• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A MULTI-FUNCTIONAL MULTI-FUNCTIONAL DENTAL X-RAY IMAGING SYSTEM FOR INDIVIDUAL SENSOR AND METHOD A multi-functional extra-oral dental X-ray imaging system includes a conventional X-ray source and manipulator to control X-ray source movement by translation and rotation, an X-ray imaging device that produces multiple frames in real time and at least two different exposure profile programs, while one of these profiles produces a standard panoramic image and one second of such profiles produces a slice at an angle or across the panoramic image. A third exposure profile program produces a substantially linear projection of the human skull by combining two linear projections, one towards the right and one towards the left of the head. The sensor is a direct linear conversion, preferably operating in frame mode and producing more than 100 fps.
    公开号:BR112012002128B1
    申请号:R112012002128-1
    申请日:2010-06-18
    公开日:2020-12-01
    发明作者:Spartiotis Konstantinos；Pantsar Tuomas；Lohman Henrik Viking
    申请人:Oy Ajat, Ltd.；
    IPC主号:
    专利说明:

    Reference to Related Patent Applications
    [001] This patent application is a continuation in part of US patent application serial number 12 / 134,578 filed on June 6, 2008, which is a continuation in part of prior co-pending US patent application No. series 12 / 076,039 filed on March 13, 2008. The entire content of each of these patent applications is hereby expressly incorporated by reference. Background of the invention
    [002] The present invention relates to the field of extra-oral dental imaging systems. More specifically, the present invention relates to panoramic dental X-ray imaging systems and dental X-ray imaging systems by computed tomography ("CT"). Description of the Related Art
    [003] Digital extraoral dental X-ray imaging systems can be divided into two main categories. The first category is planar imaging systems that produce a flat, two-dimensional image. This category includes formation of panoramic, transversal and cephalometric images. The second category consists of so-called volumetric imaging systems that produce three-dimensional images. These are usually called computer tomography or computed tomography (CT) systems.
    [004] Current systems can have one or more modalities so that an individual system can provide both modalities using a panoramic imaging device as well as a volumetric imaging device.
    [005] The image of a planar imaging system has two types of resolution: The spatial resolution of the image along the two axes of the imaging device ("width" and "height" correspondingly) and the resolution in the direction depth (that is, perpendicular to the imaging layer of the imaging device.)
    [006] The spatial resolution depends on the pixel size of the image forming device, the transfer modulation function inherent in the image forming device (ie, the blur function), the accuracy of the characteristics of the mechanical movement and source X-ray images. Usually it is possible to see pixel-sized objects from the image-forming device, that is, an image-forming device with 100 microns of pixel size can resolve objects that are 100 microns wide.
    [007] Flat X-ray imaging systems produce an image that has all the contents of the object to be viewed projected into a single flat image. This means that all features of the object within the field of view are seen in the image regardless of the actual distance from the sensor. In most cases, it is necessary to eliminate the effect of features or objects outside a selected region of interest. For example, in a panoramic image, the shadow of the spine must be eliminated. Depth resolution means how small the area that will have the projection perfectly focused on the image. Other regions outside this area appeared blurry or disappeared completely. The depth resolution mainly depends on the width of the sensor along the direction of movement, the actual movement path and spatial resolution of the imaging device. The difference between depth and spatial resolution depends almost solely on the angular range from which any point on the object is to be viewed in view. The greater the angular range, the better the depth resolution, that is, smaller objects can be resolved in depth. With the above in mind the extra-oral system performing panoramic image formation of the sensor is typically long and small in width, but does not produce any frames and is not able to make cross-sectional slices. The dual purpose extra-oral systems have a second sensor which is a flat panel of some kind with m / n equal to or very close to 1, and where m is the length and n the width of the flat panel. The length and width of flat panels is usually in the range of 5 cm to 20 cm in most extra-oral dental imaging systems.
    [008] Conventional panoramic X-ray imaging systems (“pan”), digitized with some type of, usually, CCD sensor, have been in existence for the past 15 years. Such standard or conventional dental panoramic X-ray imaging systems can also be adapted to include a cephalometric arm ("ceph") that will produce a linear projection of the entire human skull. Most orthodontists use panoramic systems with or without the ceph arm, which is useful, but will typically add significantly to the dentist's cost.
    [009] Advanced pan systems have included a second sensor, which is typically a small flat panel. This is usually a type of CCD flat panel with dimensions from 10 cmA2 to 30 cmA2 (typically). For example, such a system is described in US2006 / 0233301 Al, with two sensors side by side. The first sensor is a panoramic sensor and the second sensor is a flat panel. When the flat panel is used with a CT motion profile that mostly involved rotation by at least 180 degrees, a volumetric 3D image is produced. The second sensor can also be used to produce transverse slice images, that is, images that are approximately at right angles to the panoramic layer with substantially linear movement. Several such systems, with dual sensor, are available on the market today. The addition of a second sensor makes the system much more expensive for doctors. In addition, the ceph arm is still necessary for a doctor who wants to have a ceph image. Therefore, a complete system would require a first sensor to make a panoramic image, a second sensor / flat panel to make transverse slices and / or 3D images and a ceph arm, where the panoramic sensor would be joined as a pressure fitting in these cases where a ceph image is required.
    [010] In addition to the advanced pan systems, there are very expensive dental CT systems, with flat panels of larger area. The flat panels are square and have active areas greater than 100 cmA2. Such systems cost the physician typically in the range of 100 kUSD-200 kUSD. Therefore, the price is prohibitive for most private medical practitioners. Such systems are currently used by implantologists and large clinics. In addition, dental CT systems have the ability to produce all the necessary panoramic images and transverse slices and 3D volumes, but the quality of the basic image or standard panoramic image is much worse than the quality of a panoramic image produced with a pan system. standard digital camera five times cheaper. Thus, the doctor who wants to have transversal slices, 3D images, but also excellent pan images would still have to buy the enormously expensive dental CT system and also a pan system. The reason that dental CT systems do not make good quality pan images is that the flat panels used are larger in an area with a low frame rate that does not exceed 30 fps. At this low speed, the CT system is unable to make a standard pan exposure and the images come out blurry.
    [011] Therefore, there is a problem to be solved, namely, a dental extra-oral X-ray imaging system that can provide at least two different functions, with a simpler and less expensive structure.
    [012] A solution was proposed in application US 11 / 277,530 assigned to the assignee of the present invention. According to 11 / 277,530 a dental extra-oral X-ray image formation system is provided where with a single panoramic profile exposure the system provides a standard panoramic image, several non-standard panoramic layers, cross slices and even 3D images limited volumes. Such a system is obviously unique in that it provides most of the necessary dental images with an individual sensor and a single exposure profile, namely the panoramic profile. However, the inventors of the present invention idealized that in practice the panoramic profile is specifically designed so that the X-ray source and image forming device move along a path in a way that produces optimal panoramic images, but sub-optimal or very blurred or even useless transversal slices (to the panoramic layer) and even worse 3D images. In addition, document 11 / 277,530 makes no reference to the issue of providing a type of ceph image, namely, a linear projection of the human skull or part of the human skull. Summary of the invention
    [013] In accordance with an aspect of the present invention, there is an extra-oral dental X-ray imaging system comprising an X-ray source exposing X-rays to an object to be viewed; a single X-ray imaging device suitable for producing multiple frames during at least part of the exposure, the individual X-ray imaging device has an active area with a long dimension m and a short dimension n with m / n> 1.5 (one point five); manipulator to move along the path the image forming device between consecutive irradiated frames during exposure, the manipulator allowing the X-ray source to move and the image forming device by means of selective translation and selective rotation over the hair minus one rotational axis located between a focal point of the X-ray source and the X-ray imaging device; said extra-oral dental X-ray imaging system having at least one exposure profile program to produce a local 3D volumetric image or an angled slice to a panoramic layer image for a sub-volume of interest, said profile characterized by the fact that during exposure most of the points, in said subvolume of interest, are projected on said X-ray image formation device with an angular interval β, satisfying the ratio β / α> 2, 1, where a is the angle of the X-ray imaging device as seen from the X-ray focal point, i.e., the opening angle of the sensor.
