JP7078210B2 - Fixed Oral Tomosynthesis Imaging Systems, Methods, and Computer-Readable Medium for 3D Dental Imaging - Google Patents

Description

Detailed description of the invention

Cross-reference with related applications This patent application is the specification of US Provisional Patent Application No. 62 / 333,614 filed May 9, 2016, the contents of which are incorporated herein by reference in their entirety. Claim priority.
[Technical field]
The subject matter disclosed herein relates to radiography. More specifically, the subjects disclosed herein relate to fixed intraoral tomosynthesis systems, methods, and computer-readable media for three-dimensional dental imaging.
[Background technology]
Dental radiography has undergone significant changes over the last few decades. However, the need for imaging methods used for more accurate diagnosis continues to be a high priority. Oral dental x-rays were introduced only one year after X-rays were discovered by X-ray radiation. Since that time, advances in dental imaging techniques have included more sensitive detector techniques, panoramic imaging, digital imaging, and cone beam computer tomography (CBCT). Computer tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and optical techniques are also being considered for dental imaging.

Intraoral radiography is the mainstream of dental imaging. It provides relatively high resolution and limited field image for most routine dental needs. However, as a two-dimensional (2D) imaging mode, this technique suffers from superimposition of overlapping structures and loss of spatial information in depth dimensions. Panorama imaging is a common form of extraoral imaging that visualizes the maxilla, mandible, temporalis-mandibular joint (TMJ) and the entire associated structure within a single image, but with significant geometric distortion. The spatial resolution is relatively low compared to intraoral radiography. CBCT as a three-dimensional (3D) imaging modality is widely accepted in the dental field, especially in surgical planning procedures such as dental implants and orthodontic treatment plans, as well as in the assessment of endodontic and pathological conditions. However, compared to 2DX radiography, there are some drawbacks associated with CBCT, including excessive noise and artifacts from metal dental restorations / instruments, which degrades image quality. .. Compared to 2DX radiography, the time for acquisition, reconstruction, and interpretation is significantly increased, which reduces clinical efficiency and increases financial costs. The amount of ionizing radiation is significantly higher, thereby increasing the radiation load on the patient.

Despite many technological advances, the radiographic diagnostic accuracy of some of the most common dental conditions has not improved over the years and in some cases remains low. Examples include caries detection, root fracture detection, and periodontal loss assessment.

Caries is the most common dental disease. The World Health Organization (WHO) estimates that 60% to 90% of school children and almost all adults have dental caries at some point. If caries lesions are detected early enough (eg, before cavitation), they can be pinched and remineralized by non-surgical means. If the caries lesion goes undetected, it can lead to more serious conditions that may require extensive restoration, endodontic treatment, and in some cases tooth extraction. The detection sensitivity of dental caries has not improved significantly in recent decades. Two-dimensional intraoral radiography is the current gold standard, with sensitivities ranging from 40% to 70% for lesions within the dentin and 30% to 40% for lesions confined to enamel. CBCT does not bring a significant improvement in caries detection. Beam hardening artifacts and patient movement reduce structural sharpness and definition.

Detection of vertical root fracture (VRF) is a clinically important diagnostic challenge and has important implications for tooth management. VRF is considered to be one of the most unpleasant dental conditions associated with endodontic treatment. Overall detection of VRF remains poor. The ability of CBCT to detect early root fractures is limited by its relatively low resolution. In addition, excessive beam hardening, streak artifacts, and noise result in a significant decrease in sensitivity and an increase in false-positive root fracture diagnosis.

Dental radiography provides important information for assessing the prognosis of teeth and making treatment decisions related to periodontal disease. Currently, two-dimensional intraoral radiography is the mainstream of dental imaging. It provides relatively high resolution images with a limited field of view for most routine dental needs. However, this technique is limited by the 2D representation of the 3D object. The result of 2D images is the superposition of overlapping structures and the loss of spatial information in depth dimensions. As a result, important dimensional relationships are obscured, the observed sharpness is reduced, the object of interest is lost, and the pathological contrast is reduced. Panorama imaging, on the other hand, is a common form of extraoral imaging that visualizes the maxillary, mandibular, temporalis and mandibular joints and the entire associated structure in a single scan. It is susceptible to considerable geometric distortion and has a relatively low spatial resolution compared to intraoral x imaging.

These diagnostic challenges demonstrate the clinical need for diagnostic imaging systems with high resolution, 3D capability, reduced metal artifact sensitivity, and reduced radiation load on patients.
Digital tomosynthesis imaging is a 3D imaging technique that provides reconstructed slice images from a series of projected images at a limited angle. Digital tomosynthesis improves the visibility of anatomical structures by reducing visual clutter from the overlaid normal anatomy. Some examples of current clinical tomosynthesis applications include chest, abdominal, musculoskeletal and breast imaging.

In the late 1990s, a variation of tomosynthesis technology, the so-called Tuned Aperture Completed Tomography (TACT), was examined for dental imaging. TACT has significantly improved diagnostic accuracy for many tasks compared to conventional radiography. These improvements included detection of root fractures, detection and quantification of periodontal bone loss, implant site assessment, and assessment of buried third molars. However, the caries results were uncertain.

TACT was not clinically adopted because the technique was not practical for patient imaging. A conventional X-ray tube is a single pixel device in which X-rays are emitted from a fixed point (focal point). The astrophysical x-ray was mechanically moved around the patient to obtain multiple projected images. Reference markers were used to determine the imaging geometry. This process was time consuming (eg, about 30 minutes per scan) and required a high degree of operator skill to achieve image acquisition. The mechanical movement of the X-ray source makes TACT impractical due to the parameters of the imaging geometry and the difficulty of accurately determining long imaging acquisition times. Any relation of TACT for 3D intraoral imaging using a single X-ray source has similar drawbacks and disadvantages.

Extraoral tomosynthesis has been investigated in the study of patients using experimental equipment as well as using CBCT. Extraoral geometry required high radiation doses. Image quality was compromised by out-of-focus crosstalk. Intraoral tomosynthesis using a single mechanically scanned X-ray source to avoid high radiation doses has been described in patent literature, and recent publications have used a single conventional X-ray source and rotating phantom. Is being considered. Unfortunately, the constraints mentioned above for TACT are the same in these methods and are therefore primarily caused by conventional single focus X-ray tubes and therefore have the same spatial resolution as traditional 2D intraoral dental imaging. There is a need for fixed intraoral tomosynthesis systems, methods, and computer-readable media for 3D dental imaging that can rapidly obtain 3D dental images to patients at equivalent radiation doses.
[Outline of the invention]
The subject matter of the present disclosure relates to generating a three-dimensional (3D) tomosynthesis image of an object, particularly an image of a patient's teeth, from one or more two-dimensional (2D) X-ray projection images.

