Head positioning standard method

Abstract

Limited precision of head standardization is a problem in the prior art.　In the present invention, positioning of a patient head is standardized using two cameras, namely, a first digital camera 11 and a second digital camera 12. In a profile positioning step, while a display on a first monitor 13 is viewed, the vertical position of the first digital camera 11 is adjusted, and instructions are given to the patient to adjust the forward-backward position of the head so that the point of intersection of a first vertical reference line VL1 and a first horizontal reference line HL1 corresponding to the camera optical axis of the first digital camera 11 is in the center of the ear canal of the patient. In a front positioning step, while a display on a second monitor 16 is viewed, the vertical position of the second digital camera 12 is adjusted so that a second horizontal reference line HL2 passes through the center of the left and right eyeballs of the patient, and instructions are given to the patient to adjust the left-right inclination of the head and face such that the heights of the left and right eyes are equal, and to adjust the left-right orientation of the head and face so that a second vertical reference line VL2 passes through the center of the left and right eyes of the patient.

Description

Technical Field

[0001] The present invention relates to a head positioning standard method for performing standard head X-ray imaging.

Background Art

[0002] In the medical field, particularly in orthodontic treatment for harmonizing the positional relationship between the dentition and the craniofacial skeleton, surgical orthodontic treatment for surgically improving craniofacial distortion or morphological abnormalities, cosmetic surgery treatment, or plastic surgery treatment, etc., quantitative morphological diagnosis of the craniofacial region, that is, accurate morphological evaluation before and after treatment, X-ray image information of the craniofacial skeleton is indispensable.

[0003] Also, in quantitative morphological diagnosis for diagnosing not the presence or absence of lesions but the characteristics and changes in form, the clinical basis and reproducibility of the orientation of the craniofacial region to be measured and evaluated, that is, the diagnostic orientations such as the standard front and left and right side views, are very important as they influence the evaluation and diagnostic content.

[0004] Images simply taken with ordinary X-ray imaging devices change in the orientation and size of the captured images each time they are taken and are not constant. Therefore, even if an image of the skeletal form inside the craniofacial region that cannot be seen with the naked eye is obtained, it is difficult to quantitatively evaluate the characteristics of the craniofacial skeleton and temporal changes such as before and after treatment.

[0005] [[ID=〔24〕]]Around 1940, about 40 years after the invention of medical X-ray imaging devices, a head standard imaging method for standardizing the head position at a certain distance and in a certain orientation and imaging, and a head standard X-ray imaging device for that purpose were devised. For the first time, quantitative morphological diagnosis of the craniofacial region became possible, and since then, it has been widely used as a major diagnostic material for craniofacial skull morphology.

[0006] The head X-ray standard photograph (cephalogram) taken with this head standard X-ray imaging device has a problem that due to the standard error of the head position, the position and orientation from the irradiation port change slightly each time it is imaged, affecting the form of the projection image and distorting the size and shape of the form, and it is not constant.

[0007] Conventional standardized head radiography systems insert ear rods (positioning devices) into the patient's ear canals (external auditory canals) on both sides to position the patient's head and then perform standardized head radiography (see Non-Patent Literature 1). Since its creation in 1940, all standardized head radiography systems have used this ear rod method, and no other standardized head radiography system has yet been developed. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] "Standardized Head X-ray Radiography" (http: / / rada.or.jp / database / home4 / normal / ht-docs / member / synopsis / 030084.html) [Overview of the project] [Problems that the invention aims to solve]

[0009] In current cephalometric radiography methods, head sizing is performed using only an ear rod. Therefore, it is difficult to completely control the play caused by differences in size and shape between the ear rod and the external auditory canal, as well as the vertical rotational displacement of the head position around the ear rod. This limits the accuracy of head sizing using only an ear rod, which is a challenge.

[0010] Furthermore, lateral cephalometric radiographs are used not only for the evaluation and diagnosis of morphological features and changes in the maxillofacial skeleton, but also for the evaluation and diagnosis of the positional relationship and relationship between the morphological features of the maxillofacial bones and surrounding movable organs such as the airway, tongue position, and cervical vertebrae. The positional relationship between the patient's posture and head position during imaging, that is, the relationship between the cervical vertebrae and head position, also affects the shape of the airway and the position of the tongue that are displayed. Therefore, there is a need for a new positioning standard that considers not only the head position, but also the head position and the entire body as an integrated whole.

[0011] This invention proposes a standardized method for head positioning that enhances clinical evidence and reproducibility.

[0012] Furthermore, the present invention aims to provide a standard method for positioning the head in a posture that maintains the positional relationship between the head position and the body, that is, a posture with high clinical basis and reproducibility.

[0013] The primary objective is to improve the clinical usefulness of the head standardization imaging data itself obtained using subsequent X-ray imaging equipment (such as a head X-ray standardization imaging device and a head X-ray CT imaging device) by adopting the head positioning standardization method according to the present invention, thereby improving the accuracy of maxillofacial morphology diagnosis and treatment. [Means for solving the problem]

[0014] The present invention has been made to achieve the above objective, and the invention described in claim 1 is a head positioning standard method for head X-ray standard radiography, comprising: a side positioning step in which a first digital camera, whose camera optical axis is located on the same line as the X-ray imaging axis for imaging the side of a patient's head placed in the imaging space, is used to image the side of the patient's head, and a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera are displayed on a first monitor together with the image of the side of the patient's head; and a front positioning step in which a second digital camera, which has a horizontal camera optical axis that forms a 90° angle in plan view with the camera optical axis of the first digital camera and is directed toward the head and face of the patient placed in the imaging space, is used to image the head and face of the patient, and a second horizontal reference line and a second vertical reference line determined by the camera optical axis of the second digital camera are displayed on a second monitor together with the image of the head and face of the patient, wherein in the side positioning step, while viewing the display on the first monitor, the first horizontal reference line and the first horizontal reference line corresponding to the camera optical axis of the first digital camera The head positioning standard method includes adjusting the vertical position of the first digital camera together with the X-ray imaging axis so that the intersection of the first vertical reference line and the first vertical reference line is at the center of the patient's external auditory canal, and instructing the patient to adjust the front-to-back position of the head; in the front positioning step, while viewing the display on the second monitor, adjusting the vertical position of the second digital camera so that the second horizontal reference line passes through the center of the patient's left and right eyeballs, and instructing the patient to adjust the left-to-right tilt of the head and face to make the height of the left and right eyes equal; and instructing the patient to adjust the left-to-right orientation of the head and face so that the second vertical reference line passes through the center of the patient's left and right eyes; and after the adjustments in the side positioning step and the front positioning step are completed and head positioning is finished, the shutters of the first digital camera and the second digital camera are pressed to record the side view of the head in association with the first horizontal reference line and the first vertical reference line, and the head and face in association with the second horizontal reference line and the second vertical reference line, and a recording step is included to record the height positions of the first digital camera and the second digital camera.

[0015] The invention described in claim 2 is a head X-ray standard imaging method characterized in that, after completing the recording step described in claim 1, the first digital camera is moved away from the X-ray imaging axis and X-ray irradiation is performed.

[0016] The invention described in claim 3 is a head positioning standard method for X-ray CT head imaging, comprising: a side positioning step in which a first digital camera having a horizontal camera optical axis directed toward the side of the patient's head, positioned in the imaging space, is used to image the side of the patient's head, and a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera are displayed on a first monitor together with the image of the patient's side of the head; and a front positioning step in which a second horizontal reference line and a second vertical reference line, which are determined by a horizontal camera optical axis that forms a 90° angle in plan view with the camera optical axis of the first digital camera and directed toward the head and face of the patient, positioned in the imaging space, are displayed on a second monitor together with the image of the patient's head and face, wherein in the side positioning step, while viewing the display on the first monitor, the vertical position of the first digital camera is adjusted so that the intersection of the first horizontal reference line and the first vertical reference line corresponding to the camera optical axis of the first digital camera is at the center of the patient's external auditory canal. The head positioning standard method includes adjusting the position and instructing the patient to adjust the front-to-back position of the head; in the front positioning step, while viewing the display on the second monitor, adjusting the vertical position of the second digital camera so that the second horizontal reference line passes through the center of the patient's left and right eyeballs, and instructing the patient to adjust the left-to-right tilt of the head and face to make the height of the left and right eyes equal; and instructing the patient to adjust the left-to-right orientation of the head and face so that the second vertical reference line passes through the center of the patient's left and right eyes; and after the adjustments in the side positioning step and the front positioning step are completed and head positioning is finished, the shutters of the first digital camera and the second digital camera are pressed to record the side view of the head in association with the first horizontal reference line and the first vertical reference line, and the head and face in association with the second horizontal reference line and the second vertical reference line, and a recording step is included to record the height positions of the first digital camera and the second digital camera.