    [014] In the context of the invention, an exposure profile is a path or trajectory along which the X-ray source assembly and image formation are moving in order to expose part or all of the human head to radiation, including the jaws and teeth. An exposure profile does not need to have X-rays emitted continuously where the human head can be exposed only during part of the profile. The X-ray tube can be of an AC or CC type and X-rays can even be emitted in a pulsed manner. The X-ray source and the imaging device can be joined in a geometry fixed to each other or in rare cases the geometry can vary with moving mechanical parts. According to a second aspect of the present invention, there is an extraoral dental X-ray imaging system comprising an X-ray source exposing X-rays to an object to be viewed; an X-ray imaging device suitable for producing multiple frames during at least part of the exposure, the X-ray imaging device has an active area with a long dimension m and a short dimension n with m / n> 1.5 (a point five), manipulator to move along the path the image forming device between consecutive irradiated frames during the exposure, the manipulator allowing the X-ray source to move and the image forming device by means of selective translation and selective rotation on at least one rotational axis located between a focal point of the X-ray source and the X-ray imaging device; said extraoral dental X-ray imaging system having an exposure profile program to produce a substantially linear projection of at least part of said object to be viewed from said profile comprising at least two substantially linear sections. The linear projection is preferably a cephalometric image of the human skull.
    [015] In a third aspect of the present invention, in order to achieve a panoramic projection image as well as a cephalometric projection image with an individual sensor and without the use of a ceph arm, the focal point distance from the ray source X to the imaging device is less than 1.5 m (one and a half meters) and preferably less than 0.7 m (seventy centimeters), and the distance from the imaging device to the face closest to the object / skull to be displayed is not more than 20 cm and preferably not more than 10 cm.
    [016] The present invention discloses a dental extra-oral X-ray imaging system that is multi-functional producing at least one panoramic layer image, but also has exposure profiles that produce transverse slices, namely images corresponding to a slice that is at an angle to a volume of interest in the panoramic layer image. The present invention also describes a system that can, in addition, or alternatively produce a linear cephalometric projection of the human skull or part of the human skull, but use the traditional ceph arm.
    [017] The X-ray source and the image-forming device are preferably assembled so much as a mechanical pi-shaped structure, which under the control of a manipulator will selectively translate and selectively rotate. This can be achieved by, for example, two or more motors, one motor moving in the x direction and the other motor rotating. More preferably, the system has three motors, two of the motors provide translation in the x, y direction and the third motor rotates.
    [018] The combination of motors and a control unit (usually a CPU or EPROM) is termed as the manipulator as it manipulates the movement of the X-ray source and / or the image forming device. The manipulator can be pre-programmed to run different exposure profiles, meaning that different programs correspond to different exposure profiles, and an exposure profile is a path along which the X-ray source and / or image move during an exposure.
    [019] The imaging device is of the type that is linear, with a long dimension m and a short dimension n, such that m / n> = 1.5, and more preferable m / n> 3 and even more preferably m / n> 6. The choice of the imaging device to be rectangular with an elongated linear shape is very important because such an imaging device (sensor) is capable of operating at high frame rates of more than 50 frames per second (“fps”), more preferably greater than 100 fps and even more preferably in the range of 150 fps to 500 fps. With a fast and elongated image forming device, the present invention produces panoramic images of very high quality (because of the high speed), while maintaining a low cost. Preferably, the imaging device is a CdTe-CMOS (Cadmium Telluride - CMOS) or CdZnTe-CMOS (Cadmium and Zinc Telluride). Such an imaging device combines excellent detection efficiency and excellent resolution with high speed.
    [020] A state-of-the-art conventional dental transverse imaging system uses an expensive wide imaging sensor and a mostly linear motion profile with no or very little rotation. The system according to the present invention uses the linear and inexpensive, fast real-time image output device as described above, and moves during exposure to the X-ray source and device for along a path that is a combination of selective translations and selective rotations such that substantially the entire point in the sub-volume of interest is projected on the X-ray imaging device from different angles in an angular range β / α > 2.1, where a is the angle of the X-ray imaging device as seen from the X-ray focal point. In such a way that the frames produced by the image formation device are used by a processor running an algorithm that reconstructs an image of a slice that is at an angle with respect to the panoramic layer.
    [021] Alternatively, or in addition, the linear imaging device and X-ray source can move, in another exposure profile, along an almost linear path projecting a half of the skull onto the imaging device. human, then by repositioning partial translation and partial rotation with respect to the other half of the human skull and then continuing exposure to produce a second substantially linear projection of the second half of the human skull. Then the frames produced by the imaging device during the two substantially linear exposures are combined in a processor using an algorithm to produce a substantially linear complete projection of the human skull, equivalent to or equal to a traditional cephalometric image.
    [022] The advantages of the present invention are many: - Firstly, an individual system with a single linear and inexpensive sensor is used to produce several or different images of functionality required by the practicing dentist. - Panoramic images as well as transverse (panoramic) images and linear projections of the skull are all of excellent quality, without compromising one or the other. - The system is much more compact than conventional sophisticated panoramic systems with a ceph arm or dental CT systems.
    [023] While the preferred imaging device in the preferred embodiments of the present invention is a roughly bonded CdTe to CMOS or roughly bonded COS to direct CMOS conversion, other imaging devices that produce frame with m / n> 1.5 can be used without departing from the scope of the invention. For example, nano phosphor indirect conversion detector can be coupled to CMOS or CCD and used as an imaging device, or scintillators or regular matches can also be used. Alternatively epitaxially grown CdTe and CdZnTe applied in a CMOS, CCD or flat panel can be used. Alternatively, a CCD that produces a frame or other type of CMOS sensors or flat panel can be used.