According to one aspect of the subject matter herein, a fixed intraoral tomosynthesis system for three-dimensional (3D) imaging of an object, spatially dispersed, including one or more focal points. A degree of freedom (DOF) device attached to an X-ray source array and a spatially distributed X-ray source array at the first end of the joint arm, targeting the first end of the joint arm. A control unit with a degree of freedom (DOF) device located closest to an object, a power source, and a control electronic device configured to control a spatially distributed X-ray source array. It can be attached to the second end of the joint arm and is connected to spatially distributed X-ray sources through or along the inside of the joint arm via electrical cables and mounted on a wall or surface. Possible, a control unit and an intraoral detector configured to record one or more X-ray projection images, each of which is spatially dispersed. An intraoral detector, a spatially distributed X-ray source array, and a patient generated by X-ray radiation emitted from the corresponding focal point of one or more focal points of the arranged X-ray source array. A collimator disposed between and one or more of spatially distributed X-ray source arrays by coupling a spatially distributed X-ray source array to an X-ray detector. A fixed intraoral tomosynthesis system with a collimator configured to limit X-ray radiation emitted from the focal point to a common area defined by an intraoral detector, also known as an X-ray sensor. , Provided.
The fixed intraoral tomosynthesis system is configured to perform tomosynthesis reconstruction and use a computing platform to generate one or more 3D images using one or more X-ray projection images. Tomosynthesis.

According to another aspect of the subject matter herein, a method for 3D imaging using a fixed intraoral tomosynthesis system, a spatially distributed X-ray source array of fixed intraoral tomosynthesis systems. A step outside the patient's mouth, the spatially distributed X-ray source array comprising one or more spatially distributed focal points on one or more anodes. The X-ray detector holder is a step of placing the X-ray detector inside the patient's mouth using an X-ray detector holder configured for at least one imaging protocol. A plurality of magnets disposed on the first end of the X-ray detector holder, the first end of which is located outside the patient's mouth, with a step to place and a first collimeter plate. In the step of providing a second collimator plate to the first end of the collimator and a second collimator plate to the second end of the collimator, the second collimator plate is an X-ray detector for at least one imaging protocol. The steps to be selected to accommodate one or more aspects of the holder and the spatially distributed X-ray source array and collimator, the second collimator plate to the second end of the collimator. And the step of coupling to the X-ray detector holder via the second collimator plate by coupling onto the first end of the X-ray detector holder and each of the one or more focal points preset. A step of acquiring one or more X-ray projections of a patient's mouth from one or more viewing angles by sequentially activating for radiation dose and X-ray energy, one or more X-rays. The line projection image is two-dimensional (2D), using one or more iterative reconstruction algorithms, one step to acquire, one step to transfer one or more X-ray projection images to the computing platform, and one or more iterative reconstruction algorithms. Steps to reconstruct one or more 3D tomosynthesis images from one or more X-ray projection images and process one or more 3D tomosynthesis images to compute one or more 3D tomosynthesis images. A method is provided that includes displaying on one or more monitors electrically connected to the ing platform.

According to yet another aspect of the subject matter of the present specification, a non-temporary computer-readable medium comprising computer-executable instructions that, when executed by a computer processor, controls the computer to perform a method, the method. Is a step of placing a spatially distributed X-ray source array of a fixed intraoral tomosynthesis system on the first side of an object, or outside the patient's mouth, and is spatially distributed. The X-ray source array contains one or more focal points, a second side of the object, or a patient using an X-ray detector holder configured for the step of placement and at least one imaging protocol. In the step of arranging the X-ray detector inside the mouth of the X-ray detector, the X-ray detector holder includes a plurality of magnets arranged on the first end of the X-ray detector holder, the first of which comprises a plurality of magnets. The end of the is located on the first side of the object, or outside the patient's mouth, with the step to place and the first collimeter plate to the first end of the collimeter and the second collimeter plate to the collimeter. A second collimator plate is selected to accommodate one or more aspects of the X-ray detector holder for at least one imaging protocol, which is a step provided to the second end of the X-ray detector. The provided steps and the spatially distributed X-ray source array and collimator are coupled to the second collimator plate onto the second end of the collimator and the first end of the X-ray detector holder. One by sequentially activating each of one or more focal points for a preset radiation dose and X-ray energy, with the step of coupling to the X-ray detector holder via a second collimator plate. Or a step of acquiring one or more X-ray projections of an object or patient's mouth from multiple viewing angles, where the one or more X-ray projections are two-dimensional (2D), acquisition. Steps to transfer one or more X-ray projections to a computing platform, and one from one or more X-ray projections using one or more iterative reconstruction algorithms. Or the step of reconstructing multiple 3D tomosynthesis images and processing one or more 3D tomosynthesis images and connecting the one or more 3D tomosynthesis images to one or more electrically connected computing platforms. Non-temporary, including steps to display on the monitor Computer readable media are provided.

Some aspects of the subject matter disclosed herein are described above herein and are achieved in whole or in part by the subject matter disclosed herein, while other aspects are in the accompanying drawings. It becomes clearer as the description progresses as it is addressed in the context of, which is best described below herein.