[0017] The invention described in claim 4 is a head positioning standard method according to claim 1 or 3, wherein in head positioning performed again on the same patient, in the lateral positioning step, the height of the first digital camera is set to the height position recorded in the previous positioning, the lateral image of the patient's head captured by the first digital camera, as well as the first horizontal reference line and the first vertical reference line are displayed on the first monitor, and the previously recorded lateral image of the head, the first horizontal reference line and the first vertical reference line are read out and displayed overlaid on the display on the first monitor, and the patient is instructed to position the intersection of the first horizontal reference line and the first vertical reference line corresponding to the camera optical axis of the first digital camera within the patient's external auditory canal. This head positioning standard method includes adjusting the front-to-back position of the head so that it is aligned with the heart and the contours overlap with the previous image, setting the height of the second digital camera to the height recorded in the previous positioning step, displaying the patient's head and face image captured by the second digital camera, as well as the second horizontal reference line and the second vertical reference line, on the second monitor, reading the previously recorded head and face image, the second horizontal reference line, and the second vertical reference line and displaying them overlapping on the display on the second monitor, instructing the patient to make the heights of the left and right eyes equal, adjusting the left-to-right orientation of the head and face, and adjusting so that the contours overlap with the previous image.

[0018] The invention described in claim 5 is a head positioning standard method according to claim 4, which includes a recording step in which, after the adjustments in the side positioning step and the front positioning step are completed and head positioning is completed, the shutters of the first digital camera and the second digital camera are pressed to record a side view of the head associated with a first horizontal reference line and a first vertical reference line, and a face view of the head associated with a second horizontal reference line and a second vertical reference line, and the height positions of the first digital camera and the second digital camera are recorded. [Effects of the Invention]

[0019] According to the present invention, the patient's head position can be precisely positioned and standardized using head position images obtained by two digital cameras having orthogonal lens optical axes in a plan view, along with horizontal and vertical reference lines based on the lens optical axes.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a head positioning standard device according to an embodiment of the present invention incorporated in a head X-ray standard imaging device. [Figure 2] FIG. 2 is a front view showing a schematic configuration of a head X-ray standard imaging device incorporating the head positioning standard device shown in FIG. 1. [Figure 3] FIG. 3 is a plan view showing a schematic configuration of a head X-ray standard imaging device incorporating the head positioning standard device shown in FIG. 1. [Figure 4] FIG. 4 is a schematic diagram of a configuration for retreating the first digital camera 11 from above the X-ray imaging axis. [Figure 5] FIG. 5 is a schematic diagram of a configuration for vertically moving the second digital camera 12 up and down. [Figure 6] FIGS. 6(A), (B), and (C) are illustrative diagrams showing the side positioning steps. [Figure 7] FIGS. 7(A), (B), and (C) are illustrative diagrams showing the front positioning steps. [Figure 8] FIG. 8 is a perspective view showing a schematic configuration of a head positioning standard device according to another embodiment of the present invention incorporated in a head X-ray standard imaging device. [Figure 9] FIG. 9 is a front view showing a schematic configuration of a head X-ray standard imaging device incorporating the head positioning standard device shown in FIG. 8. [[ID=​​​​​​​​​​​​Figure 14 is a perspective view showing an overview of the configuration of a head positioning standard device according to another embodiment of the present invention, when it is incorporated into a cone-beam X-ray CT head imaging device. [Figure 15] Figure 15 is a plan view showing the configuration overview of a cone-beam X-ray CT head imaging system incorporating the head positioning standard device shown in Figure 14. [Figure 16] Figure 16 is a perspective view showing an example of the configuration of a magic mirror 15 used in a head positioning device according to an embodiment of the present invention. [Figure 17] This is a diagram illustrating the operation of the Magic Mirror 15. [Modes for carrying out the invention]

[0021] The embodiments of the present invention will be described in detail below with reference to the drawings. [First Embodiment] Figure 1 is a perspective view showing the configuration overview of a head positioning standard device according to one embodiment of the present invention, when incorporated into a head X-ray standard imaging apparatus. Figure 2 is a front view showing the configuration overview of a head X-ray standard imaging apparatus incorporating the head positioning standard device shown in Figure 1, and Figure 3 is a plan view showing the configuration overview of a head X-ray standard imaging apparatus incorporating the head positioning standard device shown in Figure 1. Hereafter, in the explanation of directions in Figures 1 to 3, the left-right direction will be referred to as the X direction, the front-back direction as the Y direction, and the up-down direction as the Z direction.

[0022] Referring to Figures 1-3, the head X-ray standard radiography apparatus 1 comprises an X-ray irradiation unit 2 and an X-ray detection unit 3. The distance between the X-ray irradiation unit 2 and the X-ray detection unit 3 is set to 165 cm in the X direction, and the design ensures that the center of the patient's head (the patient's midline) is positioned 15 cm in front of the X-ray detection unit 3 when viewed from the X-ray irradiation unit 2 in the X direction. This is a globally standardized head X-ray radiography specification.

[0023] Conventionally, ear rods have been used to position the patient's head. The ear rod is a fixing device used to position the center of the patient's head 15 cm in front of the X-ray detection unit 3 when viewed in the X direction.

[0024] In conventional methods, the patient's three-dimensional head position is fixed and positioned using three-dimensional means, relying on the ear rods and the operator's visual observation. Specifically, the left and right ear rods are inserted into the left and right external auditory canals of the patient's head, clamped together, and fixed in the center of the ear rods. The vertical orientation of the head is then positioned around these clamped ear rods. Therefore, the orientation of the face is largely determined by the contact position and condition within the left and right external auditory canals at the time of clamping with the ear rods, and the remaining vertical orientation (centered on the ear rods) is determined by the operator's visual observation. The operator's visual observation at this time is based on the operator's viewpoint, and the direction changes with each image, making it inconsistent. Furthermore, the positional relationship of the ear rods inserted into the external auditory canal with respect to the external auditory canal cannot be visually observed. Consequently, even if the X-ray imaging axis is standardized with the center of the ear rods, it is difficult to accurately position the ear rods in the center of the external auditory canal. Also, visually positioning the face orientation to match the imaging direction is insufficient in terms of accuracy. Therefore, the errors in head positioning, standardization, and reproduction that occur with each image capture pose a fundamental challenge in improving the accuracy and reliability of maxillofacial morphology diagnosis.

[0025] Furthermore, positioning with ear rods is based on the idea of ​​fixing the three-dimensional shape of the unstandardized human body structure with a single standardized three-dimensional shape. Naturally, there will be some three-dimensional play between them. Even if the left and right ear rods are used to firmly clamp the ear, tightening from both sides, rather than just one, only causes strong pinching at two points of contact on the left and right, rendering the person immobile due to pain. This does not correct the difference in three-dimensional shape or play between the left and right ear rods and the external auditory canal. Rather, it only distorts the head position and posture. It is rare for the structure of a human face to be perfectly symmetrical in position and shape. Moreover, the inside of the external auditory canal is covered with soft tissue, is elastic, and has a pain-sensing function, so there are limits to the accuracy of positioning with ear rods.

[0026] Thus, in fixation methods using ear rods that attempt to fix the physical head in three dimensions, unresolved three-dimensional play occurs between the contact fixation points. There are limitations to correcting the three-dimensional orientation of the head position by visual inspection, which is not fixed by the operator and can only be checked from one direction at a time.

[0027] In this embodiment, instead of an ear rod, two digital cameras, a first digital camera 11 and a second digital camera 12, are used to position the patient's head.

[0028] The first digital camera 11 is positioned so that its optical axis lies on the same line as the X-ray imaging axis emitted from the X-ray irradiation unit 2. Specifically, the first digital camera 11 is mounted on the housing of the X-ray irradiation unit 2, and its lens optical axis is positioned so that it lies on the same line as the X-ray imaging axis emitted from the X-ray irradiation unit 2. The X-ray imaging axis is an axis that extends horizontally in the X direction from the X-ray irradiation unit 2, through the center of the patient's external auditory canal, to the X-ray detection unit 3. The first digital camera 11 is positioned so that the optical axis of its lens is on the same axis as this X-ray imaging axis. Furthermore, since the first digital camera 11 is mounted on the housing of the X-ray irradiation unit 2, when the X-ray irradiation unit 2 moves vertically up and down in the Z direction along the support column 5, the first digital camera 11 also moves vertically up and down in the Z direction. In other words, the X-ray imaging axis emitted from the X-ray irradiation unit 2 and the optical axis of the first digital camera 11 are always located on the same axis, regardless of the height positions of the X-ray irradiation unit 2 and the first digital camera 11.