    [024] In yet another preferred embodiment of the present invention, an extra-oral dental X-ray imaging system is provided to perform a partial CT or partial 3D image of a region of interest for an object: a) a X-ray source for exposing an object to X-rays so that the object can be viewed during exposure; b) a single X-ray imaging device suitable for producing multiple frames of irradiated image during at least part of the exposure; c) a manipulator to move the image forming device and the X-ray source along a path between different positions corresponding to different frames of the image irradiated during the exposure, the manipulator allowing the movement of both the X-ray source as the image-forming device by selective translation and selective rotation on at least one rotational axis located between a focal point of the X-ray source and the X-ray image-forming device; and d) an exposure profile program to produce a partial CT or 3D image for said region of interest, said profile characterized by the fact that the axis of rotation is mobile along a trajectory during at least part of the exposure. Brief Description of the Drawings Figure 1a, is a schematic representation of a standard or conventional panoramic X-ray imaging system according to the state of the art. Figure 1b, is a schematic representation of a standard panoramic program corresponding to a standard panoramic exposure profile, showing the path along which the X-ray source and the imaging device are moving according to the state of the technique. Figure 2a is a schematic representation of a standard or conventional panoramic X-ray imaging system including a ceph arm according to the state of the art. Figure 2b, is a schematic representation of a standard ceph program corresponding to a standard ceph exposure profile, showing the path along which the X-ray source and the imaging device are moving according to the state of the technique. Figure 3a is a schematic representation of a standard or conventional panoramic X-ray imaging system or dental X-ray imaging CT system including a second or separate flat panel sensor according to the state of the technique. Figure 3b, is a schematic representation of a standard flat panel program in an extraoral dental imaging system, corresponding to a standard cross exposure profile, showing the linear path along which the X-ray source and the flat panel imaging device are moving according to the state of the art. Figure 3c, is a schematic representation of a standard flat panel program in an extraoral dental imaging system, corresponding to a standard transverse exposure profile of the prior art, showing the mainly linear path along which X-ray source and flat panel imaging device are moving according to the state of the art. Figure 4 is a schematic representation of a standard flat panel dental CT program corresponding to a standard dental CT exposure profile, showing the path along which the X-ray source and the panel imaging device plane are moving according to the state of the art. Figure 5 is a schematic representation showing the relationship of angles α and β according to the present invention. Figure 6a is a schematic representation of the cross program, corresponding to the cross exposure profile for a volume of interest to produce a cross slice image in accordance with the present invention. Figure 6b is a flow chart of an algorithm used by a processor to reconstruct a cross-sectional image from the frames produced by the imaging device in a dental extra-oral X-ray imaging system according to the present invention. . Figure 7 is a schematic representation of the quasi-linear projection program, corresponding to the linear exposure profile to produce a linear projection image of at least part of a human skull according to the present invention. Figure 8a is a flowchart of an algorithm used by a processor to reconstruct a cephalometric projection image from the frames produced by the imaging device in a dental extra-oral X-ray imaging system according to present invention. Figure 8b shows the geometry for data collection according to the present invention to obtain a linear or cephalometric projection. Figure 8c shows schematically the adjustment of the layers and addition in order to obtain a linear or cephalometric projection according to the present invention. Figure 9a shows an example reconstructable region using a stationary axis of rotation according to the state of the art. Figure 9b shows an example reconstructable region using a non-stationary axis of rotation using a spiral path according to the present invention. Figure 10a shows an example of the size of the reconstructable region according to the present invention. Figure 10b shows an example of the size of the reconstructable region according to the state of the art. Figures 11a and 11b show a flow chart of an example algorithm used to reconstruct the region of interest in accordance with the present invention. Figures 12a, 12b, 12c, 12d show alternative trajectories along which the axis of rotation can move in an exposure profile to perform partial or partial 3D CT of a region of interest with a system according to the present invention. Figures 12e-f illustrate a rotating axis movement effect can also be achieved without physically moving the axis of rotation. Figure 12g illustrates an extra-oral dental X-ray imaging system in relation to the modality of Figures 12e-f. Detailed Description of Preferred Modalities
    [025] Before discussing the preferred embodiments of the present invention, the state of the art will be reviewed.
    [026] In Figure 1a, a state-of-the-art panoramic panoramic X-ray imaging system is shown. A column (1) supports pi-shaped mounting with the X-ray tube (2) at one end and the CCD, line-out CCD sensor (3) at the other. A manipulator inside the column (1) controls the movement of the X-ray tube assembly (2) and the CCD sensor (3). The manipulator usually comprises one or more motors. There are usually one or two engines and, rarely, three engines. A control panel (5) is used to enter the required X-ray exposure values (kV, mA) as well as to choose the panoramic profile. The image is produced, with a digital connection to a personal computer (4).
    [027] The components of a standard panoramic imaging pattern in the state of the art are illustrated in Figure 1b. The X-ray source (401) and the image-forming device (402), usually a CCD sensor, rotate and translate to produce an image of the predetermined focal layer (field) (405), such movement being along the specified trajectory (403). The purpose of this profile (403) is to form a flat image of the predetermined or ideal focal layer (405). The depth resolution varies along the flat image, but it is on the order of 30 millimeters at the beginning and end (molars) of the exposure and is the best, on the order of 3 millimeters, in the middle (404) (anterior teeth) .
    [028] Figure 2a shows schematically a state-of-the-art dental extra-oral X-ray imaging system, which combines panoramic imaging as well as well-known cephalometric imaging. The components of such a system are X-ray source (12), image forming sensor device (13) and mechanical manipulator (11) including a “ceph arm” (16), user controls (15) and a computer or processor (14) to process and view the images. The image-forming sensor device (13) can move between the cephalometric position (Figure 2a) and the panoramic position (Figure 1a) and is commonly referred to as a “pressure fitting” sensor.
    [029] A state-of-the-art standard digital scanning cephalometric system operates with an exposure profile as illustrated in Figure 2b. The X-ray source (12) translates and rotates along a predefined path, profile, (18) while the imaging device (13) moves along the path, profile, (7) while forming the patient's image (19) to form a semi or substantially linear projection of the entire skull across the plane (8). The distance from the focal point of the X-ray source to the image forming device (191) is large to reduce geometric distortion and is in most cases greater than 1.5 m (one and a half meters) and typically between 1.5 m - 2.5 m. Additionally, the sensor is positioned on a separate “ceph” arm (16) (Figure 2a) that extends laterally and takes up a lot of space. This great distance is necessary so that the X-rays are parallel or almost parallel in order to avoid or mitigate the geometric distortion due to the different enlargement of the various parts of the visualized object.
    [030] In the state of the art there are also dental extra-oral X-ray imaging systems with a second sensor which is a square flat panel or just a sensor which is a square flat panel. Such a dual sensor system is shown in Figure 3a, and is intended to produce transverse slices and / or dental CT images. The column (21) supports the pi-shaped assembly of the panoramic CCD sensor (23) and the X-ray tube (22) as before. The panoramic CCD sensor (23) can be replaced by a flat square panel sensor (26). The manipulator inside the column (21) usually has one, two or three motors and deflects in x, y as well as rotates the assembly. A controller, usually digital, (25) adjusts or selects the kV, mA interval as well as selects the various profiles, that is, movement paths. A computer or processor (24) is provided for processing and viewing the images.
    [031] Figure 3b illustrates the classic profile for producing a transverse slice, with an extra-oral dental imaging system using a flat panel according to the state of the art, namely, substantially linear movement. The Figure shows the geometry in the horizontal, XY plane. The movement could also have a component in the z direction (perpendicular to the XY plane in the figure), but the basic idea remains the same. In this case, the angular viewing range β, from a point to be viewed (102), is equal to the opening angle (α) of the sensor, that is, a = β, or in other words β / α = l. The figure illustrates the X-ray source (101), the image-forming device in a first position (103), the point to be viewed (102) and the movement path of both the X-ray source and the device of image formation in a second position (104) which, as can be seen, is linear. The solid line refers to the geometry after the movement and the dashed line before the movement. Due to the large size of the typical square flat panel, the viewing angle β satisfies the ratio given above. The size of a typical flat panel can be 10 cm x 10 cm or 20 cm x 20 cm. In the case of a 20 cm x 20 cm flat panel and with a distance from the focal point to the flat panel it is typically 50 cm, it means that β / α = 1 and β = α = 2xtan-1 (10/50) = 22.6 degrees. This viewing angle is quite sufficient to produce transverse or angled slices of thickness 0.5 mm - 3 mm which is considered a very good resolution in the direction of depth for a transverse slice. Thus, in the case of linearly moving profiles, using flat panels, β / α = 1 always, and since flat panels are large the viewing angle β is usually large enough to produce sufficiently thin transverse slices. The problem to be solved, however, is the following: a) flat panels are expensive, b) although flat panels can make good cross-sectional images unfortunately produce low-resolution panoramic images. This is the reason why systems that aim to offer both panoramic as well as cross-sectional profiles, have two sensors that add complexity and cost to the dental extra-oral imaging system.