The features and advantages of the subject matter of the present invention will be more easily understood from the following detailed description which should be read in conjunction with the accompanying drawings provided solely as descriptive and non-limiting examples.
FIG. 1 is a perspective view illustrating an exemplary embodiment of an intraoral tomosynthesis system having a fixed link mechanism between an X-ray source and an X-ray detector, as disclosed herein. FIG. 2A is a top view showing a fixed link mechanism between the X-ray source and the X-ray detector of FIG. 1 as disclosed herein. FIG. 2B is a top perspective view showing a receptacle between an X-ray source and an X-ray detector, as disclosed herein. FIG. 3A is a front perspective view illustrating an exemplary embodiment of a geometry calibration device for an intraoral tomosynthesis system according to the disclosure herein, FIG. 3B is a geometry calibration of FIG. 3A according to the disclosure herein. It is a rear perspective view which shows the exemplary embodiment of the apparatus. FIG. 4 is an exemplary image capture showing the process for determining tomosynthesis imaging geometry using the exemplary geometry calibrators of FIGS. 3A-3B, as disclosed herein. 5A, 5B, 5C and 5D are schematics illustrating an exemplary geometry calibrator for an intraoral tomosynthesis system as disclosed herein. 6A, 6B and 6C are schematics illustrating exemplary optical patterns using the geometry calibrators of FIGS. 5A-5D, as disclosed herein. FIG. 7 is a schematic diagram illustrating an exemplary embodiment of a geometry calibrator for an intraoral tomosynthesis system as disclosed herein. FIG. 8 is a schematic system diagram illustrating an exemplary embodiment of a stationary intraoral tomosynthesis system for three-dimensional (3D) dental imaging interfaced with an exemplary computing platform, as disclosed herein. be. FIG. 9 is a fixed intraoral tomosynthesis system for 3D dental imaging according to the disclosure herein, with a joint arm having a degree of freedom device at one end and an electronic device and power supply at the other end. It is a perspective view which shows the exemplary embodiment. FIG. 10 is a perspective view showing an embodiment of an exemplary holder for an X-ray sensor and / or detector as disclosed herein. 11A and 11B are detailed perspective views illustrating an exemplary embodiment of the magnetic coupling of the detector holder of FIG. 10 to the collimator, as disclosed herein. FIG. 12 is a perspective view showing an exemplary embodiment of a collimator having a first X-ray limiting collimator plate and a second X-ray limiting collimator plate according to the disclosure herein. FIG. 13 is a perspective view showing the first X-ray limiting collimator plate of FIG. 12, according to the disclosure of the present specification. FIG. 14 is a schematic of an exemplary collimator collimating an X-ray beam from each focal point to the detector region, as disclosed herein. FIG. 15 is a perspective view of an exemplary embodiment of a degree of freedom device having three degrees of freedom rotation according to the disclosure herein. FIG. 16 is a perspective view illustrating an exemplary embodiment of a linear X-ray source array as disclosed herein. FIG. 17A is a linear X-ray source array for an exemplary embodiment of an X-ray sensor and / or detector such that the scanning direction is substantially perpendicular to the root-crown direction, as disclosed herein. Schematic of the relative orientation, FIG. 17B is an exemplary disclosure of an X-ray sensor and / or detector such that the scanning direction is substantially parallel to the root-crown direction, as disclosed herein. It is a schematic diagram of the relative orientation of a linear X-ray source array with respect to an embodiment. FIG. 18 is a fixed intraoral tomosynthesis method for 3D dental imaging using a fixed intraoral tomosynthesis system, including the creation and display of synthetic two-dimensional (2D) intraoral images, as disclosed herein. It is a schematic diagram using the flowchart of an exemplary embodiment.

The subject matter of the present disclosure relates to fixed oral tomosynthesis systems, methods, and computer-readable media for three-dimensional (3D) dental imaging applications, such fixed oral tomosynthesis systems, methods, and computer-readable media. However, it will be appreciated by those skilled in the art that it may be used for applications other than dental imaging. For example, the system described herein is a stationary digital breast tomosynthesis (s-DBT) system as disclosed in US Pat. No. 7,751,528, which is incorporated herein by reference in its entirety. May be modified in the form of. In particular, the fixed design of the s-DBT system increases the spatial resolution of the system by eliminating image blur caused by the operation of the X-ray tube. Faster scan times are also achieved by integrating with a high frame rate detector to minimize patient movement and uncompressed discomfort. The fixed design of the s-DBT system, which is free of mechanical movement constraints, also allows for wider angle tomosynthesis scans for deeper resolution without changing the scan time.

In some embodiments, the fixed intraoral tomosynthesis systems, methods, and computer-readable media described herein are used for dental imaging applications. In particular, a fixed intraoral tomosynthesis system can be used for intraoral imaging applications using an X-ray detector placed inside the patient's mouth. In another aspect, the fixed tomosynthesis system may be used for extraoral imaging applications using an X-ray detector placed outside the patient's mouth.

In some embodiments, fixed intraoral tomosynthesis systems, methods, and computer-readable media can be utilized in dual energy applications. For example, two complete sets of X-ray projection images can be collected for each object to be imaged. The first set can be collected with the first X-ray energy and the second set can be collected with the second X-ray energy, where the first X-ray energy is the second X-ray. Not like energy. According to one such aspect, two sets of X-ray images are collected at two different X-ray anode voltages and then processed, reconstructed, and subtracted to give specific features such as caries. Emphasize the contrast to. According to another such aspect, at each viewing angle, two projection images can be obtained, one with the first X-ray energy and the other with the second X-ray energy.

Accordingly, the subject matter of the present disclosure provides a fixed intraoral tomosynthesis system, method, and computer-readable medium for 3D dental imaging. According to some embodiments, a fixed intraoral tomosynthesis system, method, and computer-readable medium for 3D dental imaging are an X-ray source and an X-ray detector for placement inside the patient's mouth. And to obtain multiple projections of the ROI of the object in the patient's mouth (eg, teeth) without moving the geometry calibrator and the X-ray source, X-ray detector, or region of interest (ROI). It can include control electronic devices. FIG. 1 shows one such embodiment of the oral tomosynthesis system represented by 100 overall. The system 100 includes an X-ray source indicated by 110 as a whole, an X-ray detector 120, a control unit indicated by 130 as a whole, a collimator indicated by 140 as a whole, and an X-ray detector holder 150. be able to. In some embodiments, the system 100 may be fitted so as to be immobile. For example, the system 100 can be mounted from a ceiling, a wall, or the like. In another aspect, the system 100 may be mobile. For example, the system 100 may include wheels and may be placed on a moving cart, hand truck, stand, or the like. FIG. 1 shows a mobile cart, generally shown by 102, to which the system 100 is mounted, using the mechanical arm, which is generally shown by 104. The mechanical arm 104 may be rotatable and / or axially movable around a pivot or hinge joint to adjust the position of the system 100 around the object to be imaged. Therefore, by using the moving cart 102 and the mechanical arm 104, the system 100 is free to move and rotate for optimal placement with respect to the object. Optionally, the mobile cart 102 may include a rechargeable battery (not shown) capable of supplying power for imaging, whereby an electrical cord and / or wire for powering the system 100. Reduce the need for.

The X-ray source 110 can be configured to direct an X-ray beam (eg, 108 in FIG. 2A) towards a location or location where the ROI of an object (eg, a patient's tooth) is located. The X-ray beam can be directed at its location or location from several different angles. Further, the X-ray source 110, the X-ray detector 120 and the object can be arranged so that the generated X-ray beam is detected by the X-ray detector 120. In some embodiments, the X-ray source 110 is a spatially distributed X-ray source arranged so that the generated X-ray beam is substantially directed at the object and can pass through the ROI of the object. An array (eg, 310 in FIG. 3A) can be provided. In some embodiments, the ROI of the object can vary because different ROIs of the object can be imaged during one or more imaging sessions.