[0029] However, when the X-ray irradiation unit 2 irradiates X-rays to perform X-ray standard radiography, the first digital camera 11 is retracted to a position that does not obstruct the X-ray irradiation. For example, as shown in Figures 4(A) and 4(B), the first digital camera 11 is mounted so as to be able to slide horizontally in the Y direction relative to the housing of the X-ray irradiation unit 2. Therefore, as shown in Figure 4(B), when the first digital camera 11 is retracted, the X-ray irradiation unit 2 can irradiate X-rays without any problems.

[0030] Alternatively, instead of arranging the camera optical axes of the first digital cameras in a straight line along the X-ray imaging axis, multiple first digital cameras may be arranged in the X-ray irradiation unit 2, centered on the X-ray irradiation port (starting point of the X-ray imaging axis). For example, by arranging two digital cameras on the y-axis passing through the center of the X-ray irradiation port (X-ray imaging axis), one in front of the center, and two digital cameras on the Z-axis passing through the center, one above and one below the center, so that the optical axes of each camera are parallel to the X-ray imaging axis, a lateral image centered on the external auditory canal, similar to the camera image from the X-ray imaging direction, can be obtained by correcting and displaying each image based on the intersection of a horizontal reference plane and a vertical reference plane passing through the X-ray imaging axis, i.e., the external auditory canal on the X-ray imaging axis. Although not strictly the same as the camera image arranged on the X-ray imaging axis, the effect on positioning accuracy based on each reference plane passing through the imaging axis is the same because the horizontal and vertical reference planes are precisely standardized to match the imaging axis. Furthermore, by properly and consistently standardizing the positional relationship (arrangement) of each camera with respect to the center of the X-ray imaging port, it is possible to obtain images of the external auditory canal and lateral camera images that are always the same, thus achieving sufficient standardization and reproducibility. This method allows for equivalent accuracy to be obtained without having to move the aforementioned first digital camera to a position that does not interfere with X-ray imaging, leading to a reduction in the manufacturing cost of the imaging device and a reduction in the time required to maintain the head position during imaging.

[0031] A first monitor 13 is connected to the first digital camera 11 for displaying the image captured by the first digital camera 11. The first monitor 13 may be located in the operator's room, which is separated from the room where the head X-ray standard imaging device 1 is located. The first monitor 13 can display the first horizontal reference line HL1 and the first vertical reference line VL1, which are determined by the optical axis of the first digital camera 11. That is, since the viewpoint direction of the first digital camera 11 is the optical axis direction in the X direction, a horizontal reference line extends horizontally in the Y direction from the optical axis, and a vertical reference line extends vertically in the Z direction from the optical axis, so the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1 is the optical axis.

[0032] The first monitor 13 displays a lateral image of the patient's head as seen in the direction of the optical axis in the X direction, captured by the first digital camera 11, along with the first horizontal reference line HL1 and the first vertical reference line VL1.

[0033] The second digital camera 12 is positioned at a 90° angle to the optical axis of the first digital camera 11 in a plan view. For example, the second digital camera 12 is mounted on a support column 14 erected vertically on the base 6, and its height is adjustable by moving it up and down in the Z direction along the support column 14, as shown in Figure 5. The support column 14 is positioned 15 cm away from the X-ray detection unit 3 when viewed in the X direction. Therefore, the optical axis of the second digital camera 12 is an optical axis that extends horizontally in the Y direction at a position 15 cm away from the X-ray detection unit 3 in the X direction. Furthermore, since the optical axis of the second digital camera 12 extends in the Y direction and the optical axis of the first digital camera 11 extends in the X direction, the two optical axes have a 90° angle in a plan view.

[0034] The second digital camera 12 is a camera for capturing images of the patient's head and face, and its vertical position can be adjusted to match the patient's height. As will be described later, the optical axis of the second digital camera 12 is adjusted so that it is at the height of the patient's eyes.

[0035] Furthermore, a one-way mirror 15 may be provided in front of the lens of the second digital camera 12, so that the patient cannot directly see the lens of the second digital camera 12, and can instead see their own face reflected in the one-way mirror 15.

[0036] In other words, the setup allows the patient to see their own face reflected in the magic mirror 15, and by marking a horizontal reference line and a midline on the magic mirror 15 in line with the camera position, the patient can easily adjust their head position themselves or according to the instructions of the photographer, using these reference lines as a guide.

[0037] The magic mirror 15 may be fixedly held on the support column 14, or it may be configured to move up and down together with the up and down movement of the second digital camera 12 when the second digital camera 12 moves up and down along the support column 14.

[0038] A second monitor 16 is connected to the second digital camera 12 for displaying the image captured by the second digital camera 12. The second monitor 16 may also be located in the operator's room, which is separated from the room where the head X-ray standard imaging device 1 is located. The second monitor 16 can display the second horizontal reference line HL2 and the second vertical reference line VL2, which are determined by the optical axis of the second digital camera 12. That is, since the viewpoint direction of the second digital camera 12 is the optical axis direction in the Y direction, a horizontal reference line extends horizontally in the X direction from the optical axis, and a vertical reference line extends vertically in the Z direction from the optical axis, so the intersection of the second horizontal reference line HL2 and the second vertical reference line VL2 indicates the optical axis.

[0039] The second monitor 16 displays the patient's head and face as seen in the direction of the optical axis in the Y direction captured by the second digital camera 12, along with the second horizontal reference line HL2 and the second vertical reference line VL2.

[0040] If the first monitor 13 and the second monitor 16 are, for example, installed side by side in the operator's room, the operator can simultaneously view the first monitor 13 and the second monitor 16 and correctly position the patient's head prior to standard head radiography based on the lateral image of the patient's head as seen from the viewpoint of the first digital camera 11 and the head and face image as seen from the viewpoint of the second digital camera 12, which is at a 90° angle to the first digital camera 11.

[0041] The following section provides specific examples of how to position the head.

[0042] (1) First, the operator instructs the patient to place their feet on the position of the head X-ray standard radiography device 1 and stand in a natural posture with their back straight.

[0043] The head X-ray radiography apparatus 1 has a horizontally positioned base 6, and the base 6 has a foot position indicator 7 on it, which indicates where the patient should stand based on the imaging direction and position. The patient stands naturally on the base 6 according to this foot position indicator 7.

[0044] (2) Perform the side positioning step.

[0045] In the lateral positioning step, the operator adjusts the height of the first digital camera 11 while viewing the display on the first monitor 13, so that the intersection of the first horizontal reference line HL1, which corresponds to the optical axis of the first digital camera 11, and the first vertical reference line VL1 is at the same height as the center of the patient's external auditory canal.

[0046] For example, if the image displayed on the first monitor 13 is the image shown in Figure 6(A), the X-ray irradiation unit 2 and X-ray detection unit 3, held by the arm 8, are displaced upward along the support column 5. Since the support column 5 is erected vertically on a horizontal base 6, the X-ray irradiation unit 2 and X-ray detection unit 3 are displaced vertically upward. As mentioned above, the first digital camera 11 is attached to the housing of the X-ray irradiation unit 2, so as the X-ray irradiation unit 2 is displaced upward, the first digital camera 11 is also displaced upward, and its horizontal optical axis remains horizontal as it is displaced upward.

[0047] This fixes the height position of the first digital camera 11 and stores it when the image displayed on the first monitor 13 is the image shown in Figure 6(B). The height position of the first digital camera 11 at this time can be represented by the height position of the arm 8 on the support column 5, so that height position may also be stored.

[0048] Even when the image displayed on the first monitor 13 becomes the image shown in Figure 6(B), the optical axis of the first digital camera 11 (the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1) is not centered on the patient's external auditory canal. This means that the patient's head is positioned slightly backward.

[0049] The surgeon then instructs the patient to move their head slightly forward. While watching the image on the first monitor 13 displayed by the first digital camera 11, the surgeon instructs the patient to maintain the current position when the patient's head is in the position shown in Figure 6(C).

[0050] (3) Perform the front positioning step.

[0051] In the frontal positioning step, the operator, while viewing the image displayed on the second monitor 16, gives instructions to the patient so that the patient's head and face are facing straight ahead. For example, if the patient's gaze is downward, the operator instructs the patient to lift their face, and if the patient's face is tilted upward, the operator instructs the patient to tuck their chin and look straight ahead. This instruction corrects the vertical tilt of the patient's head and face, so that they are facing straight ahead.