    [032] Figure 3c shows the standard cross-sectional exposure profile as is known in the art through the use of a flat panel detector with length m and width n. Such flat panels have a m / n ratio substantially equal to one (i.e., m / n = 1). Usually a flat panel performs a linear scan where β / α = l. There are cases where the size of the flat panel can be 10 cm x 10 cm or as small as 5 cm x 5 cm. In such cases, there is a series of linear scans allowing for a wider viewing angle. This is shown in Figure 3c. According to the state of the art as illustrated in Figure 3c the X-ray source (501) and the imaging device (502) perform a substantially linear translation around the region of interest (504). The path or profile (503) is sufficient to form a flat image (506) which is a transverse slice through the predetermined focal layer (505).
    [033] In any case, even in the smallest panels with dimensions 5 cm x 5 cm, the angle a = 2 x tan-1 (2.5 / 50) = 5.7 degrees. In order to have a nominal transverse slice thickness from 0.5 mm to 3 mm the viewing angle β must be 10 degrees or more. This could mean that β / α = 10 / 5.7 = 1.8 Therefore, in all known cases, cross-sectional image formation is carried out with a square flat panel or almost registration with m / n «1 and with profiles of movement identified with these β / α ^ 1.8 parameters, one is to obtain in the state of the art transverse slices with adequate thickness resolution. The same initial configuration is or can be used to perform 3D volumetric 3D image formation. The problem is, however, that one is still engaging a sensor to perform the panoramic image formation, typically a CCD line output sensor, and a second sensor, a flat panel with m / n approximately equal to one, to make a or more linear scans satisfying the β / α ^ 2.6 ratio.
    [034] A schematic representation of a standard volumetric dental extra-oral X-ray imaging system geometry and movement is illustrated in Figure 4. The purpose of this document is to produce a 3D volume. The X-ray source (301) and the flat panel imaging device (302) with m 'n rotate along a given (circular) path (303) as multiple images of the region of interest (304 ) are captured from the projection (305). These images are then used to reconstruct the conventional horizontal tomographic slice (306) that contains the region of interest. The region of interest is divided into smaller volume elements, voxels. The size of a voxel can be chosen regardless of the pixel size of the imaging device. Normally the voxel is isotropic, that is, the width and height of the voxel are equal, that is, the voxels are square, but the voxel can also have uneven dimensions. Normally, the path (303) is a circular rotation with at least 180 degree angular view range. Also each point in the region of interest must be seen in each image taken during the exhibition. This means that the size of the region of interest is limited by the size of the imaging device. If the condition that the angular vision range β is at least 180 degrees is met, a “perfect” or optimal volumetric reconstruction can be obtained.
    [035] Order 11 / 277,530, reveals an X-ray imaging system where a frame output sensor is used with m / n> 1.5. The sensor is a panoramic sensor and the teaching of this invention is to use such sensor with m / n> 1.5 in an extra-oral dental X-ray imaging system, so that with a single exposure along the profile suitable to produce a panoramic layer one would obtain in addition to the panoramic layer one of: a) transverse slice or b) a 3D volumetric image. Therefore, document 11/277530 teaches a single extra-oral system with an individual sensor and a single profile or exposure. However, in practice the panoramic profile is such that the X-rays come almost parallel to the direction of the transverse slice, and from such a panoramic profile it is extremely difficult or impossible to produce a transverse slice and even more difficult to make a 3D volume.
    [036] The problem to be solved, therefore, is to provide an extra-oral dental imaging system with an inexpensive individual sensor that is capable of producing at least two of a) good quality panoramic images, b) slice images in good quality angle or cross section, c) good quality cephalometric images without the use of an additional "ceph" arm, and d) good quality local 3D volumetric images.
    [037] The inventors of the present invention have found that a cheap linear sensor with frame output mode can be used to produce a good quality transverse slice if a second profile is implemented which translates and rotates the frame mode sensor m / n> = 1.5 along a profile path, this profile defined by an adequate β / α ratio.
    [038] One aspect of the present invention is illustrated in Figure 5. The sensor (203) is preferably a linear CdTe-CMOS or CdZnTe-CMOS linear sensor with preferably long dimension and short dimension n, where typically m «150 mm and« 6 mm , that is, m / n «25. Another linear type of sensors with materials other than CdTe can be used. The sensor is working in frame output mode, typically providing 50 fps-500 fps. The focal point of the X-ray source is (201) and is typically 300 to 600 mm from the sensor. Therefore, in this configuration the angle α is in the range of 0.5 degrees to 1.1 degrees, that is, including the end points 0.5 and 1.1. In order to get good transverse slices, or slices at an angle to the panoramic layer, or a local 3D volumetric image of a region of interest, one must be viewing angles in the range of 10 degrees -15 degrees or more, including the 10 degree endpoint. Therefore, the β / α ratio is at least 15 / 1.1 = 13.6, since the preferred viewing angle range is β = 15 degrees.
    [039] With a profile defined for this reason, the extra-oral image formation system is capable of operating with a single linear and inexpensive sensor and making both panoramic and transverse or angled slices with good resolution, with a layer thickness of less than 5 mm, preferably less than 3 mm and more preferably less than 2 mm. The term “layer thickness” has the meaning of the physical area that is considered to be in focus, that is, an object contained within the “layer thickness” will be visualized with sufficient sharpness or clarity while objects outside the “layer thickness” will be blurred. Robustly one measures the sharpness or lack of sharpness with the Modulation Transfer Function (MTF) and, for example, an MTF of 0.1 (zero point one) or more would indicate a sharp or focused image. The region of interest (205) can contain one or more layers.
    [040] In another mode the CdTe-CMOS sensor (203) has m «150 mm and« 25 mm, that is, m / n «6. In such a case if the distance between the focal point (201) and the sensor ( 203) is again in the range of 30 mm to 600 mm, α is in the range of 2.3 degrees and 4.7 degrees, including the end points of 2.3 and 4.7 degrees. If β is at least 10 degrees then β / α is at least 15 / 4.7 = 3.2
    [041] In a third mode, the length of the sensor m can be 50 mm - 100 mm and the width n «25 mm, that is, m / n« 1.5 or more. In such a case α is in the range again from 2.3 degrees to 4.7 degrees, including the end points of 2.3 and 4.7 degrees. Again this would mean that the ratio of β / α> 3.2 defines a profile that would be suitable for good panoramic and transverse or angled quality for panoramic slices or a local 3D volumetric image of a region of interest. One is able to achieve satisfactory transverse slice or angle thickness even with β = 10 degrees or more in which case β / α> 2.1 according to the present invention.