In some embodiments, the X-ray source array of the X-ray source 110 can include a plurality of individually programmable X-ray pixels (eg, 312 in FIG. 3A) distributed as a linear array. Alternatively, the X-ray pixels may be non-linearly distributed along the X-ray source 110, for example, in an arc, a circumference, a polygon, a two-dimensional matrix, or the like. In some embodiments, the X-ray pixels in the array may be uniformly spaced and / or tilted to direct the X-ray beam towards the ROI of the object. In any case, the X-ray pixels may be placed in any suitable position so that the X-ray beam is substantially directed at the object and detected by the X-ray detector 120. In particular, the X-ray source 110 and the X-ray detector 120 can be fixed to each other during irradiation of the object by the X-ray source 110 and detection by the X-ray detector 120. The X-ray source 110 is controlled (eg, by the control unit 130) to be sequentially activated (eg, one pixel is activated at a time) for a given dwell time and a given X-ray dose level. Can be done.

In some embodiments, the X-ray source array of the X-ray source 110 can include, for example, between 10 and 100 pixels, in particular 25 pixels. Each pixel is, for example, XinRay Systems Inc. For example, carbon nanotube (CNT) field emission based cathodes, gate electrodes for extracting electrons, and small regions on the target (eg, anode) of field emission electrons, such as those commercially available from manufacturers. Alternatively, it may include a set of electron focusing lenses for focusing on the focal point (eg, an Ein-Zel type electrostatic focusing lens). In particular, the CNT cathode is a cold cathode and can be instantly switched on and off. By using the CNT cathode in this way, the warm-up time and heat generation of the X-ray source 110 are compared with the conventional vacuum electronic equipment based on the hot cathode (for example, cathode ray tube, microwave tube, X-ray tube, etc.). Can be reduced. Alternatively, each pixel can include a hot cathode, a photocathode, and the like.

In some embodiments, the distance from the pixels to the X-ray source can vary from pixel to pixel if the X-ray source pixels are arranged linearly parallel to the detector plane rather than an arc. To compensate for such fluctuations in the X-ray beam travel distance, the X-ray tube current from each pixel is individually controlled (eg, by the control unit 130) so that the magnetic flux intensity at the phantom surface remains the same. Can be adjusted.

The size of the focal point and / or the X-ray flux generated by each pixel of the X-ray source array of the X-ray source 110 may be adjusted by the control unit 130. The focal point can be in the size range of about 0.05 mm to 2 mm. The system 100 may be designed for an isotropic 0.2 × 0.2 mm effective focal size for each X-ray source pixel. The individual focal size can be adjusted by adjusting the potential (eg, voltage) of the focusing electrode. Incorporating an electrical compensation loop to automatically adjust the gate voltage to maintain a constant preset radiated current to minimize current fluctuations and delays and to reduce pixel-to-pixel variability. Can be done. The area of the CNT cathode can be selected so that a peak X-ray tube current of about 10 mA can be obtained with an effective focal size of 0.2 × 0.2 mm. In particular, by increasing the CNT area and focal size, higher X-ray peak currents of 50-100 mA can be obtained.

In some embodiments, the X-ray detector 120 can be configured for intraoral or extraoral detection of projected images. For example, the X-ray detector 120 can include an intraoral X-ray detector configured to be located inside the patient's mouth and behind the patient's teeth. The X-ray detector 120 can include a high frame rate of about 1 to 100 frames per second (eg, Hertz). The X-ray detector 120 also includes high spatial resolution with pixel sizes in the range of 10 x 10 microns to 200 x 200 microns to detect projected images of objects (eg, teeth in the patient's mouth). You can also do it.

The X-ray detector 120 can be configured to collect projected images of the object from different angles for tomosynthesis. To do so, the control unit 130, which may be housed in the housing 132 of the system 100, is on the region of the X-ray source 110 (eg, on one or more anodes in a vacuum chamber) as described herein. The X-ray source array of electron-radiating pixels spatially dispersed in the area is sequentially activated according to a predetermined irradiation time, radiation dose, and X-ray energy to adjust the intensity of the X-ray flux from each focal point. Can be configured in. The X-ray source 110 can be electronically interfaced with the X-ray detector 120, whereby a projected image is recorded from the radiation generated from each focal point. In particular, the control unit 130 reads the radiation from each focal point directly, reads the X-ray tube current, or reads the cathode current, based on the distance between the X-ray source array of the X-ray source 110 and the object. Can change the intensity of X-ray radiation. In this way, the X-rays delivered to the object from all viewing angles are substantially the same.

In some embodiments, the size of each focal point and / or the X-ray flux produced by the X-ray source 110 can be regulated by the control unit 130. For example, the control unit 130 may have a carbon nanotube area and focal size where the X-ray source 110 has a tube current of up to 100 kVp and up to 10-20 mA for each focal point, and for focal sizes ranging from 0.1 mm to 1.5 mm. Can be adjusted to operate at higher X-ray peak currents of 50-100 mA by increasing. In some embodiments, the control unit 130 can also adjust the individual focal size by adjusting the potential of the focusing electrode. In some embodiments, the control unit 130 incorporates an electrical compensation loop to regulate the gate voltage to maintain a constant preset radiated current to minimize current fluctuations and reduce pixel-to-pixel variability. Can be reduced.

The collimator 140 can be placed between the window of the X-ray source 110 and the detector 120 to limit X-ray radiation to the ROI of the object. In some embodiments, the first end of the collimator 140 can be secured to the X-ray source 110, and the second end of the collimator 140 is foldable and / or tapered in the direction of the detector 120. Can be configured.

In some embodiments, the mechanical fixture (eg, the X-ray detector holder 150) can be attached by connecting the X-ray source 110 to the X-ray detector 120 at a known fixed position. Therefore, the position of the X-ray source 110 with respect to the X-ray detector 120 can always be known and maintained. Alternatively, the position of the X-ray focus with respect to the X-ray detector 120 need not be determined by the physical connection between the X-ray detector 120 and the X-ray source 110. Instead, a geometry calibrator can be used to determine the position of the X-ray source 110 with respect to the X-ray detector 120, thereby detecting the position of the X-ray focal point with respect to the X-ray detector 120.