[0052] Then, if the image displayed on the second monitor 16 is the image shown in Figure 7(A), the height position of the second digital camera 12 is slightly low, so the height position of the second digital camera 12 is displaced vertically upward along the support column 14. Then, when the image displayed on the second monitor 16 becomes the image shown in Figure 7(B), the height position of the second digital camera 12 is fixed and stored. Since the support column 14 supporting the second digital camera 12 is erected vertically on the horizontal base 6, the height position of the second digital camera 12 can be represented by its height position on the support column 14, so that height position may also be stored.

[0053] If the image displayed on the second monitor 16 is the image shown in Figure 7(B), the patient's head and face are slightly tilted to the right. Therefore, the surgeon instructs the patient to slightly raise their head and face to the left.

[0054] Furthermore, in the display of the second monitor 16, the second vertical reference line VL2 corresponds to the midline of the patient's head and face. Therefore, the patient is instructed to adjust the left-right orientation of their head and face so that their head and face are symmetrical with respect to the second vertical reference line VL2, specifically so that the second vertical reference line VL2 is positioned between the left and right eyeballs, or so that the second vertical reference line VL2 passes through the center of the nose.

[0055] At this time, a marker was used to mark the horizontal reference line and the midline reference line passing through the optical axis of the second digital camera. Mirror 15 By positioning the second camera in front of the second camera, it becomes easier to confirm and reflect the direction and amount of movement indicated by the surgeon based on the positional relationship between the patient's face reflected in the magic mirror 15 and the reference line. It also becomes easier to show the surgeon what the patient considers to be the front. This allows both the patient and the surgeon to confirm and reach a common, agreeable frontal orientation. This is effective in confirming the treatment goals that both the patient and the surgeon are imagining, and as a result, it leads to aiming for and achieving a treatment result that is acceptable to the patient, including symmetry based on the frontal orientation in the shared understanding, and thus increases patient satisfaction with the treatment.

[0056] Then, with the image displayed on the second monitor 16 as shown in Figure 7(C), the patient is instructed to maintain their current position and state.

[0057] (4) Perform the recording step.

[0058] The recording step is performed after the patient's head position has been determined in the aforementioned lateral positioning step and frontal positioning step. Before performing the recording step, the displayed images on the first monitor 13 and the second monitor 16 are checked. If the displayed images are misaligned due to patient movement or other reasons, the lateral positioning step or frontal positioning step may be repeated to determine the patient's head position again.

[0059] In the recording step, the shutters of the first digital camera 11 and the second digital camera 12 are released to save and record the captured images of the side view of the head and the head and face. The shutters of the first digital camera 11 and the second digital camera 12 may be operated simultaneously by remote control.

[0060] The lateral head image captured by the first digital camera 11 may be recorded in association with the first horizontal reference line HL1 and the first vertical reference line VL1. Similarly, the head and face image captured by the second digital camera 12 may be recorded in association with the second horizontal reference line and the second vertical reference line.

[0061] In addition, the recording step also records the height position of the first digital camera 11 and the height position of the second digital camera 12.

[0062] Although the schematic diagrams of the head X-ray imaging apparatus incorporating the head positioning standard device shown in Figures 1-3 do not show the personal computer and memory used to perform the recording step described above, the recording step is performed by a personal computer and memory connected to the first digital camera 11, the second digital camera 12, the first monitor 13, and the second monitor 16.

[0063] Through the above process, after the patient's head is positioned in the imaging space of the head X-ray standard radiography apparatus 1, X-rays are emitted from the X-ray irradiation unit 2, and the X-rays that have passed through the positioned head are detected by the X-ray detection unit 3, thereby obtaining a so-called head X-ray standard radiograph. When X-rays are emitted from the X-ray irradiation unit 2, as mentioned above, the first digital camera 11 is automatically moved to a position that does not obstruct the X-ray irradiation.

[0064] Furthermore, the obtained head X-ray images may be stored in association with the head lateral images and head-face images recorded in the recording step described above.

[0065] Next, we will explain the positioning method for determining the head position of a patient when performing a head X-ray standardization scan on the same patient after a certain period of time has elapsed.

[0066] (1) The patient stands naturally on the base 6 in accordance with the foot position indicator 7 in the head X-ray standard radiography apparatus 1. At this time, if there is video footage from a fixed-point digital camera for the feet that captured the patient's foot position during the previous head positioning, that video may be used to position the patient on the base 6 in the same position as before (the same position along the foot position indicator 7).

[0067] (2) Perform the side positioning step.

[0068] In the lateral positioning step, the height position of the first digital camera 11 recorded in the previous positioning is read out, and the height of the first digital camera 11 is set to the read out height. Specifically, the X-ray irradiation unit 2 and the X-ray detection unit 3, which are held by the arm 8, are displaced along the support column, and the height positions of the X-ray irradiation unit 2, the X-ray detection unit 3, and the first digital camera 11 are set to the height positions used in the previous lateral positioning.

[0069] As a result, the first monitor 13 displays an image similar to the image shown in Figure 6(B) or Figure 6(C), in which the first horizontal reference line HL1 passes through the center of the patient's external auditory canal. In other words, it indicates that the height of the first digital camera 11 has reached the desired height, but the anterior-posterior position of the patient's head does not match the desired position.

[0070] The surgeon then instructs the patient to move their head forward or backward, and when the patient's head is in the position shown in Figure 6(C), that is, when the optical axis of the first digital camera 11 (the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1) is at the center of the patient's external auditory canal, the surgeon instructs the patient to maintain the current position and state.

[0071] Furthermore, in the lateral positioning step, the lateral head image, the first horizontal reference line HL1, and the first vertical reference line VL1 recorded in the previous positioning step may be read out and displayed on the display of the first monitor 13. The display of the read out first horizontal reference line HL1 and first vertical reference line VL1 on the first monitor 13 will perfectly overlap with the first horizontal reference line HL1 and first vertical reference line VL1 currently displayed. On the other hand, the read out lateral head image will not normally perfectly overlap with the current image due to changes in the patient's hairstyle, facial expressions, etc. over time, but the center position of the external auditory canal will overlap. Therefore, feature points in the previous image may be searched for, and the position of the head may be adjusted so that they overlap with the current image, and the contours roughly overlap.

[0072] (3) Perform the front positioning step.

[0073] In the front positioning step, the height position of the second digital camera 12 recorded in the previous positioning is read out, and the height of the second digital camera 12 is set to the read out height.

[0074] Then, the operator, while looking at the display screen of the second monitor 16, gives instructions to the patient so that the image of the patient's head and face is facing straight ahead. For example, if the patient's gaze is downward, the operator will instruct the patient to lift their face, and if the patient's face is tilted upward, the operator will instruct the patient to tuck their chin and look straight ahead. As a result of these instructions, the image of the patient's head and face displayed on the second monitor 16 will be corrected from any vertical tilt and will appear to be facing straight ahead.

[0075] As a result, the second monitor 16 displays an image similar to Figure 7(B). That is, an image of the patient's head and face while they are facing straight ahead.

[0076] If the image displayed on the second monitor 16 is similar to the image shown in Figure 7(B), it indicates that the left-right tilt of the patient's head and face has not been adjusted, and the left-right orientation of the patient's head and face has not been adjusted.

[0077] Therefore, the surgeon instructs the patient to adjust the left-right tilt of the head and face so that the second horizontal reference line HL2 passes through the centers of the left and right eyeballs. The surgeon also adjusts the left-right orientation of the head and face so that the second vertical reference line VL2 passes vertically through the centers of the left and right eyes. When the second vertical reference line VL2 passes vertically through the centers of the left and right eyes, the left-right orientation of the head and face may be adjusted so that the second vertical reference line VL2 passes vertically through the center of the nose and vertically through the center of the mouth.

[0078] Furthermore, in the front positioning step, the head and face image, second horizontal reference line HL2, and second vertical reference line VL2 recorded in the previous positioning step may be read out and displayed on the second monitor 16 with an overlap. The display of the read out second horizontal reference line HL2 and second vertical reference line VL2 on the second monitor 16 will perfectly overlap with the second horizontal reference line HL2 and second vertical reference line VL2 currently displayed.

[0079] On the other hand, the retrieved head and face images usually do not perfectly overlap with the current images due to changes in the patient's hairstyle, facial expressions, and other age-related changes. However, they do overlap at the point where the second horizontal reference line HL2 passes through the centers of the left and right eyeballs. Therefore, it is possible to search for facial feature points in the previous image and adjust the position of the head and face so that they overlap with the current image, and so that the facial contours generally overlap.

