresponds to input means of the present invention.

  Further, the synchronous movement mechanism 7 synchronizes with the linear movement of the X-ray tube 3 described above, and causes the FPD 4 provided at the lower part of the top 2 to move in the body axis direction A (the longitudinal direction of the top 2) of the subject M. Move straight ahead. The moving direction is opposite to the moving direction of the X-ray tube 3. In other words, a cone-shaped X-ray beam whose focal position and irradiation direction change as the X-ray tube 3 moves is always received by the entire surface of the X-ray detection surface of the FPD 4. Yes. Thus, in one inspection, the FPD 4 acquires, for example, 74 fluoroscopic images P0 while moving in synchronization with the X-ray tube 3 in the opposite directions. Specifically, the imaging systems 3 and 4 are opposed to the position indicated by the alternate long and short dash line illustrated in FIG. 1 through the position indicated by the broken line with the position of the solid line as the initial position. That is, a plurality of X-ray transmission images are taken while changing the positions of the X-ray tube 3 and the FPD 4. By the way, since the cone-shaped X-ray beam is always received by the entire surface of the X-ray detection surface of the FPD 4, the central axis of the cone-shaped X-ray beam during imaging always coincides with the center point of the FPD 4. During imaging, the center of the FPD 4 moves straight, but this movement is in the direction opposite to the movement of the X-ray tube 3. That is, the X-ray tube 3 and the FPD 4 are moved in the body axis direction A synchronously and in directions opposite to each other. A symbol S in FIG. 1 represents the body side direction of the subject M.

  That is, the synchronous movement mechanism 7 moves the FPD 4 toward the other end side in the longitudinal direction of the top plate 2 in synchronization with moving the X-ray tube 3 toward one end side in the longitudinal direction of the top plate 2. Behaves properly.

  Further, an image generation unit 11 that generates a fluoroscopic image P0 based on a detection signal output from the FPD 4 is provided (see FIG. 1), and further downstream of the image generation unit 11 is provided. And a tomographic image generation unit 12 that generates a tomographic image D by synthesizing the fluoroscopic image P0. The image generation unit 11 corresponds to the image generation unit of the present invention, and the tomographic image generation unit 12 corresponds to the tomographic image generation unit of the present invention.

  Next, the principle of acquiring a tomographic image of the trabecular bone analyzer 1 according to the first embodiment will be described. FIG. 2 is a diagram illustrating a tomographic image acquisition method of the X-ray imaging apparatus according to the first embodiment. For example, a virtual plane (reference cut section MA) parallel to the top plate 2 (horizontal with respect to the vertical direction) will be described. As shown in FIG. The FPD 4 is synchronized with the opposite direction of the X-ray tube 3 in accordance with the irradiation direction of the cone-shaped X-ray beam B by the X-ray tube 3 so as to be projected onto the fixed points p and q of the X-ray detection surface of the FPD 4. A series of perspective images P <b> 0 are generated by the image generation unit 11 while being moved. In the series of fluoroscopic images P0, the projected image of the subject M is reflected while changing the position. Then, when this series of fluoroscopic images P0 is reconstructed by the tomographic image generation unit 12, images (for example, fixed points p and q) located on the reference cut surface MA are accumulated and imaged as an X-ray tomographic image. It will be. On the other hand, the point I that is not located on the reference cut surface MA is reflected as a point i in a series of subject images while changing the projection position on the FPD 4. Unlike the fixed points p and q, such a point i is blurred without forming an image when the tomographic image generation unit 12 superimposes the X-ray transmission images. In this way, by superimposing a series of fluoroscopic images P0, an X-ray tomographic image in which only an image located on the reference cut surface MA of the subject M is reflected is obtained. In this way, when the perspective image P0 is simply superimposed, a tomographic image D at the reference cut surface MA is obtained.

  Further, by changing the setting of the tomographic image generation unit 12, a similar tomographic image can be obtained even at an arbitrary cut surface horizontal to the reference cut surface MA. During shooting, the projection position of the point i moves in the FPD 4, but this moving speed increases as the separation distance between the point I before projection and the reference cut surface MA increases. If this is used to reconstruct a series of acquired subject images while shifting the body image in the body axis direction A at a predetermined pitch, a tomographic image D at a cutting plane parallel to the reference cutting plane MA is obtained. It is done. Such a series of subject image reconstruction is performed by the tomographic image generation unit 12.