Next, with reference to FIG. 2A, a more detailed view of the system 100 is shown. In particular, the relationship between the X-ray source 110, the X-ray detector 120, and the X-ray detector holder 150 is shown in more detail. As shown in FIG. 2A, the X-ray detector holders 150 secure the X-ray source 110 to the X-ray detector 120 at a distance known to each other. In some embodiments, the first end of the X-ray detector holder 150 is fixed to the X-ray source 110 and the second end of the X-ray detector holder 150 is fixed to the X-ray detector 120. In some embodiments, the X-ray source array of the X-ray source 110 comprises a plurality of pixels, each of which is located at a known location and set to point inward at a known angle towards the object. Will be done. Therefore, when the X-ray source 110 and the X-ray detector 120 are arranged at a fixed distance from each other, the exact position of the focal point produced by the X-ray source array pixels with respect to the X-ray detector 120 is. It is known.

For example, in FIG. 2A, the X-ray source 110 and the X-ray detector 120 are fixedly separated by the distance D by the X-ray detector holder 150. In this example, the X-ray source 110 comprises a linear X-ray source array and the X-ray source detector 120 is an intraoral detector for placement in the patient's mouth to image the tooth as a whole at 106. It is configured as a vessel. The X-ray detector 120 may be located behind a particular ROI of the tooth 106. Therefore, when the X-ray source 110 is activated, the X-ray beam indicated by 108 as a whole can be generated and projected onto the X-ray detector 120 through the ROI of the teeth 106. Since the distance D is a fixed and known quantity, the exact position of the focal point produced by the X-ray source array pixels with respect to the X-ray detector 120 is known. In this way, the reconstruction of the 2D projected image into a 3D image can be improved.

Referring to FIG. 2B, an alternative using the X-ray detector holder 150 is shown. In particular, the device shown by 200 overall can be utilized to connect the X-ray source (eg 110) to the X-ray detector (eg 120) at known distances from each other. In some embodiments, the device 200 can include a receptacle 210, which is mountable to an X-ray source and can be coupled to a coupling arm 220 that can be mounted on an X-ray detector. When the device 200 is used in an intraoral tomosynthesis system (eg 100), the receptacle 210 may be attachable to an X-ray source (eg 110) and may be magnetically coupled to the coupling arm 220, the coupling arm. May be attachable to an intraoral X-ray detector (eg, 120) placed in the patient's mouth.

In some embodiments, the receptacle 210 may be any suitable material, eg, any metal or metallic material (eg, aluminum (Al), steel, iron (Fe), alloys thereof, etc.), any non-metallic material (eg, any non-metallic material). For example plastics, polymers, etc.), non-magnetic materials, magnetic materials, and / or any combination thereof. The receptacle 210 may include a metal receptacle configured to be attached to an X-ray source. The receptacle 210 may include an overall hollow interior as shown by 212 to allow collimating X-ray radiation from the X-ray source array. For attachment to the connecting arm 220, the receptacle 210 may include a tilted channel, generally indicated by 214, arranged along the outer side surface. The channel 214 can be disposed along the entire length of the receptacle 210 and can be correspondingly sized and molded to accommodate the raised inner surface 228 of the longitudinal portion 222 of the connecting arm 220.

In some embodiments, the connecting arm 220 is made of any suitable material, such as any metal or metal material (eg, aluminum (Al), steel, iron (Fe), alloys thereof, etc.), any non-metal material. It can include non-magnetic materials (eg plastics, polymers, etc.), magnetic materials, and / or any combination thereof. For example, the connecting arm 220 can include a magnetic longitudinal portion 222, an elbow 224, and an X-ray detector holder 226. The first end of the elbow 224 is disposed towards one end of the longitudinal portion 222 and can extend perpendicularly from the longitudinal portion, thereby forming a right angle to the longitudinal portion. The X-ray detector holder 226 can be disposed at the second end of the elbow 224 and can be configured to hold the X-ray detector (eg, 120) in a fixed manner. When the X-ray detector is an intraoral X-ray detector, the X-ray detector holder 226 can be configured to fix and dispose the intraoral X-ray detector in the patient's mouth.

The longitudinal portion 222 of the connecting arm 220 can include a raised inner surface 228 that can be sized and molded into the channel 214 of the receptacle 210 so as to be removable. In some embodiments, the connecting arm 220 can be configured to be moved so as to be attached to and detached from the receptacle 210 via a magnetic attachment. For example, the magnetic attachment can include the metal contacts generally shown by 216, along the length of one or both of the raised inner surfaces 228 of the channel 214 and the longitudinal portion 222. The metal contacts 216 can be configured to provide immediate feedback on the accuracy of alignment and coupling between the channel 214 and the inner surface 228. In addition, such contacts 216 can allow the rapid release function of the device 220, which can be useful, for example, when the patient suddenly moves.

Next, referring to FIGS. 3A-3B, the first exemplary implementation of the geometry calibrator overall shown at 300 for use in an intraoral tomosynthesis system equipped with an X-ray source 310 and an X-ray detector 320. The morphology is shown. The geometry calibrator 300 is, for example, a plate or screen 330, at least one light source 340, a camera 350, at least one gyroscope 360, or any configured to calculate and / or detect orientation and rotation. It can be equipped with other devices.

In some embodiments, the position of the X-ray detector 320 with respect to the X-ray source 310 may be fixed, even in embodiments where the X-ray source 310 and the X-ray detector 320 are not physically connected to each other. For example, in FIGS. 3A and 3B, the X-ray source 310 and the X-ray detector 320 are not physically separated by a mechanical link mechanism such as the X-ray detector holder 150 of FIGS. 1-2B. It shows that the fixed position of the X-ray source with respect to the X-ray detector can be maintained in another form. Instead, the X-ray source 310 and the X-ray detector 320 may be physically separated from each other so that the relative position of the X-ray detector 320 with respect to the X-ray source 310 can be dynamically determined by geometry calibration techniques. , This is explained in more detail below.

In some embodiments, the astrophysical source 310 can include an astrophysical source array 312 as shown by overall 312, including individually programmable x-ray pixels 314. As shown in the exemplary embodiment of FIG. 3A, the 5 to 20 pixels 314 may be distributed as a substantially linear array and are configured to project X-rays onto the X-ray detector 320. Often, it produces a projected image of the ROI of the object (eg, the patient's teeth). However, since the X-ray source 310 and the X-ray detector 320 are not physically connected to each other, a geometry calibrator 300 is used to geometrically calibrate the position of the X-ray detector 320 with respect to the X-ray source 310. can do.