[0080] Then, with the image displayed on the second monitor 16 as shown in Figure 7(C), the patient is instructed to maintain their current position and state.

[0081] (4) Perform the recording step.

[0082] The content of the recording step is the same as that explained earlier, so we will omit any redundant explanations here.

[0083] Through the above process, the patient's head is standardized and positioned in the imaging space of the head X-ray standard radiography apparatus 1 to the exact same position as during the previous head X-ray standard radiography. After positioning, X-rays are emitted from the X-ray irradiation unit 2, and the X-rays that pass through the positioned head are detected by the X-ray detection unit 3, thereby obtaining a so-called head X-ray standard radiograph.

[0084] The cephalic standardized radiographs obtained in the previous cephalic standardized radiography and those obtained in the current cephalic standardized radiography are both radiographs of a head positioned using the cephalic positioning standardization method according to an embodiment of the present invention. Therefore, the two cephalic standardized radiographs have high standardization accuracy in the frontal and lateral head positions, and are clinically consistent standardized radiographs. By comparing and contrasting the contents of both radiographs, it is useful to perform accurate maxillofacial morphology diagnosis and treatment of patients.

[0085] [Second Embodiment] Figure 8 is a perspective view showing the configuration overview of a head positioning standard device according to another embodiment of the present invention incorporated into a head X-ray imaging apparatus. Figure 9 is a front view showing the configuration overview of a head X-ray imaging apparatus incorporating the head positioning standard device shown in Figure 8, and Figure 10 is a plan view showing the configuration overview of a head X-ray imaging apparatus incorporating the head positioning standard device shown in Figure 8. Hereafter, in the explanation of directions in Figures 8 to 10, the left-right direction will be referred to as the X direction, the front-back direction as the Y direction, and the up-down direction as the Z direction.

[0086] Referring to Figures 8 to 10, the head X-ray standard radiography apparatus 1 comprises a base 6 with a horizontally positioned top surface, a vertically extending support column 5 mounted on the rear edge of the base 6, and a pair of arms 8 (81, 82) attached to the support column 5, extending horizontally on both sides in the X direction with their tips extending in the Y direction. An X-ray irradiation unit 2 is fixed to the tip of arm 81, and an X-ray detection unit 3 is provided at the tip of arm 82. The distance between the X-ray irradiation unit 2 and the X-ray detection unit 3 is set to 165 cm in the X direction, and the apparatus is designed so that the center of the subject's head (the patient's midline) is positioned 15 cm in front of the X-ray detection unit 3 when viewed from the X-ray irradiation unit 2 in the X direction. This is a globally standardized head X-ray radiography specification.

[0087] In this embodiment, two digital cameras, a first digital camera 11 and a second digital camera 12, are used to position the center of the subject's head (i.e., the midline) 15 cm in front of the X-ray detection unit 3, thereby standardizing the position of the head. Since this configuration is the same as that of the first embodiment described earlier, the same reference numbers and reference numerals are used for the same components, and redundant explanations are omitted.

[0088] A further feature of this embodiment is the provision of a third digital camera 21 and a fourth digital camera 22, which, in addition to the head positioning standard, also allows for confirmation and positioning of the patient's posture (body axis) during shooting, similar to the head position, by utilizing the viewpoints of the digital cameras from two orthogonal directions. Furthermore, a fifth digital camera 23 is provided for capturing the foot position.

[0089] Specifically, the third digital camera 21 is held by a support column 24 that is erected on the left edge of the base 6 and extends vertically upward. In a plan view, the support column 24 is positioned in the same Y-direction as the X-ray irradiation unit 2 and the first digital camera 11. As a result, the lens optical axis of the third digital camera 21 is set to be parallel to the lens optical axis of the first digital camera, and the vertical reference line is in the same position in the Y-direction. In other words, the lens optical axis of the third digital camera 21 is designed to be positioned perpendicular to the lens optical axis of the first digital camera.

[0090] Furthermore, an auxiliary arm 25 is provided that extends vertically downward from the arm 82, and the fourth digital camera 22 is held by the auxiliary arm 25. The auxiliary arm 25 is positioned at the same location as the support column 14 when viewed in the X direction in a plan view or front view. That is, it is positioned 15 cm away from the X-ray detection unit 3 in the X direction. As a result, the lens optical axis of the fourth digital camera 22 is set to be parallel to the lens optical axis of the second digital camera and to be on the same line when viewed in a plan view.

[0091] Furthermore, an auxiliary support column 26 is erected vertically at the rear edge of the base 6, 15 cm to the left of the X-ray detection unit 3 in a plan view in the X direction. The fifth digital camera 23 is held on the auxiliary support column 26. The optical axis of the lens of the fifth digital camera 23 is directed in the Y direction and toward the foot position indicator 7.

[0092] The third digital camera 21, the fourth digital camera 22, and the fifth digital camera 23 are connected to a third monitor 27, a fourth monitor 28, and a fifth monitor 29, respectively, for displaying the images captured by each digital camera 21, 22, and 23.

[0093] The head positioning method in the head X-ray imaging apparatus 1 incorporating the head positioning standard device shown in Figures 8-10 is similar to the head positioning method in the head X-ray imaging apparatus 1 described with reference to Figures 1-3, mainly consisting of a lateral positioning step for the side of the head as viewed from the viewpoint direction of the first digital camera 11 and a frontal positioning step for the head and face as viewed from the viewpoint direction of the second digital camera 12, and further includes a body axis lateral positioning step for the posture as viewed from the viewpoint direction of the third digital camera 21 and a body axis posterior positioning step for the posture as viewed from the viewpoint direction of the fourth digital camera 22.

[0094] The procedure may also include a foot positioning step performed in the viewpoint direction of the fifth digital camera 23.

[0095] The purpose of posture is not precise positioning, but rather to capture the center of posture, that is, the body axis. If the body axis is significantly curved, it may affect the positioning of the head, which is supported via the cervical spine. Therefore, maintaining a consistent morphological relationship between head position and posture is essential in head positioning standards.

[0096] Therefore, in this embodiment, when positioning the head, the lateral body axis positioning step and the posterior body axis positioning step are performed prior to the lateral positioning step for the sides of the head and the frontal positioning step for the head and face, so that the head is positioned in a standardized correct posture before the head is positioned.

[0097] Furthermore, when a patient stands naturally on the base 6 of the head X-ray standard radiography apparatus 1 for head X-ray standard radiography, if the patient's foot position is different from the center of the imaging area and the imaging direction each time imaging is performed, it will affect the positioning and reproduction of the head.

[0098] Therefore, when taking images, the first step is to determine the position of the patient's feet by viewing them from the viewpoint direction of the fifth digital camera 23, and setting them to a fixed position that matches the head imaging position and orientation.

[0099] The following section describes a specific example of the head positioning method in the head X-ray radiography apparatus 1, which incorporates the head positioning standard device shown in Figures 8-10.

[0100] (1) Perform the foot positioning step.

[0101] In the foot positioning step, the operator instructs the patient to place their feet on the imaging device of the head X-ray standard radiography apparatus 1 and stand in a natural posture with their back straight.

[0102] The head X-ray radiography apparatus 1 has a horizontally positioned base 6, and the base 6 has a foot position indicator 7 on it where the patient should stand. The patient stands naturally on the base 6 according to this foot position indicator 7.

[0103] In this case, if the patient's foot position is incorrect, for example, if both feet are too close together or too far apart, the surgeon will instruct the patient to correct their foot position. The patient's foot position in this case is confirmed by the image captured by the fifth digital camera 23 in the viewing direction and displayed on the fifth monitor 29.

[0104] Then, once the patient's foot position is determined, the shutter of the fifth digital camera 23 is released, and the image displayed on the fifth monitor 29 is recorded in memory. Figure 11 shows an example of the recorded image related to the foot position.

[0105] (2) Perform the body axis lateral positioning step.

[0106] In the body axis lateral positioning step, the operator adjusts the height of the third digital camera 21 while viewing the display on the third monitor 27, so that the third horizontal reference line HL3, which extends horizontally from the optical axis of the third digital camera 21, is at the height of the patient's shoulders, for example. The operator also instructs the patient to adjust their body position in the anterior-posterior direction so that the third vertical reference line VL3 (this third vertical reference line VL3, which extends vertically from the optical axis of the third digital camera 21, lies on the same straight line as the first vertical reference line VL1 of the first digital camera 11) passes through a position that divides the patient's body approximately equally in the anterior-posterior direction. An example of the image displayed on the third monitor 27 after adjustment is shown in Figure 12. From Figure 12, it can be seen that the patient is standing in a natural posture, and the center of that posture, i.e., the body axis, is aligned with the third vertical reference line VL3.