  A practical operation of the tomographic image generation unit 12 will be described. The tomographic image generation unit 12 receives a fluoroscopic image P0 continuously taken while moving the X-ray tube 3 and the FPD 4 with respect to the subject M from the image generation unit 11. The tomographic image generation unit 12 generates a plurality of tomographic images D having a cut surface parallel to the reference cut surface MA based on the series of fluoroscopic images P0. The cut surfaces of the generated tomographic image D are parallel to each other as shown in FIG. The set of a plurality of tomographic images D acquired at this time can also be regarded as a three-dimensional image of the subject M that three-dimensionally represents the structure inside the subject.

  A plurality of tomographic images D generated by the tomographic image generating unit 12 are sent to the oblique image generating unit 13. The oblique image generation unit 13 generates an oblique image Obl based on the plurality of tomographic images D. The oblique image Ob1 will be described. The oblique image Obl is a tomographic image when the subject M is cut along a certain cut surface. The difference between the oblique image Obl and the tomographic image D that appeared earlier is that the cut surface of the oblique image Obl is not parallel to the cut surface of the top plate 2 and the tomographic image D, as shown in FIG. . Such an oblique image Obl is a tomographic image inclined by an arbitrary inclination angle with respect to the top 2 and is obtained by performing interpolation processing on a plurality of tomographic images D. The oblique image generation unit 13 corresponds to the oblique image generation means of the present invention.

  FIG. 5 shows how the oblique image generation unit 13 generates an oblique image Obl from a plurality of tomographic images D. The oblique image generation unit 13 first recognizes the positional relationship between the cut surface of the oblique image Obl to be generated and the tomographic image D. How to determine the cut surface of the oblique image Obl will be described later.

  The oblique image generation unit 13 pays attention to the intersection point p between the oblique image Ob1 and each tomographic image D shown in FIG. This portion is a portion where the pixel value is known in the oblique image Obl to be generated. That is, the pixel value of the pixel at the intersection point p on the oblique image Obl is directly equal to the pixel value of the pixel at the same position in the tomographic image D.

  However, the oblique image Obl cannot be generated only with the pixel value on the intersection point p. This is because the pixels on the intersection point p occupy only a part of the oblique image Obl. Specifically, the distribution of the intersection points p in the oblique image Ob1 is arranged with a certain rule as shown by the hatched portion in FIG. Now, the plane in which the oblique image Ob1 is parallel to the top 2 is defined as the plane rotated about the central axis extending in the short direction of the top 2. Therefore, the intersection point p in the oblique image Ob1 is located at the position indicated by the oblique line in FIG. 6 and is distributed in a stripe shape as viewed in the entire oblique image Obl.

  Therefore, the oblique image generation unit 13 performs pixel value interpolation on the oblique image Obl in which the pixel value is not yet partially set, and completes the oblique image Obl. Specifically, the oblique image generation unit 13 determines the pixel value of a pixel whose pixel value is undetermined by estimating the pixel value. Then, the oblique image generation unit 13 interpolates the pixel value of the pixel a by arranging the pixel value obtained by interpolation at the position of the pixel a of the oblique image Ob1 shown in FIG. 6, for example. This operation is repeatedly executed until a pixel whose pixel value is unknown from the oblique image Ob1 being generated disappears.

  A state in which the pixel a in FIG. 6 is interpolated by the oblique image generation unit 13 will be described. First, the oblique image generation unit 13 sets a region to be used for the interpolation processing as indicated by the thick frame in FIG. This area is set so as to include eight pixels surrounding the pixel a. Therefore, the area is a rectangular area of 3 × 3 with the pixel a at the center.

  Next, the oblique image generation unit 13 estimates the pixel value of the pixel a by weighting the pixel values of the eight pixels surrounding the pixel a. This weighting is changed according to the distance between the pixel a and the target pixel to be weighted. That is, the pixel value is weighted so as to be lighter as the distance between the pixel a and the target pixel becomes longer, and the pixel value is weighted so as to become heavier as the distance between the pixel a and the target pixel becomes shorter. The pixel value of the pixel a should be closer to the pixel value of the pixel at a position closer than the pixel value of the pixel far from the pixel a. That is, the pixel value of the pixel a should be closer to the pixel value of the pixel adjacent in the horizontal direction from the pixel value of the pixel located diagonally from the pixel a among the eight pixels surrounding the pixel a. . The oblique image generation unit 13 performs weighting in response to such a situation.