In some embodiments, the at least one light source 340 projects the light beam generally shown by 342 onto the plate 330 to determine the translational position of the plate 330 with respect to the X-ray source 310, and the overall 344. The light spot indicated by can be generated. In some embodiments, the X-ray detector 320 can be physically coupled to the plate 330. For example, a crossbar 322 can be used to secure the X-ray detector 320 to the plate 330. The crossbar 322 can have a length between, for example, about 2 cm and 20 cm. In some embodiments, the length of the crossbar 322 can be adjusted. The plate 330 can include, for example, any combination of paper, plastic, metal or such materials having approximate dimensions from about 5 cm and 20 cm. In some embodiments, the crossbar 322 can secure the plate 330 to the X-ray detector 320 such that the plate 330 is in a plane parallel to the plane in which the X-ray detector 320 is located. In another aspect, the plate 330 may be tilted with respect to the X-ray detector 320.

In some embodiments, when the detector 320 is configured as an intraoral X-ray detector, the plate 330 can protrude from the patient's mouth. Thus, since the plate 330 can be connected to the X-ray detector 320 at a known fixed distance, the X-ray detector with respect to the X-ray source 310 can be determined by determining the angle and translational position of the plate 330 with respect to the X-ray source 310. The position of 320 can be determined.

In some embodiments, at least one light source 340 can be projected onto the plate 330. For example, at least one light source 340 can include a low power laser or other light configured to project onto the plate 330, eg a 5 mW laser pointer with a wavelength of 650 nm. The at least one light source 340 may be mounted on or otherwise mounted on the X-ray source 310 and / or the collimator. As shown in FIGS. 3A-3B, the illustrated embodiment has four light sources 340, each located in a separate corner of the X-ray source 310. Each of the four light sources 340 is tilted towards the plate 330 to project a light beam 342 onto the plate 330, thereby producing four separate light spots 344 (see, eg, 344A-D in FIG. 4). can do. Depending on the angle of incidence at which each of the four light sources 340 is directed at the plate 330, the light spot 344 can form a rectangle, square, triangle, or any other shape, with each projected light beam. 342 produces a light spot 344 that forms the corner vertices of such a projected shape. In some embodiments, the angle of incidence at which each light source 340 is mounted on the X-ray source 310 may be known and can be used to determine the translational position of the plate 330 with respect to the X-ray source 310. In particular, as a result of arranging at least one light source 340 in this way, the shape formed by the light spots 344 produced from the projected light beam 342 on the plate 330 becomes as the plate 330 moves away from the X-ray source 310. It becomes smaller and becomes larger as the plate 330 approaches the X-ray source 310.

In some embodiments, the camera 350 can record the position of the projected light spot 344 on the plate 330 to determine the translational position of the plate 330 with respect to the X-ray source 310. In some embodiments, the camera 350 can also be configured to provide motion tracking and correction during the imaging procedure in the event of unintended movement of the object or system. The camera 350 can include, for example, an X-ray source 310 or a high resolution high speed digital camera that can be mounted in a known position on a collimator (not shown). As shown in FIGS. 3A-3B, the camera 350 may be mounted centrally on the upper surface of the X-ray source 310 and adjacent to the front edge of the X-ray source 310. In some embodiments, the camera 350 can transmit the captured photographic image to a computing platform (see, eg, 804 in FIG. 8). For example, the camera 350 sends a photographic image that captures the location of the light spot 344 on the plate 330 to the computing platform to determine the translational position of the plate 330 with respect to the X-ray source 310, thereby with respect to the X-ray source 310. The position of the X-ray detector 320 can be determined.

In some embodiments, at least one gyroscope 360 is included to determine the angular position of the plate 330 with respect to the X-ray source 310. For example, at least one gyroscope 360 may be described, for example, by Parallax Inc. Can include the Parallax Gyroscope Module 3-axis L3G4200D commercially available from manufacturers including. Therefore, determining the angular position of the plate 330 with respect to the X-ray source 310 can be achieved with one of several techniques. For example, the first technique is to mount the first gyroscope 360 on the X-ray source 310 and the second gyroscope (not shown) on the plate 330 and data from each gyroscope on the computing platform. It can include comparing points. In another example, the second technique is to reset the plate 330 by arranging the plate 330 in the same plane as the X-ray source array 310, and the first gyroscope 360 mounted on the X-ray source 310. It can include resetting the data and measuring deviations from the initial X-ray source plane during the imaging process.

Next, referring to FIG. 4, an exemplary image capture from a camera (eg, 350) is captured as a result of a light beam 342 projected onto a plate 330 and producing light spots generally indicated by 344A-D. The image is shown. In this example, four separate light spots 344A-D are produced from the light beam 342 generated from the four separate light sources 340 arranged in the same manner as described above with reference to FIGS. 3A-3B. Each light point 344A-D forms one corner of the rectangular shape or the apex of the rectangular shape. A coordinate system can be defined to establish x, y, and z directions to determine the translational position of the X-ray detector 320 with respect to the X-ray source 310. In some embodiments, the distance between each light spot can determine the z-offset of the plate 330 with respect to the X-ray source 310. For example, the horizontal or _x -distance measured between the first light point 344A and the second light point 344B, or between the second light point 344B and the third light point 344C. The vertical or _y -distance by can determine the z-offset of the plate 330, and thus the X-ray detector 320, with respect to the X-ray source 310. The reason is that the distance between the light spots 344A to D is uniquely determined by any diffraction grating attached to at least one light source 340, the wavelength of at least one light source 340, and the z offset specification. be. In another aspect, the ratio of the distance from the light spot to the edge of the plate 330 to the distance between the opposing edges of the plate 330 can determine the x-offset or y-offset of the plate 330 with respect to the X-ray source 310. For example, the ratio of the horizontal or x-distance a x from the light spot 344D to the edge of the plate 330 to the horizontal or _{x-distance c x between} the two opposing edges of the plate 330 (eg, a _x / c _x ) is X. The x-offset of the plate 330 and thus the X-ray detector 320 with respect to the source 310 can be determined. In another exemplary example, the ratio of the vertical or y distance a _y from the light spot 344D to the edge of the plate 330 to the vertical or y distance cy between the two opposing edges of the plate 330 (eg, a _y / c ₎ . _y ) can determine the y offset of the plate 330, and thus the X-ray detector 320, with respect to the X-ray source 310.