[0107] (3) Perform the body axis posterior positioning step.

[0108] In the posterior body axis positioning step, the operator adjusts the height of the fourth digital camera 22 while viewing the display on the fourth monitor 28, so that the fourth horizontal reference line HL4, which extends horizontally from the optical axis of the fourth digital camera 22 to the left and right, is at the height of the patient's shoulder, for example.

[0109] Alternatively, the height of the fourth digital camera could be adjusted so that it is at a height midway between the patient's shoulders and waist. Or, one could select a camera at the desired position from multiple fourth digital cameras positioned on the same vertical reference line and display its image on a monitor.

[0110] Furthermore, the patient is instructed to adjust their body position laterally so that the fourth vertical reference line VL4 (which extends vertically up and down from the optical axis of the fourth digital camera 22 and lies on the same straight line as the second vertical reference line VL2 of the second digital camera 12) passes through a position that divides the patient's body almost equally into left and right halves. If, at that time, the height of the patient's shoulders differs on the left and right sides, and there is a difference in shoulder height between the left and right sides with respect to the fourth horizontal reference line HL4, the patient is instructed to adjust the tilt of their posture laterally so that the height of both shoulders becomes equal.

[0111] Figure 13 shows an example of the image displayed on the fourth monitor 28 after adjustment. Figure 13 shows that the patient's posture is not tilted to the left or right, and that the center of that posture, i.e., the body axis, is aligned with the fourth vertical reference line VL4.

[0112] (4) Perform the side positioning step.

[0113] (5) Perform the front positioning step.

[0114] The contents of the side positioning step and the front positioning step are exactly the same as those explained earlier, so we will omit the redundant explanation here.

[0115] (6) Perform the recording step.

[0116] The recording step is performed after positioning the patient's body axis in the aforementioned lateral and posterior body axis positioning steps, and after accurately determining the position of the patient's head in the lateral and frontal positioning steps.

[0117] Before performing the recording step, check the display images on the first monitor 13, the second monitor 16, the third monitor 27, and the fourth monitor 28 to confirm that the patient's position has not shifted due to movement or other reasons.

[0118] In the recording step, the shutters of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22 are pressed to capture and record the side view of the head, the head and face, the side view of the body axis, and the rear view of the body axis. The shutters of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22 may be operated simultaneously by remote control.

[0119] The lateral head image captured by the first digital camera 11 may be recorded in association with the first horizontal reference line HL1 and the first vertical reference line VL1; the head and face image captured by the second digital camera 12 may be recorded in association with the second horizontal reference line HL2 and the second vertical reference line VL2; the lateral body axis image captured by the third digital camera 21 may be recorded in association with the third horizontal reference line HL3 and the third vertical reference line VL3; and the posterior body axis image captured by the fourth digital camera 22 may be recorded in association with the fourth horizontal reference line HL4 and the fourth vertical reference line VL4.

[0120] In addition, the recording step also records the height positions of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22.

[0121] Through the above process, the patient's foot position, body axis position, and head position are determined in the head X-ray radiography apparatus 1. Then, X-rays are emitted from the X-ray irradiation unit 2, and the X-rays that pass through the positioned head are detected by the X-ray detection unit 3, thereby obtaining a so-called head X-ray standard photograph. When X-rays are emitted from the X-ray irradiation unit 2, the first digital camera 11 is automatically moved to a position that does not obstruct the X-ray irradiation.

[0122] [Third Embodiment] Figure 14 is a perspective view showing an overview of the configuration of a head positioning standard device according to another embodiment of the present invention, when incorporated into a cone-beam X-ray CT head imaging system. Figure 15 is a plan view showing an overview of the configuration of a cone-beam X-ray CT head imaging system incorporating the head positioning standard device shown in Figure 14.

[0123] Referring to Figures 14 and 15, the CT head imaging apparatus 30 comprises a vertically erected support column 31 and a support frame 32 that can move linearly in the vertical direction (Z direction in the CT coordinate system) on the support column 31 and extends horizontally from its upper end. Below the tip of the support frame 32 is a rotating arm 34 that can rotate in the horizontal plane around a pivot shaft 33 provided on the support frame 32. An X-ray irradiation unit 35 is provided at one end of the rotating arm 34, and an X-ray detection unit 36 ​​is provided at the other end of the rotating arm 34. In a plan view, the X-ray irradiation unit 35 and the X-ray detection unit 36 ​​face each other with the pivot shaft 33 as the origin. The CT head imaging device 30 rotates a rotating arm 34 horizontally on the patient's head, which is positioned in the imaging space formed in the space below the pivot axis 33, and irradiates it with X-rays from the X-ray irradiation unit 35 in a range of 180° to 360° in a plan view. Based on the X-rays detected by the X-ray detection unit 36, it generates a tomographic X-ray image of the patient's head.

[0124] The CT head imaging device 30 incorporates a head positioning standard device for accurately and reproducibly positioning the patient's head, which is placed in the imaging space, to a predetermined position prior to X-ray CT imaging.

[0125] The first digital camera 11 can be adjusted vertically to match the patient's head position by moving it vertically along the height direction of the support column 31 of the support frame 32. Furthermore, the position of the first digital camera 11 can be shifted vertically and anteriorly (y-axis, z-axis) from its initial position, while maintaining the camera optical axis parallel, to match the position of the external auditory canal at a head position where the patient's facial and head region (lateral view) to be photographed is properly positioned within the CT imaging field of view (FOV). The adjustment position during this process is recorded relative to the initial position. (In CT, the imaging field is fixed, and for people with long faces, high or low external ear positions, etc., the camera position for capturing the external ear must be adjusted to match the head position in order to capture the entire face within the FOV. In the case of CT, moving the camera position does not change the image magnification or display orientation, and if the moved position is recorded, the same position coordinates can be used for subsequent positioning, achieving high reproducibility; therefore, it is not necessarily required to be in the exact same position.)

[0126] Alternatively, the first digital camera could be deployed in multiple units, allowing the system to select the desired camera from the images of multiple cameras. This would reduce the effort required for movement and adjustment, or minimize the need for such adjustments.

[0127] Furthermore, in a plan view, when the position of the first digital camera 11 is at a horizontal 0° (x-axis of the CT imaging coordinate system), the system includes a second digital camera 12 that forms a 90° angle with the camera optical axis of the first digital camera 11 and has a horizontal camera optical axis (y-axis of the CT imaging coordinate system) directed toward the head and face of the patient placed in the imaging space.

[0128] The second digital camera 12 is, for example, mounted on the patient's face-facing side of a support frame 32 located at the top of a support column 31. Its vertical position can be adjusted to match the patient's head position by moving the support frame 32 vertically along the height direction of the support column 31. Furthermore, the second digital camera 12 is designed to be vertically displaceable (parallel to the z-axis) from its initial position, while maintaining the camera optical axis (parallel to the y-axis), to match the position of the patient's left and right pupils. The position of this movement is recorded relative to the initial position. (Unlike X-ray imaging, the position of the first digital camera 11 can also be adjusted. Therefore, it is simpler to record and reproduce the first and second camera positions separately, relative to their initial positions, rather than adjusting the second camera position relative to the first camera position. As a result, the face and head can always be photographed in the same orientation using the same coordinate system.)

[0129] Alternatively, by positioning the second digital camera 12 on the same optical axis and along the midline, and selecting a camera at the desired position at the height of the pupil or eye corner, movement can be eliminated or minimized. Furthermore, the second digital camera 12 does not necessarily have to be on the midline; the same effect can be achieved by positioning two cameras symmetrically around the midline. In this case, the width between the left and right camera positions can be adjusted, and the centers of the left and right camera positions can be moved and adjusted parallel to the midline in the left-right direction (y-axis direction). This allows for diverse frontal positioning, such as in cases where there is a difference between the centers of the left and right eyes and the midline of the face, or in cases where the left and right eyes are asymmetrical. In this case as well, by regularly positioning multiple pairs of cameras symmetrically and in the vertical direction, vertical and horizontal movement adjustments can be eliminated or minimized by selecting the appropriate camera.

[0130] Furthermore, by deploying and using both a midline and a pair of left and right cameras, the midline camera can be used to identify characteristic points that constitute the midline other than the eyes, aligning the midline of the face (left-right orientation), and the left and right pair of cameras can be used to align the height of the eyes, allowing the face's up-down orientation to be positioned separately from the optimal viewpoint direction.