  The oblique image generation unit 13 estimates the average value after the weighting process as the pixel value of the pixel a. Therefore, if the eight pixels surrounding the pixel a are at the same distance from the pixel a, weighting is not performed, and the oblique image generation unit 13 simply averages the pixel values of the eight pixels to obtain the pixel value of the pixel a. Will be estimated. Such a pixel estimation method is called a trilinear interpolation method.

  According to the description of FIG. 6, the area for obtaining the pixel a is as large as 3 × 3 pixels, but the area may be as large as 5 × 5 pixels. In either case, the pixel a is located at the center of the region.

  If the oblique image generation unit 13 generates the oblique image Obl by the trilinear interpolation method, the analysis speed can be increased.

<Another interpolation method performed by the oblique image generation unit>
Next, another interpolation method performed by the oblique image generation unit 13 will be described. That is, the oblique image generation unit 13 does not necessarily generate the oblique image Obl according to the trilinear interpolation method.

  The generation method of the oblique image Obl described below is a method called a tricubic interpolation method. First, the plurality of tomographic images D generated by the tomographic image generation unit 12 can be viewed as capturing the subject image in three dimensions. The oblique image generation unit 13 uses this to three-dimensionally grasp a pixel close to the pixel a to be interpolated, and estimates the pixel value of the pixel a from these pixel values.

  FIG. 7 illustrates an area used by the oblique image generation unit 13 for interpolation processing of the pixel value of the pixel a. This area is set so as to include 26 pixels surrounding the pixel a. Therefore, the region is a cubic region of 3 × vertical × 3 × height. The tricubic interpolation method is basically the same as the trilinear interpolation method except that the number of pixels that are considered to be close to the pixel a is increased as compared to the trilinear interpolation method. Therefore, the oblique image generation unit 13 weights the pixel values of the 26 pixels according to the distance from the pixel a, and then obtains an average of the values after the weighting process to estimate the pixel value of the pixel a. .

  According to the description of FIG. 7, the area for obtaining the pixel a is as large as 3 × 3 × 3 pixels, but the area may be as large as 5 × 5 × 5 pixels. In either case, the pixel a is located at the center of the region.

  If the oblique image generation unit 13 generates the oblique image Obl by the tricubic interpolation method, a more reliable trabecular analysis can be performed.

<Recognition of the cut surface performed by the oblique image generation unit>
How the oblique image generation unit 13 recognizes the cut surface of the oblique image Obl before generating the oblique image Obl will be described. The trabecular bone analyzer 1 according to the first embodiment extends from the initial state in which the oblique image Ob1 is parallel to the top plate 2 to the left side in FIG. If it can be set by rotating about a rotation axis (top plate short direction axis) on the surface, as shown in the center of FIG. 8, the rotation shaft extends in the longitudinal direction of the top plate 2 and is on the cut surface. It can also be set by rotating around (the top plate longitudinal axis). Further, the trabecular bone analyzer 1 according to the first embodiment, as shown on the right side of FIG. 8 from the initial state where the oblique image Ob1 is parallel to the top plate 2, is orthogonal to the top plate 2 and is cut. It can also be set by rotating around a rotation axis (top plate orthogonal axis) passing through the center of the surface. The center of the cut surface means the center of the image when the oblique image generation unit 13 generates the oblique image Obl. These settings are performed when the surgeon inputs a parameter of the rotation intensity through the console 26. Further, the surgeon can freely set the direction of the cut surface by combining the rotation of the three axes. Therefore, the console 26 serves as an input unit for inputting an instruction to adjust the inclination angle between the oblique image Obl generated by the oblique image generation unit 13 and the tomographic image D.

  The setting of the rotation of the cutting plane of the surgeon's oblique image Obl is set so as to be in the same plane as the cutting plane of the tomographic image (analyzed tomographic image) subjected to the trabecular analysis at the previous trabecular analysis. That is, the surgeon sets the oblique image Obl so that the same plane as the cross section of the bone of the subject M in the analyzed tomographic image becomes the cut surface.

  Further, the oblique image generation unit 13 determines the position of the center of the cut surface (the center of the oblique image Ob1) with respect to the top plate 2 in addition to the adjustment related to the rotation described above, in the longitudinal direction, the short direction, and the top of the top plate 2. It can also be set by parallel translation in three directions orthogonal to the plate 2. These settings are performed when the surgeon inputs a parameter of the rotation intensity through the console 26. In addition, the surgeon can freely set the direction of the cut surface by combining three parallel translations. The surgeon's setting of the translation of the oblique image Obl is the same as the subject image in which the subject image reflected in the oblique image Obl is reflected in the field of view of the analyzed tomographic image related to the previous trabecular analysis. To be done.