    [042] The angled slice profile or cross exposure profile or a previously defined 3D volumetric image exposure profile can be used in at least one region of interest in a panoramic layer, but can also be used for each anatomical region of interest, such as the regions of molar and anterior teeth, individual teeth or teeth within a region. An extra-oral dental X-ray imaging system according to the invention provides such angled or transverse slice exposure profiles with respect to the standard panoramic layer. To achieve this ratio of β / α> 2.1 (at least), a substantial rotational component is added by the inventors to extend the range of angular vision, β, beyond the limit of the opening angle of the sensor a. This is illustrated in Figure 5, which shows how substantial rotation is used to increase the viewing angle β. In this figure, the X-ray focal point (201) and the image forming device (203) rotate and translate along the specified path (204) while forming the image of a point (202) in the region of interest (205). The angular viewing range β is therefore much larger than the opening angle a, since a is really small as shown above for a linear or almost linear sensor with m / n> 1.5. The purpose of the image formation process in this case is to form a flat image along the arrow dimension (206). While state-of-the-art systems require a flat panel sensor, which is essentially square, as well as a second linear sensor with an in-line output, the present invention overcomes the state of the art obstacles and provides a capable system with an individual sensor such sensor operating in frame output mode and with m / n> 1.5, said extra-oral system is additionally programmed to have at least two profiles, one for a panoramic layer / image and a second profile for making a cross-section or in angle, said according to profile defined by β / a> 2.1. Therefore, the extra-oral dental X-ray imaging system is multifunctional and economical.
    [043] With increased angular vision range, ie β / a> 2.1, the depth resolution is improved, that is, smaller objects can be better resolved in the depth direction. The greater the range of angular vision β, the better the depth resolution.
    [044] The same extra-oral system as disclosed in the invention is suitable to perform a volumetric image in local 3D. An algorithm for performing angled slice image formation and / or local 3D image formation is provided herein with reference to Figures 6a and 6b.
    [045] A negative aspect of the substantial rotation of the β angle is that the direction of X-rays becomes almost parallel to the direction of the flat image (angled slice) which causes geometric distortion in the image if standard algorithms designed for forming planar image. Such state-of-the-art algorithms are the same as those used in the reconstruction of panoramic layers, and can be referred to as laminography or tomosynthesis. The present invention provides an extra-oral dental imaging system and an algorithm on how to optimally obtain a transverse or angled slice for the panoramic layer.
    [046] The present invention provides an extra-oral dental imaging system and an algorithm that combines the planar and volumetric imaging modalities to form a flat image with better depth resolution along the z direction, without the need to calculate a complete volumetric image, which would need a large and expensive sensor. Additionally, a local 3D volumetric image can be formed from the different planar layers. Figure 6a shows the X-ray source (601), the imaging device (602) moving along the path (603), (606) according to the present invention. The predetermined panoramic layer is (605). As shown in Figure 6a, the preferably angled slice (610) is at right angles to the panoramic layer in the region of interest (604). In many cases the angled slice may be approximately at right angles to the panoramic layer, but preferably 90 degrees ± 20 degrees. In certain implant operations, the slice angle may be different from the transverse direction. In accordance with the present invention, in order to form a transverse or angled slice (610), the following algorithm according to Figure 6b is applied.
    [047] The algorithm is applied to each horizontal tomographic slice separately and the final image, which is a transverse slice or an angled slice, is formed by stacking the selected region of interest on each horizontal tomographic slice vertically.
    [048] Definitions: a) x a vector of voxel values. For each voxel there is exactly one value in the vector. b) y vector of projections. Each pixel in each projection (frame) has exactly one element in the vector. The values correspond to the values of said pixels in the projections. c) W weight matrix. This matrix encodes the geometry of the system so that the projection equation can be expressed in the form y = Wx
    [049] The first step (651) in the algorithm is to form the W weight matrix. The matrix has one line for each pixel in each projection (so the total number of lines is the number of projections x number of pixels detected in a horizontal tomographic slice.). The matrix has one column for each voxel value (that is, the number of columns in the number of voxels in x). Each element in the matrix indicates how much the corresponding voxel contributes to said pixel value of said projection. This step is usually performed on device calibration and is not calculated during normal exposure.
    [050] The second step is to prepare an initial estimated x0 (652) ("assumption") for voxel x values. The initial estimate can be calculated, for example, using the shift-and-add classification algorithm for tomosynthesis. The quality of the initial estimate does not substantially affect the quality of the reconstructed image, but a good initial estimate allows for shorter processing times.
    [051] The third step (653) is to evaluate the current value for x. This is done by calculating the appropriate mathematical error norm, such as the sum of square differences.
    [052] The fourth step (654) is to decide if the error is small enough. If the error is small enough, then the cycle is closed and the image is finished in the sixth step.
    [053] The fifth step (655) is to calculate a new estimate for x so that the error norm is decreased. This can be calculated, for example, by the well-known gradient gradient algorithm. After that, the algorithm continues in the third step.
    [054] The sixth step (656) is to select a voxel line in x to be shown as a line in the final image. There is usually a line that has the best image quality depending on the geometry of the device. In addition, by combining the voxel lines one can form a local 3D image.
    [055] The seventh and final step (657) is to show a line from the final image, such an image being a transverse slice or an angled one.
    [056] In accordance with yet another aspect of the present invention, an extra-oral dental imaging system capable of cephalometric projections, that is, substantially linear, without the need for an external long arm, is provided. This system offers unique advantages over the state of the art, such as the use of an individual sensor to perform panoramic projections as well as cephalometric projections without the expensive external arm.
    [057] A schematic representation of the state of the art cephalometric imaging system is given in Figure 2a. The components of such a system are X-ray source (12), image forming device (13) and mechanical manipulator including a “ceph arm” (16), user controls (15) and a computer or processor (14) to process and display the images. Figure 2b has already been described and shows a profile movement typical of the conventional ceph system shown in Figure 2a.
    [058] According to the invention the cephalometric functionality, or cephalometric profile movement, of a multi-purpose dental extra-oral X-ray imaging system operates as illustrated in Figure 7. A cephalometric projection, which is a Linear projection of the human skull is achieved by one or more linear or substantially linear exposure profiles with the use of an individual sensor that is positioned with respect to the X-ray source in the same location as during the execution of the panoramic exposure profile. The distance (923) between the focal point of the X-ray source (912) and the imaging device (913) must be less than 1.5 m and preferably must be less than 70 cm in order to be able to the same fixed sensor and fixed geometry to also perform the formation of panoramic image. Therefore, the cumbersome “ceph” arm is eliminated and a simple, compact multifunctional extra-oral imaging system is achieved. The X-ray source (912) runs a profile program along its path (917,918,919) and the CdTe-CMOS X-ray and frame output sensor (913) moves along the path (914,915,916) to form a highly anisotropic volumetric image of the region of interest (920). As mentioned earlier, the distance from the X-ray source to the imaging device is small compared to the standard case. The distance (926) between the sensor (912) and the face closest to the skull from the sensor is minimized or ideally reduced as much as reasonably feasible during each of the linear exposure profiles. In this way, one side of the skull is projected with a lack of sharpness or minimal distortion, while the other side is disproportionate and can be corrected or eliminated from the image with further processing. Such a distance (926) should be less than 20 cm, more preferably less than 10 cm and ideally less than 5 cm. According to the present invention, the focal point of the X-ray source at a distance from the imaging device (923) is short compared to prior art solutions. (923) is preferably less than 1.5 m and even more preferably in the range of 30 cm - 70 cm, which is the range used for the formation of panoramic images. Therefore, with a mechanical arrangement the present invention achieves the formation of both panoramic and cephalometric. This saves a lot of equipment space and reduces the need for multiple or removable sensors.
    [059] The voxels in the volumetric image of the region of interest (920) have a small size in the dimension of the image formation (922), but large size in the perpendicular dimension (921).