[0131] Furthermore, a one-way mirror 15 is positioned vertically in front of the second digital camera 12, displaying the patient's head position from the front. The one-way mirror displays a horizontal reference line and a midline based on the optical axis of the second digital camera 12, and moves in conjunction with the second digital camera 12 as its position moves and is adjusted vertically (it does not move horizontally). This makes it possible to make the operator's viewpoint and the patient's viewpoint the same, allowing both the operator and the patient to more accurately confirm instructions regarding the head position and the content of those instructions, and to adjust the head position accordingly.

[0132] In this embodiment as well, at least two digital cameras, a first digital camera 11 and a second digital camera 12 that are orthogonal to each other, are used to accurately capture the front and side views of the patient, and to perform high-precision positioning of the patient's head in the imaging space of the CT head imaging device 30 in accordance with the imaging coordinate system.

[0133] During positioning, the first digital camera 11 is positioned parallel to the x-axis of the CT imaging coordinate system, but not on the x-axis itself. It is positioned at a location corresponding to the external auditory canal, tragus, etc., and therefore does not overlap with the X-ray irradiation port. For this reason, if the first digital camera 11 does not interfere with X-ray imaging, it is positioned on the X-ray irradiation unit 35, parallel to the X-ray irradiation port. However, if the first digital camera is positioned in a location that interferes with X-ray imaging, the X-ray irradiation unit may be extended as shown in Figure 15, and the first digital camera may be positioned at an angle θ. In this case, during camera imaging, the first digital camera 11 is positioned parallel to the x-axis of the CT imaging coordinate system, and the second digital camera 12 is positioned on the y-axis. During X-ray imaging, the arm rotates by an angle θ to a position where the X-ray imaging axis becomes the x-axis, and X-ray imaging can be started. Alternatively, X-ray imaging may be started from the camera imaging position, and during image processing, the x and y axes may be corrected by calculation by an angle θ to use as the imaging coordinates.

[0134] The head positioning standard device may further include a third digital camera 21 and a fourth digital camera 22, and in addition to the head positioning standard, it may be configured to allow confirmation and positioning of the patient's posture (body axis) during imaging using the viewpoints of the digital cameras from two orthogonal directions, similar to the head position. A fifth digital camera 23 for capturing the foot position may also be included.

[0135] Specifically, the first digital camera 11 is provided with a mounting plate 39 that extends vertically downward, and the third digital camera 21 is positioned on this mounting plate 39 so as to be displaceable vertically. The optical axis of the lens of the third digital camera 21 is an optical axis that extends parallel to the optical axis of the lens of the first digital camera 11.

[0136] Alternatively, the third digital camera 21 may be positioned on a support column 40 that extends vertically upward from a leg portion 38 that extends horizontally along the floor from the lower end of the support column 31, such that its camera lens optical axis is parallel to the patient direction parallel to the X-ray imaging axis on a vertical reference plane passing through the X-ray imaging axis.

[0137] Furthermore, the position where the patient stands is defined by legs 37 and 38 that extend horizontally from the lower end of the support column 31 along the floor. At the tip of the leg 37, at an angle of -90° in a plan view, the support column 40 is erected vertically. A fourth digital camera 22 is held on the upper part of the support column 40 so as to be displaceable vertically. The lens optical axis of the fourth digital camera 22 extends horizontally and toward the center (origin) in a plan view. Multiple third digital cameras 21 and 22 may be arranged vertically. This makes it possible to eliminate or minimize vertical movement adjustment by selecting the desired camera position.

[0138] Furthermore, a fifth digital camera 23 is attached to the lower part of the support column 39. The optical axis of the lens of the fifth digital camera 23 is oriented diagonally downward and forward.

[0139] Although not shown in the diagram, the third digital camera 21, the fourth digital camera 22, and the fifth digital camera 23 are connected to a third monitor 27, a fourth monitor 28, and a fifth monitor 29, respectively, for displaying the images captured by each digital camera 21, 22, and 23.

[0140] The method for positioning the head prior to CT imaging in the CT head imaging apparatus 30 incorporating the head positioning standard device shown in Figures 14 and 15 is substantially the same as the method for positioning the head in the head X-ray standard imaging apparatus 1 shown in Figures 8 to 10. The only difference is that in head positioning, the position of the rotating arm 34 is fixed with the first digital camera 11 at the 0° position in a plan view.

[0141] Therefore, the specific steps of (1) foot positioning, (2) lateral body axis positioning, (3) posterior body axis positioning, (4) lateral positioning, (5) anterior positioning, and (6) recording are the same as described above, so redundant explanations will be omitted.

[0142] Figure 16 is a perspective view showing an example configuration of a magic mirror 15 (see Figures 1, 3, 8, 9, 10, 14, and 15) used in a head positioning standard device according to an embodiment of the present invention.

[0143] The magic mirror 15 may be formed from a transparent glass plate 150 with a thickness of 3mm to 5mm and a front view that is, for example, a vertically elongated rectangle. A thin layer of silver plating 151 is applied to the back of the glass plate 150. Furthermore, a front horizontal reference line H0 extending horizontally in the center in the vertical direction and a front vertical reference line V0 extending vertically in the center in the left-right direction are displayed on the front surface of the glass plate 150. In addition, a back horizontal reference line H0′ extending horizontally in the center in the vertical direction and a back vertical reference line V0′ extending vertically in the center in the left-right direction are displayed on the back surface of the glass plate 150.

[0144] In the magic mirror 15, for example, if the reflectivity is 50%, light incident from the front enters the glass plate 150 from the front, and about 50% of it is reflected by the silver plating layer 151 applied to the back of the glass plate 150, passing through the glass plate 150 and exiting from the front. In addition, about 50% of the light that enters the glass plate 150 is not reflected by the silver plating layer 151 applied to the back of the glass plate 150, and passes through the silver plating layer 151 and exits from the back.

[0145] In the magic mirror 15, the front horizontal reference line H0 and front vertical reference line V0 displayed on the front surface of the glass plate 150, and the back horizontal reference line H0' and back vertical reference line V0' displayed on the back surface of the glass plate 150, are designed so that when viewed while facing the magic mirror 15 directly, H0 and H0', and V0 and V0', respectively, completely overlap to appear as a single horizontal reference line H and a single vertical reference line (midline) V.

[0146] The patient faces a magic mirror 15 on which the midline (vertical reference) and horizontal reference lines of the face have been drawn, and positions themselves in a frontal orientation that they are satisfied with. The operator, at the height of the horizontal reference line and from a fixed viewpoint direction from a camera positioned based on the midline (vertical reference line), confirms the symmetry of the left and right sides of the patient's face as it faces the magic mirror 15. From an anatomical and clinical standpoint, the operator guides the patient's head position and confirms with the patient until a frontal orientation that is satisfactory to both the patient and the operator can be finally positioned. Then, based on the positional relationship between the frontal and lateral maxillofacial camera images taken from a fixed viewpoint direction based on that reference plane and the reference plane, the same head position can be repeatedly positioned and reproduced.

[0147] The magic mirror 15 of this embodiment can improve the accuracy of the patient's head orientation when facing the magic mirror 15 in a frontal head position.

[0148] As shown in Figure 17(A), when the patient is facing the horizontal reference lines H0 and H0' of the magic mirror 15 in the correct position, the horizontal reference lines H0 and H0' overlap and appear as a single line. However, if the patient's viewpoint is shifted upward or downward, the horizontal reference lines H0 and H0' appear as two separate lines (double).

[0149] Furthermore, as shown in Figure 17(B), when the patient is facing the vertical reference lines V0 and V0' of the magic mirror 15 in the correct position, the vertical reference lines V0 and V0' overlap and appear as a single line. However, if the patient's viewpoint is shifted to the right or left, the vertical reference lines V0 and V0' appear as two lines (double).

[0150] The operator's viewpoint can be determined three-dimensionally using the camera, orthogonal directions from the front and side, as well as horizontal and vertical reference lines, allowing for precise positioning of the patient's head. On the other hand, the patient can only see the frontal position reflected in the magic mirror 15, meaning that control over the orientation viewed from the side is insufficient.

[0151] Therefore, by adjusting the height and orientation of the patient's face so that the displayed horizontal line does not appear doubled, the head position from the side can also be positioned more accurately. The operator can also adjust the height of the magic mirror 15 equipped with a camera on the horizontal reference plane so that the patient is in a natural posture and head position at a height where the line does not appear doubled. From the next time onward, the same frontal orientation can be reproduced more accurately and quickly by having the patient determine the frontal position based on the height.