<Operation of trabecular bone analysis unit>
The generated oblique image Ob1 is sent to the trabecular bone analysis unit 14. The trabecular bone analysis unit 14 performs various analyzes on the oblique image Obl to calculate data for quantifying the state of the trabecular bone. Each numerical value obtained at this time is used to determine a temporal change in the bone state of the subject M. Hereinafter, a quantitative operation of the trabecular bone performed by the trabecular bone analysis unit 14 will be described. The trabecular analysis unit 14 corresponds to trabecular analysis means of the present invention.

<Calculation of total trabecular length / number of trabeculae / average trabecular length>
FIG. 9 is a schematic diagram for explaining the operation of the trabecular bone analysis unit 14. The left side of FIG. 9 represents a tomographic image of the bone of the subject M shown in the oblique image Obl. The trabecular bone analysis unit 14 recognizes a part of the sponge within the bone as the analysis range R. A method for recognizing the analysis range R will be described later.

  The right side of FIG. 9 represents an enlarged view of the analysis range R. In the analysis range R, tomographic images of a plurality of trabeculae are shown. This trabecular bone forms a reticulated sponge. The trabecular bone analysis unit 14 acquires the branch point n of the trabecular bone in the analysis range R by image analysis, and obtains a line segment K connecting the branch points n. The trabecular bone analysis unit 14 adds up the lengths of these line segments K. The numerical value obtained by this is the total trabecular extension that is the total extension of the trabecular bone in the analysis range R. It can be seen that as the total length of the trabecular bone is longer, more trabecular bones exist in the analysis range R, and the bone reflected in the oblique image Ob1 is more difficult to fracture.

  Moreover, the trabecular bone analysis unit 14 counts the number of the obtained line segments K. The numerical value obtained by this is the number of trabeculae which is the number of trabeculae in the analysis range R. It can be seen that as the number of trabeculae increases, more trabecular bones exist in the analysis range R, and the bones reflected in the oblique image Ob1 are more difficult to fracture.

  Then, the trabecular bone analysis unit 14 divides the total trabecular extension by the number of trabeculae. The numerical value obtained by this is the average trabecular length which is the average of the length of the trabecular bone in the analysis range R. This average trabecular length is an index for knowing the trabecular quality of the bone reflected in the oblique image Obl. That is, even if the trabecular total length is the same, if the average trabecular length is different, the manner in which the force when an impact is applied to the bone is transmitted to the inside of the bone is different. If the average trabecular length is obtained, the difference in the physical properties of the bone can be known numerically.

<Operation of trabecular bone analyzer>
The operation of the trabecular bone analyzer 1 having the above configuration will be described with reference to FIG. In FIG. 10, first, a similar trabecular analysis is performed once again on a subject M for which trabecular analysis has been performed once using the trabecular analysis apparatus according to the first embodiment, and a temporal change of the trabecular bone is diagnosed. Is the operation of the device.

<Previous analysis step S1>
First, trabecular analysis is performed once using the trabecular bone analysis apparatus 1. This analysis is called the previous analysis. In order to perform trabecular analysis using the trabecular bone analyzer 1 according to the present invention, first, the subject M is placed on the top board 2. Then, the X-ray tube 3 and the FPD 4 are moved with respect to the subject M, and a tomographic image D is generated. The trabecular bone analysis unit 14 performs trabecular analysis for the analysis range R on the generated tomographic image D. The analysis range R may be set by the operator through the console 26, or the trabecular analysis unit 14 may estimate the position of the spongy from the shape of the bone.

  Based on the operator's instruction given through the console 26, the trabecular bone analysis unit 14 determines the positional relationship between the cut surface of the tomographic image D used for the analysis and the subject M, the range of the generated tomographic image D, and the subject. The trabecular analysis is performed by recognizing the positional relationship with M and the positional relationship of the analysis range R on the tomographic image D. The purpose of this operation is to enable the same analysis to be realized in the next trabecular analysis.

  The subsequent steps relate to the case where the trabecular analysis is performed again at a later date for the purpose of knowing the temporal change of the subject M. This analysis will be called this analysis.