Referring now to FIGS. 5A-5D, a second of the exemplary geometry calibrator 500 shown overall 500 for use in an intraoral tomosynthesis system including an X-ray source 510 and an X-ray detector 520. An embodiment is shown. Here, exemplary continuous acquisition of tomographic images using the geometry calibrator 500 is shown. 5A shows the initial setup of the geometry calibrator 500, where FIGS. 5B-5D are two different positions (eg, a first position shown in FIGS. 5B-5C and a second position shown in FIG. 5D). Shows sequential activation of different cathodes in an array of X-ray sources in. In particular, the device 500 can include, for example, a plate or screen 530, a light source 540, and a camera 550.

Referring to FIG. 5A, the apparatus 500 can be configured in the initial configuration before acquiring the 2D projected image. Although the position of the X-ray detector 520 with respect to the X-ray source 510 may be fixed, in this embodiment the X-ray source 510 and the X-ray detector 520 are shown as not physically connected to each other. Therefore, the mechanical link mechanism does not connect between the X-ray source 510 and the X-ray detector 520 and does not maintain a fixed separation between them. Instead, the X-ray source 510 and the X-ray detector 520 are physically separated from each other so that the relative position of the X-ray detector 520 with respect to the X-ray source 510 can be dynamically determined by geometry calibration techniques. , This is explained in more detail below.

In some embodiments, the astrophysical source 510 may comprise an astrophysical source array as shown by overall 512, including individually programmable x-ray pixels 516. As shown in FIGS. 5A-5D, nine pixels 516 may be distributed as a linear array, and these pixels are the X-ray beam shown in 514 as a whole (see, for example, FIGS. 5B-5D). Can be configured to project onto the X-ray detector 520 to generate a projected image of the ROI of the object 502 (eg, the patient's teeth). However, since the X-ray source 510 and the X-ray detector 520 are not physically connected to each other, a geometry calibrator 500 is used to geometrically calibrate the position of the X-ray detector 520 with respect to the X-ray source 510. can do.

In some embodiments, the X-ray detector 520 may be physically coupled to the plate 530. For example, a crossbar 522 can be used to secure the X-ray detector 520 to the plate 530. The crossbar 522 can have a length between, for example, about 2 cm and 20 cm. In some embodiments, the crossbar 522 is adjustable in length. Plate 530 can include, for example, paper, plastic, metal, or any combination thereof. In some embodiments, the crossbar 522 can secure the plate 530 to the X-ray detector 520 such that the plate 530 is in a plane parallel to the plane in which the X-ray detector 520 is located. In another aspect, the plate 530 may be tilted with respect to the X-ray detector 520.

In some embodiments, when the detector 520 is configured as an intraoral X-ray detector, the plate 530 can protrude from the patient's mouth. Therefore, the plate 530 can be connected to the X-ray detector 520 at a known fixed distance (eg, using a crossbar 522), thus determining the angle and translational position of the plate 530 with respect to the X-ray source 510. Therefore, the position of the X-ray detector 520 with respect to the X-ray source 510 can be determined. The plate 530 can be made from any combination of paper, plastic, metal, or such materials having approximate dimensions between, for example, 5 cm and 20 cm.

The light source 540 is configured to project the light beam generally indicated by 542 onto the plate 530 and generate the light spots generally indicated by 544 to determine the translational position of the plate 530 with respect to the X-ray source 510. Can be done. In some embodiments, only one light source 540 may be required as compared to the first embodiment of the geometry calibrator 300. The light source 540 may be mounted on or otherwise mounted on an X-ray source 510 and / or a collimator (not shown). In some embodiments, the light source 540 is integral with the camera 550 and both can be configured to be attached to the X-ray source 510. As shown in FIGS. 5A-5D, the light source 540 may be mounted on the camera 550 and mounted adjacent to its front edge in the center of the X-ray source 510. In particular, the light source 540 can include a low power laser or other light configured to project onto the plate 530, eg, a 5 mW laser pointer with a wavelength of 650 nm.

In some embodiments, at least one diffraction grating (not shown) with known diffraction line spacing at known relative positions can be attached to the X-ray source 510. For example, a one-dimensional (1D) diffraction grating can be used. In another example, two gratings can be used in which the first grating is a 1D diffraction grating and the second grating is a 2D diffraction grating. In some embodiments, the grids can each include diffraction line spacings that may be similar or different from each other. The diffraction line spacing can include the distance between each diffraction line in the grid. In other embodiments, the grids can contain the same optical dimensions and can be oriented in different directions with respect to each other. If the geometry calibrator 500 comprises at least one grating, the light beam 540 can be fitted such that the light beam 542 passes through the grating at a known location with respect to the X-ray source 510 and has passed through the grating. As a result, the light source 540 is separated vertically (y) and horizontally (x) according to the following separation formula y = mλD / d, where m = 0, 1, 2, and 3 indicate the order of the diffraction points, and λ is It is the wavelength of the light source 540, D is the distance from the diffraction source to the plate 530, and d is the diffraction grating slit separation.

In some embodiments, the camera 550 can record the position of the light spot 544 projected onto the plate 530 to determine the translational position of the plate 530 with respect to the X-ray source 510. In some embodiments, the camera 550 can also be configured to provide motion tracking and correction during the imaging procedure in the event of unintended movement of the object 502 or system (eg, system 100). The camera 550 can include, for example, a high resolution high speed digital camera that can be mounted in a known position on an X-ray source 510 or a collimator (not shown). As discussed above, the camera 550 may also be fitted with a light source 540 in the center of the X-ray source 510, adjacent to the front edge of the X-ray source 510. In some embodiments, the camera 550 can transmit the captured photographic image to a computing platform (see, eg, 804 in FIG. 8). For example, the camera 550 can send a photographic image that captures the position of the light spot 544 on the plate 530 to the computing platform to determine the translational position of the plate 530 with respect to the astrophysical source 510, thereby X-rays. The position of the X-ray detector 520 with respect to the source 510 is determined.

Thus, the light source 540 and camera 550 are tilted towards the plate 530 to project the light beam 542 onto the plate 530 through at least one grating, thereby causing light spots 544 (eg, illustration) at different locations on the screen 530. 6A-see 544A-C in FIG. 6C), thus providing a light pattern on the screen 530. In particular, different light patterns can be obtained as a result of different locations of the light source 540 and / or the screen 530, each of which is captured by the camera 550 and captures the geometry of the screen 530 and the attached X-ray detector 520. It can be used to calibrate for each pixel in the X-ray source 510.