    [060] The trajectories of the X-ray source and the image forming device are divided into 3 segments: The first exposure (914, 917), non-radial movement (915, 918) during which the X-ray source (912) and the sensor (913) reposition and the second exposure (916, 919). During the two exposure parts the left and right sides of the skull are visualized. The two parts of the profile during which the skull is exposed to radiation are linear or substantially linear as seen in Figure 7. Substantially linear section means that the distance (924) and (925) from the curve to the arch is less than 20 cm, preferably less than 10 cm and even more preferably less than 1 cm. A "section" means a part of the trajectory that is more than 5 cm long in length and therefore long enough to produce data that will be used in the reconstruction for an image to be shown. It should also be noted in this document that other projection profiles with a similar effect can be used. For example, an L-shaped projection profile with two substantially linear sections with a common point. Alternatively one can use only a substantially linear projection and project part or half of the human skull.
    [061] After exposures, a volumetric reconstruction algorithm is used to calculate vertical slices along the imaging direction (922). These vertical slices are then transformed to eliminate the different increase factor of different vertical slices. Finally, the vertical slices are added together to produce a two-dimensional cephalometric image. Although not limited to any specific reconstruction algorithm, such an algorithm for reconstruction is represented in Figures 8a, 8b and 8c.
    [062] First step in the algorithm is data collection (821). In the data collection stage, multiple frames and corresponding X-ray source and image-forming device locations are recorded. The geometry for data collection is illustrated in Figure 8b. The X-ray source (801) illuminates all the different layers (803) in the object. The X-ray imaging device (802) collects the X-rays and forms an image. The different layers (803) have different magnifying factors because of the shape of the beam (804). The different magnifying factors are displayed with double-headed arrows (805). The arrows closest to the X-ray source are shorter while the arrows closest to the imaging device are longer. The image stored by the image-forming device (802) consists of a sum or overlap of all these layers. The next step (822) is to reconstruct the content of each individual layer and form a separate image for each of the layers. The images can be reconstructed, for example, using the algorithm described previously for the cross-sectional image formation. One layer in this document refers to a plane in the voxel field parallel to the image-forming device.
    [063] Then the next step (823) consists of or calculates the magnification factors for each individual layer image.
    [064] Then (824) the individual layer images (831) in Figure 8c are readjusted using a readjustment algorithm (835) such as bicubic interpolation so that the increase factor after readjustment for each individual layer image is the same . After that, there are multiple images with different sizes, but with the same magnification factor.
    [065] The last step (825) is illustrated by Figure 8c and is to accumulate all the readjusted individual layer images (832) using an adder (833) to form the final image (834) which is now an overlay of all the different ones layers, but unlike the data in the original image, the different layers have equal magnification factors. Thus the final image is substantially the same as an image taken with a parallel beam X-ray source or equal to an image taken with a normal taper beam X-ray source with large X-ray source for the distance of the device of image formation and small object for the distance of the image formation device.
    [066] Referring to Figures 9b, 10a, 11a and 11b, another preferred embodiment of the present invention is described. A state of the art dental CT or 3D system has a circle motion path as illustrated in Figure 9a. Both the X-ray generator (source) (160) and the imaging device (detector) (161) move along a fixed path with a stationary axis of rotation. The system usually rotates from 180 to 360 degrees, that is, half a circle to a full circle. Some example beam projections are given as a reference (164). The axis of rotation (162) is fixed and in the middle of the region of interest (163). For example, that is, according to the state of the art as described in US6118842.
    [067] This trajectory produces a reconstructed arc of a cylinder that has a circular projection in the horizontal plane. The diameter of this circle is equal to the width of the imaging device divided by the magnifying factor (assuming 180 degree rotation) or as much as twice the width of the imaging device divided by the magnifying factor if one so called half-beam technique (involving 360 degree rotation) is used. In normal systems with, for example, a 5 cm wide detector this would give as much 2 * 5 cm / 2 = 5 in diameter for the reconstructed cylinder assuming a typical increase factor of 2.
    [068] A necessary condition for perfect reconstruction with state-of-the-art methods assumes that each point within the volume to be reconstructed is seen in each projection or that each point within the volume to be reconstructed is seen in a complete angular range from 0 to 180 degrees. This allows some points not to be seen in some projections as used in the so-called half-beam technique. Figure 10b illustrates this. A path with a fixed axis of rotation (181) is limited to a reconstructable region (182) that is proportional to the width of the detector regardless of how many frames are collected. In accordance with the present invention there is provided a dental extra-oral X-ray imaging system having a mode of operation for the formation of panoramic images and an operation mode for partial CT or 3D imaging of a region of interest. When in panoramic mode the system will operate in a panoramic path and when in partial CT or 3D mode the system will operate in partial TC mode characterized by the fact that the axis of rotation is no longer fixed, as it is in conventional systems (for example, document US6118842), but it moves too. By way of a preferred example, the axis of rotation when in partial CT / 3D mode is moving along a spiral. An example of a spiral path of the axis of rotation is shown in Figure 9b. In this Figure, the X-ray generator (150) and image-forming device (151) move along a circular path, but the axis of rotation (152) moves along a path, which in this graph is a spiral. Other trajectories of the axis of rotation are possible without departing from the scope of the invention. The region of interest (153) and sample beam projections (154) are given as references.
    [069] Figure 10a illustrates how the size of the reconstructable region (172) can be increased using a movable axis of rotation (171). In this Figure the trajectory of the axis of rotation (171) is a spiral, but other forms of curves or paths can be used. According to the present invention the dental extra-oral X-ray imaging system has a way to perform partial or 3D CT of a region of interest through which the axis of rotation moves which allows for unlimited size reconstructable region assuming that enough time is given to cross the desired path. Figures 10a and 10b are on the same scale, and the units of the x, y axis are in meters.
    [070] With reference now to Figures 11a and 11b, example algorithms are provided that can be used to exemplify how data can be collected and how a CT or 3D image can be reconstructed in a system according to the present invention.
    [071] Figure 11a shows a data collection flow chart in accordance with the present invention. A region of interest is chosen by the user (s111). After which the system moves to the starting position (the beginning of the path for the axis of rotation) (s112). Then the X-rays are turned on (s113) and frames are captured (s114) until the exposure is completed (s115). The manipulator in the unit moves the X-ray source, the imaging device and the axis of rotation between capture frames (s116). In practice, the movement is continuous with a continuous X-ray flow, but the system can also use a pulse-type X-ray source and non-continuous movement. After all frames are captured, the X-rays are turned off (s117), the data is reconstructed (s118) and the reconstructed image is shown to the user (s119).
    [072] Figure 11b shows the outline of the reconstruction algorithm flowchart that can be implemented using a CPU, GPU, FPGA or any other programmable device with an adequate amount of memory. First, the counter variables are initialized to point to the first frame (frame # 0) (s121). Then the current estimate for the volume data is projected to fit the frame #i (s122). This is repeated (s123) until all frames have been processed. The counter is increased (s124) to point to the next frame after the current frame has been processed.
    [073] After forwarding all projections (that is, projecting the volume in 3D to 2D frames) have been calculated, the error between the current simulated and collected data is calculated (s125). Then this error is projected back to the volume elements, that is, the contribution of each volume element to the error is calculated (s126). After the rear projection, the estimated volume is updated based on any updated formula, the simplest being moving each volume element in the direction of least error. A more sophisticated update rule such as ART, statistical inversion or conjugated gradient can also be used. The update can also be done on a frame-by-frame basis the update can process the frames in batches. The rear-projection cycle runs until all frames have been processed (s129). The frame counter is positioned at the following frame between iterations (s130).
    [074] The algorithm in Figure 11b is repeated until the estimated volume is accepted.