<Subject placement step S2, tomographic image generation step S3>
In order to perform another trabecular analysis using the trabecular bone analyzer 1 according to the present invention, the subject M is first placed on the top 2. Then, the X-ray tube 3 and the FPD 4 are moved with respect to the subject M, and a plurality of tomographic images D are generated. The operation of this analysis so far is not much different from the operation performed in the previous analysis.

<Oblique image generation step S4>
This step is a step that was not executed in the previous analysis. That is, a plurality of generated tomographic images D are sent to the oblique image generation unit 13 to generate an oblique image Obl. The rotation of the cut surface of the oblique image Ob1 is set so that the same plane as the cross section of the bone of the subject in the tomographic image (analyzed tomographic image) subjected to trabecular analysis at the previous trabecular analysis becomes the cut surface. And the setting of the parallel movement of the cut surface of the oblique image Obl is the same as the subject image in which the subject image reflected in the oblique image Obl is reflected in the field of view of the analyzed tomographic image related to the previous trabecular analysis. Is set to be Such setting is performed by an operator's input through the console 26.

<Tibial analysis step S5>
The generated oblique image Ob1 is sent to the trabecular bone analysis unit 14. First, the trabecular analysis unit 14 sets an analysis range R for performing trabecular analysis on the oblique image Obl. At this time, the trabecular analysis unit 14 operates to perform trabecular analysis for the same region as the analysis range R used in the previous analysis. In such an operation for matching the analysis range R, the trabecular analysis unit 14 stores data indicating the positional relationship of the analysis range R on the tomographic image D when the analysis range R is set in the previous analysis. This is realized by memorizing it. That is, when setting the analysis range R in this analysis, the trabecular analysis unit 14 reads the data indicating the positional relationship stored in the storage unit 23, and sets the analysis range on the oblique image Obl accordingly. is there. Note that the image size of the tomographic image D according to the previous analysis is the same as the image size of the oblique image Ob1, and the magnification of the image reflected in each image is also the same.

  According to the configuration of the first embodiment, the position where the analysis range R in the previous trabecular analysis occupies the bone of the subject M and the position where the analysis range R in the current trabecular analysis occupies the bone of the subject M are one. I'm doing it. Therefore, when the trabecular analysis is performed, a predetermined place of the subject M is captured. That is, the trabecular pattern in the previous analysis range R and the trabecular pattern in the current analysis range R should match. However, since the trabecular bone of a living body is constantly remade, the trabecular pattern changes with time. According to the trabecular bone analysis apparatus according to the first embodiment, the same part of the bone can be observed with time, so that it is possible to reliably know how the trabecular bone in the analysis range R changes.

  Thus, in order to match the analysis range R that is the analysis target range every time the trabecular analysis is performed, by rotating the analysis range R with respect to the bone, the analysis range R becomes the analysis range R in the previous analysis. It is necessary to adjust to match. According to the configuration of the first embodiment, such an adjustment is performed by the oblique image generation unit 13. That is, the surgeon can rotate the analysis image R by following the rotation of the oblique image Obl through the oblique image generation unit 13.

  Finally, the comparison between the previous analysis result and the current analysis result is displayed on the display unit 27, and the trabecular analysis is completed.

  As described above, the trabecular bone analyzer 1 according to the present invention analyzes a temporal change of the trabecular bone by newly performing a trabecular analysis on the subject M for which the trabecular analysis has been performed previously. It is an object. The trabecular bone analyzer 1 according to the present invention has the same plane as the cross section of the subject's bone in the analyzed tomographic image that has been subjected to trabecular analysis at the time of previous trabecular analysis because of the need to reliably achieve this object. The oblique image generation unit 13 that generates an oblique image Ob1 that is a tomographic image is provided, and trabecular analysis is performed on the oblique image Obl. By adopting such a configuration, the condition of trabecular analysis can be matched between the previous time and the current time.

  That is, even when the bone of the subject M moves relative to the apparatus between the previous trabecular analysis and the current trabecular analysis, according to the apparatus of the present invention, By rotating according to the rotation of the bone, the cross section to be analyzed in the current analysis can be matched with the cross section of the previous analysis. Thereby, the trabecular bone analyzer 1 which can know the bone change with time can be provided.

  Further, as described above, if the console 26 for inputting an instruction to adjust the inclination angle between the oblique image Obl generated by the oblique image generation unit 13 and the tomographic image D generated by the tomographic image generation unit 12 is provided. Since the surgeon can freely rotate the tomographic image to generate the oblique image Obl, the cut surface of the oblique image Obl can be more reliably matched with the cut surface of the previous analysis.