[0152] Similarly, by displaying the vertical reference line (midline) in three dimensions, it becomes possible to determine and reproduce the left-right orientation and position of the face based on how it appears.

[0153] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.

[0154] This application corresponds to Japanese Patent Application No. 2020-151642, filed with the Japan Patent Office on September 9, 2020, and the full disclosure of this application is incorporated herein by reference. [Explanation of symbols]

[0155] 1. Head X-ray standard radiography system 2, 35 X-ray irradiation section 3, 36 X-ray detection unit 5, 14, 24, 31, 40 posts 6 bases 7 Foot position display Arms 8, 81, 82 11. First Digital Camera 12. Second Digital Camera 13. First Monitor 15 Magic Mirror 16. Second monitor 21 Third Digital Camera 22. 4th Digital Camera 23. Fifth Digital Camera 25 Auxiliary Arm 26 Auxiliary support 27 Third Monitor 28. Monitor No. 4 29. Fifth monitor 30 CT Head Imaging System 32 support slots 33 Spindle 34 Rotating Arms 35 X-ray irradiation section 36 X-ray detection unit 37, 38 Legs 39 Mounting plate 150 glass plates 151 Silver-plated layer

Claims

1. A head positioning standard method for standardized X-ray radiography of the head, A side positioning slap is used to capture the side view of a patient's head using a first digital camera whose camera optical axis is aligned with the X-ray imaging axis for capturing a side view of the patient's head placed in the imaging space, and to display a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera on a first monitor together with the captured side view image of the patient's head. The method includes a front positioning step in which a second digital camera, having a horizontal camera optical axis that forms a 90° angle in a plan view with the camera optical axis of the first digital camera and is positioned in the shooting space toward the head and face of the patient, is used to capture the head and face of the patient, and a second horizontal reference line and a second vertical reference line determined by the camera optical axis of the second digital camera are displayed on a second monitor together with the captured image of the head and face of the patient, In the lateral positioning step, while observing the display on the first monitor, the vertical position of the first digital camera is adjusted along with the X-ray imaging axis so that the intersection of the first horizontal reference line and the first vertical reference line, determined by the camera optical axis of the first digital camera, becomes the center of the patient's external auditory canal, and the anterior-posterior position of the patient's head is adjusted with the patient's instructions. In the front positioning step, while viewing the display on the second monitor, the vertical position of the second digital camera is adjusted so that the second horizontal reference line passes through the center of the patient's left and right eyeballs, and the patient is instructed to adjust the vertical tilt of the head and face, and the left and right tilt of the head and face to make the height of the left and right eyes equal, and the patient is instructed to adjust the left and right orientation of the head and face so that the second vertical reference line passes through the center of the patient's left and right eyes, A magic mirror is positioned in front of the second digital camera to reflect the patient's head position, and the magic mirror is configured to move up and down together with the up and down movement of the second digital camera. The magic mirror displays the second horizontal reference line and the second vertical reference line, which are determined by the optical axis of the second digital camera. The patient, while looking at their own face reflected in the one-way mirror, adjusts their head position according to the photographer's instructions, referring to the second horizontal reference line and the second vertical reference line displayed on the one-way mirror. A head positioning standardization method, comprising a recording step of recording the head side image associated with the first horizontal reference line and the first vertical reference line, and the head face image associated with the second horizontal reference line and the second vertical reference line, after the adjustments in the side positioning step and the front positioning step have been completed and head positioning is complete, by pressing the shutters of the first digital camera and the second digital camera, and recording the height positions of the first digital camera and the second digital camera.

2. A method for standard head X-ray imaging, characterized in that, after completing the recording step described in claim 1, the first digital camera is moved away from the X-ray imaging axis and X-ray irradiation is performed.

3. A standard method for head positioning for X-ray CT head imaging, A side positioning step involves using a first digital camera, which is provided at one end of a rotating arm capable of rotating in a horizontal plane around a pivot axis, to capture the side of the patient's head using a first digital camera that has a horizontal camera optical axis directed toward the side of the patient's head in the imaging space, and displays a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera on a first monitor together with the captured image of the patient's side of the head; The method includes a front positioning step in which a second digital camera, having a horizontal camera optical axis that forms a 90° angle in a plan view with the camera optical axis of the first digital camera and is positioned in the shooting space toward the head and face of the patient, is used to capture the head and face of the patient, and a second horizontal reference line and a second vertical reference line determined by the camera optical axis of the second digital camera are displayed on a second monitor together with the captured image of the head and face of the patient, In the lateral positioning step, while observing the display on the first monitor, the vertical position of the first digital camera is adjusted so that the intersection of the first horizontal reference line and the first vertical reference line, determined by the optical axis of the first digital camera, is at the center of the patient's external auditory canal, and the patient is instructed to adjust the anterior-posterior position of their head. In the front positioning step, while viewing the display on the second monitor, the vertical position of the second digital camera is adjusted so that the second horizontal reference line passes through the center of the patient's left and right eyeballs, and the patient is instructed to adjust the vertical tilt of the head and face, and the left and right tilt of the head and face to make the height of the left and right eyes equal, and the patient is instructed to adjust the left and right orientation of the head and face so that the second vertical reference line passes through the center of the patient's left and right eyes, A magic mirror is positioned in front of the second digital camera to reflect the patient's head position, and the magic mirror is configured to move up and down together with the up and down movement of the second digital camera. The magic mirror displays the second horizontal reference line and the second vertical reference line, which are determined by the optical axis of the second digital camera. The patient, while looking at their own face reflected in the one-way mirror, adjusts their head position according to the photographer's instructions, referring to the second horizontal reference line and the second vertical reference line displayed on the one-way mirror. A head positioning standardization method, comprising a recording step of recording the head side image associated with the first horizontal reference line and the first vertical reference line, and the head face image associated with the second horizontal reference line and the second vertical reference line, after the adjustments in the side positioning step and the front positioning step have been completed and head positioning is complete, by pressing the shutters of the first digital camera and the second digital camera, and recording the height positions of the first digital camera and the second digital camera.

4. A head positioning standard method according to claim 1 or 3, When performing head positioning again on the same patient, In the lateral positioning step, Set the height of the first digital camera to the height position recorded in the previous positioning. The lateral view of the patient's head captured by the first digital camera, along with the first horizontal reference line and the first vertical reference line, is displayed on the first monitor. The previously recorded lateral view of the head, the first horizontal reference line, and the first vertical reference line are read out and displayed overlaid on the display on the first monitor. The patient is instructed to adjust the front-to-back position of their head so that the intersection of the first horizontal reference line and the first vertical reference line, determined by the optical axis of the first digital camera, is at the center of the patient's external auditory canal, and so that the outline overlaps with the previous image. In the front positioning step, The height of the second digital camera is set to the height recorded in the previous positioning, and the height of the magic mirror positioned in front of the second digital camera is set to a height corresponding to the height set by the second digital camera. The head and face image of the patient captured by the second digital camera, along with the second horizontal reference line and the second vertical reference line, are displayed on the second monitor. At the same time, the previously recorded head and face image, second horizontal reference line, and second vertical reference line are read out and displayed overlaid on the display on the second monitor. The patient is instructed to adjust the vertical tilt of the head and face to make the height of the left and right eyes equal, adjust the horizontal orientation of the head and face, and adjust so that the contours overlap with the previous image. A head positioning standardization method, which includes the patient adjusting their head position according to the photographer's instructions by looking at their own face reflected in the one-way mirror and referring to the second horizontal reference line and the second vertical reference line displayed on the one-way mirror.

5. The head positioning standard method according to claim 4, further comprising a recording step of recording the head side image associated with a first horizontal reference line and a first vertical reference line, and the head face image associated with a second horizontal reference line and a second vertical reference line, after the adjustments in the side positioning step and the front positioning step have been completed and head positioning is complete, by pressing the shutters of the first digital camera and the second digital camera, and recording the head side image associated with a first horizontal reference line and a first vertical reference line, and recording the height positions of the first digital camera and the second digital camera.

6. The magic mirror has a second horizontal reference line and a second vertical reference line on the front surface of the magic mirror, and a second horizontal reference line and a second vertical reference line on the back surface of the magic mirror. A head positioning standard method according to any one of claims 1 to 5, characterized in that the patient's head position is adjusted when the second horizontal reference line on the front and the second horizontal reference line on the back overlap to appear as a single line, and the second vertical reference line on the front and the second vertical reference line on the back overlap to appear as a single line.

Images