    [075] The distinct and innovative advantage of the aforementioned invention is that a digital sensor of limited active area can be used as part of the previous system to allow partial CT or partial 3D reconstruction of useful sizes. For example, with a 25 mm (Width) x 75 mm (Height) +6 mm x 75 mm active area sensor and two rotations in an approximate spiral or spiral with a total axis movement of 25 mm (see Figure 10a ), a 50 mm region of interest can be reconstructed as shown in Figure 10a. With three rotations and axis movement in approximately 35 mm, an 80 mm region of interest can be reconstructed (for clarification, Figure 10a shows only the two examples of rotations). Therefore, while in a conventional dental CT system a 25 mm wide detector would only produce 25 mm / 2 (increase) = 12.5 mm of reconstructed volume, in the system according to the present invention the reconstructed volume is four (4 ) times greater with two rotations on an approximate spiral path and is six (6) times greater if three rotations are used. Obviously as one uses more and more rotations to make a larger spiral, the reconstructed volume increases to the limit that one can with a small active detector area to reconstruct the entire object of interest, for example, all the anterior and posterior. Additionally, it should be noted that the utility of this invention can be realized even for small movements of the axis of rotation during the exposure profile. For example, even one or more millimeters of movement of the axis of rotation will be beneficial. The implication of this invention is that sophisticated extraoral dental X-ray imaging systems use an individual sensor with panoramic exposure mode and partial CT / 3D exposure mode to provide excellent image quality, reconstructed CT size / 3D volume enough at economical prices. Such systems serve orthodontists who care about high-quality panoramic images as well as implantologists and surgeons who need high-quality CT and 3D images. Preferably the detector is a CdTe-CMOS or CdZnTe-CMOS detector that has distinct advantages in terms of reading speed, sensitivity and sharp image formation due to the fact that X-rays are converted directly to the electronic signal. Other detector technologies can be used such as scintillators attached to CCDs or CMOSes, flat panels, etc.
    [076] According to another aspect of the present invention, the dental extraoral X-ray imaging system is configured to perform a partial CT or CT exposure characterized by the fact that the line connecting the focal point of the ray source -X and the central part of the detector is tangential or approximately tangential to the trajectory of the axis of rotation during exposure, or within a range of ± 45 degrees from the tangential to the trajectory. This is illustrated in Figure 12a, where the line connecting the midpoint of the imaging device (1901) to the focal point of the X-ray source (1902) is tangential in that part to the path along which the axis of rotation is moving, but as mentioned there it can also be a deviation from the tangential in the range of ± 45 degrees. This exposure profile allows the size of the region to be reconstructed to expand as the axis of rotation moves along the spiral. The position of the X-ray source and the detector can be changed without departing from the scope of the invention.
    [077] Although preferred modalities have been given and described with respect to the Figures mentioned above, the scope of the invention covers any situation where the axis of rotation is moving during partial CT exposure or CT exposure. The trajectory of the axis of rotation may in fact be an approximate spiral or deformed spiral, or as exemplified in Figures 12b, 12c and 12d, it may comprise part of a circle, a circle or multiple circles depending on how large the volume one wants to reconstruct (Figure 12b), it can be an “S” shaped path (Figure 12d), an “8” shaped path (Figure 12c).
    [078] The effect of moving the axis of rotation can also be achieved without physically moving the axis of rotation, but instead provide additional manipulator (s) to move the image device and / or the source of X-rays with respect to the rotational axis / axes of the system. This is illustrated in Figures 12e and 12f. Figure 12e illustrates the normal system with the image formation device (2001), X-ray source (2002), rotation axis (fixed or moving) and the object to be formed image (2004). The geometry of the image forming device and the X-ray source are fixed with respect to the rotational axis. The rotational axis can be fixed or moved, but the Figure illustrates the case of a fixed rotational axis for simplicity.
    [079] Figure 12f illustrates this aspect of the invention. The geometry of the image forming device and the X-ray source is changed with respect to the rotational axis during exposure. Also the relative geometry of the imaging device and the X-ray source can change to further increase the field of view. The only limitation being that the X-ray beam emitted by the X-ray source needs to be captured by the image forming device.
    [080] There are two points in the exhibition illustrated in Figure 12f. The first point includes the image-forming device (2021a), the X-ray source (2022a), the axis of rotation (2023) and the object to be viewed (2004). The second point in the exposure (or in time has different relative geometry. The relative geometry of the imaging device (2021b) and the X-ray source (2022b) have been changed with respect to the axis of rotation (2023).
    [081] This change in relative geometry creates a virtual rotational axis (2025) that moves along a curve (2026) which in the case of Figure 12f is a spiral even when any other curve mentioned above is suitable. The final effect of this is that the rotational axis can be fixed while still obtaining similar results to expand the field of view as in other aspects of the invention.
    [082] Accordingly, therefore, with this aspect of the present invention an extraoral dental X-ray imaging system is provided as illustrated in Figure 12g, to perform a partial CT or partial 3D image of a region of interest. an object comprising: a) an X-ray source (2102) to expose an object to X-rays so that the object can be viewed during exposure; b) an X-ray imaging device (2101) suitable for producing multiple frames of irradiated image during at least part of the exposure; c) a manipulator (2105) to move the image forming device and the X-ray source along a path between different positions corresponding to several frames of the image irradiated during the exposure, the manipulator allowing the movement of the source of rays -X and the image forming device by selective translation and selective rotation on at least one rotational axis (2106) located between a focal point of the X-ray source and the X-ray image forming device; and any of the following d) additional manipulator (2103) to translate or rotate the imaging device during at least part of the exposure with respect to the rotational axis of the system e) additional manipulator (2104) to translate or rotation of the X-ray source during at least part of the exposure with respect to the rotational axis of the system
    [083] The movement of the image-forming device and the X-ray source must be synchronized so that the X-ray beam originating from the X-ray source is captured by the image-forming device.
    [084] The manipulator for moving the X-ray source can include the translation and rotation of the X-ray source, the translation and rotation of the collimator or the translation and rotation of any component that causes the X-ray beam translation is done.
    权利要求:
    Claims (4)
    [0001]
    1. Extra-oral dental X-ray imaging system, to perform a partial CT or partial 3D image of a region of interest for an object, the system comprising: a) an X-ray source (2102) for exposing an object to X-rays so that the object can be viewed during exposure, b) an X-ray imaging device (2101) suitable for producing multiple frames of irradiated image during at least part of the exposure; and c) a manipulator (2105) for moving the image forming device and the X-ray source along a path between different positions corresponding to different frames of irradiated image during exposure, the manipulator allowing movement of both the source of X-rays and the image-forming device by selective translation and selective rotation on at least one rotational axis (2106) located between a focal point of the X-ray source and the X-ray image-forming device; characterized in that it further comprises d) an additional manipulator (2103) for translating or rotating the image forming device during at least part of the exposure with respect to the rotational axis; and e) additional manipulator (2104) to translate or rotate the X-ray source during at least part of the exposure, with respect to the rotational axis.
    [0002]
    2. Extra-oral dental X-ray imaging system, according to claim 1, characterized in that the additional manipulators are configured to create a virtual rotational axis (2025) adapted to move along a curve ( 2026) during the exhibition.