  Subsequently, a trabecular bone analyzer according to Example 2 will be described. In the configuration of the second embodiment, as shown in FIG. 11, a tomographic image can be taken while the X-ray tube 3 and the FPD 4 are moved in the body axis direction A of the subject M with the mutual positional relationship maintained. It is a possible configuration. That is, the synchronous movement mechanism 7 moves the FPD 4 toward one end side in the longitudinal direction of the top plate 2 in synchronization with moving the X-ray tube 3 toward one end side in the longitudinal direction of the top plate 2. To work.

  The configuration of the X-ray imaging apparatus according to the second embodiment is the same as the functional block diagram in FIG. 1 differs from the first embodiment in that the FPD 4 moves following the X-ray tube 3 (see FIG. 11), and the X-ray tube 3 does not tilt. Therefore, in the second embodiment, the X-ray tube tilt mechanism 9 and the X-ray tube tilt control unit 10 in FIG. 1 are not necessarily required.

  The principle of tomographic image capturing according to the second embodiment will be described. First, as shown in FIG. 11, X-rays are intermittently emitted while moving with respect to the subject M in a state where the imaging systems 3 and 4 maintain the relative positions. That is, every time one irradiation is completed, the X-ray tube 3 moves in the body axis direction A of the subject M and again performs X-ray irradiation. In this way, a plurality of transmission images are acquired, and a processed image (a long transmission image described later) of the transmission image is reconstructed into a tomographic image by the filter back projection method. The completed tomographic image is an image in which a tomographic image obtained by cutting the subject M with a certain cut surface is reflected.

  In order to generate a tomographic image, an image when the subject M is seen through from different directions is required. The trabecular bone analysis device according to the second embodiment generates the image by dividing and joining the obtained transmission images. This operation will be described. FIG. 12 shows the position of the FPD 4 when the focal point for irradiating the X-ray of the X-ray tube 3 is at the position d1. In this imaging, a transmission image is captured every time the X-ray tube 3 and the FPD 4 move in this direction relative to the top 2 by a width of 1/5 of the FPD 4 in the body axis direction A of the subject M. To do.

  Since the X-ray spreads radially from the X-ray tube 3 and reaches the FPD 4, when the generated transmission image is divided into five in the body axis direction A of the subject M, the incident angle of the X-ray with respect to the FPD 4 is as shown by an arrow. The divisions are different from each other. Pay attention to one of the directions k. Since the X-rays traveling in the direction k pass through the hatched portion of the subject M and are reflected in the FPD 4, the diagonal lines of the subject M are included in the FPD 4 in which the X-rays in the direction k are incident. The part is reflected. In the transmission image, a portion corresponding to this division is defined as a fragment R1.

  FIG. 13 shows the position of the FPD 4 when the focal point for irradiating the X-rays of the X-ray tube 3 is at the position d2 moved from the distance d1 by 1/5 of the width of the FPD4. Since the positional relationship between the X-ray tube 3 and the FPD 4 does not change, the FPD 4 should also have a division in which the X-rays traveling in the direction k are reflected in the imaging at this time, and the X-rays in the direction k The hatched portion of the subject M is reflected in the divisional area of the FPD 4 on which is incident. In the transmission image, a portion corresponding to this division is referred to as a fragment R2.

  When the fragment R1 and the fragment R2 are compared, since the position of the subject M with respect to the imaging systems 3 and 4 is different, the portions of the subject M reflected in both the fragments R1 and R2 are different from each other. By shifting the X-ray tube 3 by 1/5 the width of the FPD 4, assuming that nine times of imaging were performed at the focal points d 1 to d 9, the transmitted image in the divisional section of the FPD 4 where the X-rays in the direction k were incident at that time Each fragment R1 to R9 includes a different position of the subject M. Therefore, as shown in FIG. 14, if the fragments R1 to R9 of the transmission image are connected in this order to the body axis direction A of the subject M, the image is taken when the whole body of the subject M is irradiated with X-rays in a certain direction k. Images can be obtained. This image is called a long transmission image.

  The trabecular bone analyzer according to the second embodiment generates a long transmission image in a direction other than the direction k in the tomographic image generation unit 12. The tomographic image generation unit 12 generates a tomographic image when the subject M is cut at a predetermined cutting position based on a plurality of long transmission images having different directions in which the subject M is projected.

  Since the operation of generating the oblique image Obl and the trabecular analysis according to the second embodiment are the same as the operation of the apparatus according to the first embodiment, the description thereof is omitted.

  As described above, according to the configuration of the second embodiment, a long image acquired by virtually performing slot imaging is captured, and a tomographic image D is captured from these images. By performing such imaging, it is possible to provide a radiation imaging apparatus that can acquire tomographic images captured over a wide range.

  The present invention is not limited to the above-described configuration and can be modified as follows.

  (1) Although the setting of rotation and movement of the cut surface of the oblique image Obl according to the first embodiment is manual, it may be configured to be automatic. That is, the oblique image generation unit 13 may determine the inclination angle between the oblique image Obl and the tomographic image D based on the shape of the contour of the bone reflected in the plurality of tomographic images D.

  This configuration will be specifically described. First, a plurality of tomographic images D are generated in the previous analysis. The set of a plurality of tomographic images D can also be regarded as a three-dimensional image that three-dimensionally represents the structure inside the subject. Therefore, the oblique image generation unit 13 recognizes the shape of the bone contour three-dimensionally from the set of tomographic images D. Specifically, as shown on the left side of FIG. 15, the oblique image generation unit 13 grasps the three-dimensional positional relationship between the characteristic three points pa, pb, and pc of the bone contour shape, and the three points. The positional relationship between pa, pb, pc and the analysis range R of trabecular analysis is converted into data. Then, the oblique image generation unit 13 stores the generated data in the storage unit 23. For the three points pa, pb, and pc at this time, for example, it is desirable to select the tip point of the protruding portion of the bone. This is because the data analysis of the oblique image generation unit 13 is facilitated.

  The right side of FIG. 15 schematically shows the positional relationship of each part pa, pb, pc, R represented by this positional relationship data. The oblique image generation unit 13 is based on the positional relationship data generated in the previous trabecular analysis and the set of a plurality of tomographic images D (current spatial data) acquired in the later trabecular analysis. The cut surface of Obl is rotated and translated.

  The operation of the oblique image generation unit 13 related to the positional relationship data will be described. When the trabecular analysis is performed, the oblique image generation unit 13 extracts three characteristic points pa, pb, and pc from the contour shape of the bone from the spatial data constituted by the set of tomographic images D by image processing. Then, the position information is sent to the trabecular bone analysis unit 14. When the trabecular analysis 14 performs the trabecular analysis, the trabecular analysis 14 includes the position information of the plane including the analysis range R at this time (the analysis range including plane) and the position information of the three points pa, pb, and pc. Are stored in the storage unit 23 in association with each other. The position information obtained at this time will be referred to as previous position information.

  Then, when trabecular analysis is performed on the same position of the same subject at a later date, the oblique image generation unit 13 calculates the contour shape of the bone from the spatial data configured by the set of tomographic images D obtained this time. Among them, characteristic three points pa, pb, pc are extracted by image processing, and their positional information is acquired. Then, the oblique image generation unit 13 grasps the positional relationship between the previous three points pa, pb, pc and the analysis range inclusion plane based on the previous position information stored in the storage unit 23. Then, the oblique image generation unit 13 acquires a plane position that is the same as the positional relationship between the previous three points and the analysis range inclusion plane based on the positions of the current three points.

  An operation when the oblique image generation unit 13 acquires a plane will be described. The current spatial data includes a map of three points pa, pb, and pc on the previous spatial data. The positions of the three points pa, pb, and pc that are the original images on the previous spatial data are different from the positions of the three points pa, pb, and pc that are the mapping on the current spatial data. This is because the position of the subject is different between the previous imaging and the current imaging. Therefore, the oblique image generation unit 13 generates a matrix for converting the positions of the three points pa, pb, and pc of the original image into the positions of the three points pa, pb, and pc of the mapping. The oblique image generation unit 13 converts the analysis range inclusion plane on the previous spatial data based on this matrix, and acquires a new plane. The positional relationship between this plane and the three points pa, pb, pc is a reproduction of the positional relationship between the analysis range inclusion plane and the three points pa, pb, pc in the previous imaging.

  The operation of the oblique image generation unit 13 after acquiring the plane position will be described. The oblique image generation unit 13 rotates the cut surface from the initial state described above so that the cut surface of the oblique image Ob1 coincides with the acquired plane. Similarly, the oblique image generation unit 13 translates the oblique image Obl on the above-described analysis range inclusion plane, thereby matching the position of the analysis range R included in the oblique image Obl with the analysis range R of the previous analysis. .