    [0003]
    3. System according to claim 2, characterized by the fact that at least one rotational axis (2106) is fixed.
    [0004]
    4. System according to claim 1, characterized by the fact that the movement of the imaging device and the X-ray source are adapted to be synchronized so that the X-ray beam produced by the X-ray source is captured by the imaging device.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012002128B1|2020-12-01|multi-functional extra-oral dental x-ray imaging system of individual sensor
    US9907520B2|2018-03-06|Digital tomosynthesis systems, methods, and computer readable media for intraoral dental tomosynthesis imaging
    US7715526B2|2010-05-11|Single sensor multi-functional dental extra-oral x-ray imaging system and method
    KR100929357B1|2009-12-03|Dental extraoral x-ray imaging system and method
    US7715525B2|2010-05-11|Single sensor multi-functional dental extra-oral x-ray imaging system and method
    ES2865066T3|2021-10-14|Dental Imaging with Photon Count Detector
    US10390776B2|2019-08-27|Three-dimentional serial focused intraoral digital tomosynthesis scanner and controlling method thereof
    WO2013095706A1|2013-06-27|Dental imaging with photon-counting detector
    同族专利:
    公开号 | 公开日
    BR112012002128A2|2018-03-13|
    US8306181B2|2012-11-06|
    ES2626622T3|2017-07-25|
    US20100034340A1|2010-02-11|
    WO2011012940A1|2011-02-03|
    KR101603993B1|2016-03-16|
    EP2419018B1|2017-03-22|
    BR112012002128B8|2021-06-22|
    EP2419018A1|2012-02-22|
    KR20120035909A|2012-04-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4149079A|1976-07-14|1979-04-10|Elscint, Ltd.|Method of and means for scanning a body to enable a cross-section thereof to be reconstructed|
    JPS5746853B2|1976-07-15|1982-10-06|
    DE3017494A1|1980-05-07|1981-11-12|Siemens AG, 1000 Berlin und 8000 München|RAY DIAGNOSTIC DEVICE|
    US4637040A|1983-07-28|1987-01-13|Elscint, Ltd.|Plural source computerized tomography device with improved resolution|
    EP0608237B1|1991-06-20|1996-10-16|Board Of Regents, The University Of Texas System|Method and apparatus for computing tomographic and panoramic scans|
    US7136452B2|1995-05-31|2006-11-14|Goldpower Limited|Radiation imaging system, device and method for scan imaging|
    JP3807833B2|1996-12-10|2006-08-09|株式会社モリタ製作所|X-ray equipment|
    FI104944B|1998-06-26|2000-05-15|Planmeca Oy|Methods, equipment and imaging mode for tomography imaging|
    US6496557B2|2000-02-09|2002-12-17|Hologic, Inc.|Two-dimensional slot x-ray bone densitometry, radiography and tomography|
    FI116269B|2000-02-18|2005-10-31|Ge Healthcare Finland Oy|Method for imaging the head region|
    EP1551302B1|2002-07-25|2012-02-08|Gendex Corporation|Real-time digital x-ray imaging apparatus and method|
    DE10313110A1|2003-03-24|2004-10-21|Sirona Dental Systems Gmbh|X-ray device and X-ray sensitive camera|
    US7330763B1|2003-04-30|2008-02-12|Advanced Neuromodulation Systems, Inc.|Method for securing the operating system in a handheld medical device and apparatus|
    JP4594783B2|2005-04-05|2010-12-08|朝日レントゲン工業株式会社|Cone beam X-ray CT imaging system|
    DE112006000869B4|2005-04-11|2017-10-19|J. Morita Mfg. Corp.|Radiography device with overview image function|
    WO2006109806A1|2005-04-11|2006-10-19|J. Morita Manufacturing Corporation|X-ray image sensor and x-ray imaging device using the same|
    US7336763B2|2005-05-02|2008-02-26|Oy Ajat Ltd|Dental extra-oral x-ray imaging system and method|
    US7676022B2|2005-05-02|2010-03-09|Oy Ajat Ltd.|Extra-oral digital panoramic dental x-ray imaging system|
    KR100794563B1|2005-08-08|2008-01-17|주식회사바텍|The combined panoramic and computed tomography photographing apparatus|
    KR100707796B1|2005-08-08|2007-04-13|주식회사바텍|The combined panoramic and computed tomography photographing apparatus|
    KR100766332B1|2005-08-08|2007-10-11|주식회사바텍|The combined panoramic, computed tomography and cephalometric photographing apparatus|CN103096804B|2010-07-13|2017-03-15|达卡拉通信系统株式会社|X-ray tomography is as photographic attachment|
    JP5757660B2|2010-08-11|2015-07-29|学校法人日本大学|X-ray equipment|
    EP3845130A1|2011-12-21|2021-07-07|Carestream Dental Technology Topco Limited|Dental imaging with photon-counting detector|
    JP6066923B2|2010-12-22|2017-01-25|トロフィー|Digital detector|
    US9743893B2|2011-12-21|2017-08-29|Carestream Health, Inc.|Dental imaging with photon-counting detector|
    US8634515B2|2011-04-25|2014-01-21|Vatech Co., Ltd.|Method and apparatus for obtaining panoramic image|
    ITBO20110566A1|2011-10-05|2013-04-06|Cefla Coop|DEVICE FOR THE ACQUISITION OF PANORAMIC RADIOGRAPHIES AND VOLUMETRIC CBCT RADIOGRAPHIES|
    ITBO20110764A1|2011-12-28|2013-06-29|Cefla Coop|DEVICE FOR THE ACQUISITION OF PANORAMIC RADIOGRAPHIES, TELERADIOGRAPHIES AND OPTIONAL VOLUMETRIC CBCT RADIOGRAPHIES|
    KR101850263B1|2014-01-23|2018-04-18|가부시키가이샤 죠부|X-ray inspection apparatus and x-ray inspection method|
    US9730656B2|2014-03-07|2017-08-15|Elwha Llc|Systems, devices, and methods for lowering dental x-ray dosage including feedback sensors|
    US9526468B2|2014-09-09|2016-12-27|General Electric Company|Multiple frame acquisition for exposure control in X-ray medical imagers|
    US10687768B2|2014-09-18|2020-06-23|Vatech Co., Ltd.|X-ray image forming device|
    EP3393364B1|2015-12-23|2019-10-23|Carestream Dental Technology Topco Limited|Method and device for creating a cephalometric image|
    US20190021683A1|2015-12-23|2019-01-24|Trophy|Method and Device for Creating a Cephalometric Image|
    KR102203644B1|2018-09-03|2021-01-15|오스템임플란트 주식회사|Method and Apparatus for generating x-ray image, computer-readable recording medium|
    法律状态:
    2019-01-15| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-07-23| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-04-14| B07A| Technical examination (opinion): publication of technical examination (opinion) [chapter 7.1 patent gazette]|
    2020-08-18| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2020-12-01| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 10 (DEZ) ANOS CONTADOS A PARTIR DE 01/12/2020, OBSERVADAS AS CONDICOES LEGAIS. |
    2021-06-22| B16C| Correction of notification of the grant|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 18/06/2010, OBSERVADAS AS CONDICOES LEGAIS. PATENTE CONCEDIDA CONFORME ADI 5.529/DF, QUE DETERMINA A ALTERACAO DO PRAZO DE CONCESSAO |
    优先权:
    申请号 | 申请日 | 专利标题
    US12/510,346|2009-07-28|
    US12/510,346|US8306181B2|2008-03-13|2009-07-28|Single sensor multi-functional dental extra-oral x-ray imaging system and method|
    PCT/IB2010/001501|WO2011012940A1|2009-07-28|2010-06-18|A single sensor multi-functional dental extra oral x-ray imaging system and method|
    [返回顶部]