  If the rotation angle of the oblique image Obl can be automatically acquired in this manner, an accurate change with time can be diagnosed without the operator setting the inclination and position of the oblique image Obl. Further, as in the present invention, if the analysis range R, which is a region for performing trabecular analysis on the oblique image, is determined by the trabecular analysis unit 14 based on the shape of the contour of the bone reflected in the plurality of tomographic images, Therefore, trabecular analysis can be performed without analyzing the whole image of the above, and the trabecular analysis apparatus 1 having a high analysis speed can be provided.

  (2) Although the embodiment described above is a medical device, the present invention can also be applied to industrial and nuclear devices.

  (3) X-rays referred to in the above-described embodiments are an example of radiation in the present invention. Therefore, the present invention can be applied to radiation other than X-rays.

  (4) In the above-described embodiments, it is assumed that the trabecular analysis has already been performed on the subject, but the present invention is not limited to this configuration. That is, the trabecular bone analysis apparatus of the present invention may perform an operation for generating the oblique image Ob1 even for the subject M for which trabecular analysis has not been performed previously. The oblique image generation unit 13 at this time operates in accordance with an operator's instruction made through the console 26. With such a configuration, a trabecular analysis can be performed using a tomographic image at the cut surface desired by the operator, and an apparatus with improved analysis freedom can be provided.

1 Trabecular analysis device 3 X-ray tube (radiation source)
4 FPD (detection means)
7a X-ray tube moving mechanism (radiation source moving means)
7b FPD moving mechanism (detector moving means)
8a X-ray tube movement control unit (radiation source movement control means)
8b FPD movement control unit (detector movement control means)
11 Image generation unit (image generation means)
12 Tomographic image generating unit (tomographic image generating means)
13 Oblique image generator (Oblique image generator)
14 Trabecular analysis part (trabecular analysis means)
26 Console (input means)

Claims (8)

A radiation source that emits radiation;
Radiation source moving means for moving the radiation source relative to the subject;
Radiation source movement control means for controlling the radiation source movement means;
Detection means for detecting radiation transmitted through the subject;
Detector moving means for moving the detection means relative to the subject;
Detector movement control means for controlling the detector movement means;
Image generating means for generating an image based on the output of the detecting means;
Generate oblique images, which are tomographic images inclined at an arbitrary inclination angle with respect to the top plate on which the subject is placed, based on images continuously taken while moving the radiation source and the detection means relative to the subject. Oblique image generation means
A trabecular analysis device comprising: trabecular analysis means for calculating data for quantifying a trabecular state based on the oblique image. In the trabecular bone analysis device according to claim 1,
Comprising tomographic image generation means for generating a plurality of tomographic images whose cut sections are parallel to each other based on the continuously shot images;
The oblique image generation means generates the oblique image that is not parallel to the tomographic image based on a plurality of the tomographic images. In the trabecular bone analysis device according to claim 1 or 2,
An apparatus for analyzing a trabecular bone comprising input means for inputting an instruction to adjust an inclination angle between the oblique image and the tomographic image generated by the oblique image generating means. In the trabecular bone analysis apparatus according to claim 1 to claim 3,
The oblique image generation means determines the inclination angle between the oblique image and the tomographic image based on the shape of the outline of the bone reflected in a plurality of tomographic images. In the trabecular bone analyzer according to any one of claims 1 to 4,
The trabecular bone analyzing apparatus determines an analysis range which is a region for performing trabecular analysis on an oblique image based on a shape of a bone contour reflected in a plurality of tomographic images. In the trabecular bone analysis apparatus according to any one of claims 1 to 5,
The oblique image generation means generates the oblique image by a trilinear interpolation method. In the trabecular bone analysis apparatus according to any one of claims 1 to 5,
The oblique image generation means generates the oblique image by a tricubic interpolation method. The trabecular bone analyzer according to any one of claims 1 to 7 analyzes a temporal change of a trabecular bone by newly performing a trabecular analysis on a subject for which trabecular analysis has been performed previously. Device to
The cut surface of the oblique image generated by the oblique image generation means is the same plane as the cross section of the bone of the subject in the analyzed tomographic image that has been subjected to trabecular analysis during the previous trabecular analysis. Trabecular analysis device.

Images