When the device 500 is configured and ready to generate a 2D projected image, the camera 550 receives an initial light produced by a light source 540 (eg, a laser) when the X-ray detector 520 and screen 530 are in the first position. The pattern can be configured to be captured and sent to a computing platform (eg, 804) for processing and geometry calibration. For example, the camera 550 may be configured to capture a light spot 544 that forms an initial light pattern on the screen 530 when the X-ray detector 520 and the screen 530 are in the initial or first position. can. This processing of the captured image can be used as a reference for geometry calibration.

Next, with reference to FIGS. 5B-5D, acquisition of a 2D projected image is shown, where each pixel 516 in the X-ray source array 512 of the X-ray source 510 has an X-ray detector 520 and a screen 530. It is sequentially activated when it is in the first position and then in the second position. Although FIGS. 5B-5D show sequential activation of only three pixels 516 and only two different positions, those skilled in the art will appreciate that these figures are merely exemplary and non-limiting. Will recognize. For example, each pixel 516 in the X-ray source 510 can be activated and the detector 520 is configured to record the resulting image. As shown in FIGS. 5A-5D, if there are 9 pixels 516, all of the 9 pixels 516 can be individually activated and the X-ray detector 520 will be relative to the activated pixels 516. It can be configured to record each image for each position of the X-ray detector 520. In some embodiments, the X-ray detector 520 only needs to be in one position, in which case it is only necessary to activate the nine pixels 516 once, and activation of each pixel 516 is performed individually. To. However, if the X-ray detector 520 is moved to multiple positions, each of the nine pixels 516 will be individually reactivated as the X-ray detector 520 is moved to each of the subsequent positions. Will be done.

In FIG. 5B, the second pixel 516A in the X-ray source 510 is shown in an activated state to generate an X-ray beam 514 projected onto the detector 520, where the detector is screen 530. And record the projected image while the X-ray detector 520 is in the first position. In particular, the first of the pixels 516 in the X-ray source 510 may be activated before the second pixel 516A in the X-ray source 510 is activated, the X-ray detector 520 may activate it. The image generated by may be recorded. Similarly, in FIG. 5C, the third pixel 516B in the X-ray source 510 is activated to generate an X-ray beam 514 projected onto the detector 520, where the detectors are the screen 530 and the X-ray detector. The projected image is recorded while the 520 is in the first position. Since the screen 530 remains in the first position during activation of the second pixel 516A and the third pixel 516B in the X-ray source array 512, the light pattern generated by the light spot 544 is for the purpose of geometry calibration. It remains the same.

However, in FIG. 5D, the screen 530 and the X-ray detector 520 are moved to a second position different from the first position (indicated by the dotted line). In the example shown in FIG. 5D, the screen 530 and the X-ray detector 520 are moved in the x direction to the left with respect to the X-ray source 510. The screen 530 and the X-ray detector 520 can move, but the X-ray source 510 remains in its initial position. In such a scenario, the light spot 544 projects onto the screen 530 at a different location than when the screen 530 was in the first position, so that when the light beam 542 is projected onto the screen 530, the light spot. The light pattern formed from 544 has a different geometry. This still applies to any trailing positions where the screen 530 and X-ray detector 520 are moved, and each trailing position is also different from the first position and each other's position.

Therefore, when the screen 530 and the X-ray detector 520 are moved to a second position or an arbitrary position other than the first position, the camera 550 has the X-ray detector 520 and the screen 530 other than the first position. A computing platform for capturing the second light pattern produced by the light source 540 and processing the captured second light pattern and calibrating the geometry when in any position in (eg, 804 in FIG. 8). Can be configured to send to. For example, the camera 550 may be configured to capture an image containing a light spot 544 forming a second light pattern on the screen 530 when the X-ray detector 520 and the screen 530 are in the second position. can. This processing of the captured image can be used as a reference for geometry calibration. In some embodiments, still referring to FIG. 5D, the fourth pixel 516C in the X-ray source array 512 can be activated to produce an X-ray beam 514 projected onto the detector 520. The detector records the image projected while the screen 530 and the X-ray detector 520 are in the second position. Activation of each contiguous pixel 516 in the X-ray source array 512 at the second position is also to generate another contiguous image while the X-ray detector 520 and screen 530 are in the second position. It can happen.

In some embodiments, 3D image reconstruction can be initiated after each pixel 516 in the X-ray source array 512 is activated and the projected image is recorded by the X-ray detector 520. For example, 3D image reconstruction can include tomosynthesis reconstruction. 3D image reconstruction is accomplished using computer programs and / or workstations (eg, 804 in FIG. 8) to analyze, calibrate, and reconstruct 3D tomographic images from recorded 2D projected images. It can be displayed and so on. Geometry calibration data (eg, photographic images) captured and recorded by camera 550 is utilized by computer programs and / or workstations to determine the relative position of each pixel 516 of the X-ray source array 512 with respect to the X-ray detector 520. Can be decided. This position data is used for tomosynthesis reconstruction of 3D images of teeth.

Next, referring to FIGS. 6A-6C, each of them shows an example of a captured image obtained as a result of a light beam 542 projected onto a plate 530 to generate a light spot 544. Each of FIGS. 6A-6C shows a different position and / or orientation of the screen 530 with respect to a light source (eg, 540). In particular, as a result of moving the screen 530 with respect to the light source, the light pattern produced by the light spots 544 on the screen 530 can change. Therefore, by comparing and analyzing the patterns of the light spots 544, the relative movement of the X-ray source 510 with respect to the detector 520 can be determined.

FIG. 6A shows a first schematic view of the first light pattern, generally shown at 544A, shown at 600A overall, produced in the first position and first orientation of the screen 530 with respect to the light source. In FIG. 6A, the light spots of the first light pattern 544A form a first light pattern, which is such that the screen 530 is at a "short z distance" with respect to the light source and on an X-ray source (eg 510). It is shown that it is arranged in a plane parallel to the plane including the light source mounted on the. Here, "short" is defined for FIG. 6B and "long z-distance", i.e., that the z-distance from the X-ray source is smaller than when the screen 530 is placed along the long z-distance. Therefore, when the screen 530 is placed closer to the light source in the z direction, the separated light spots of the first light pattern 544A become closer.

FIG. 6B is a second schematic, but still produced in the first orientation of the screen 530 with respect to the light source, shown at 544B overall, and at 600B overall for the second light pattern. The figure is shown. In FIG. 6B, the light spots of the second light pattern 544B form a second light pattern, which the screen 530 is mounted at a "long z distance" with respect to the light source and on an X-ray source. Indicates that they are arranged in a plane parallel to the plane containing the light source. Therefore, when the screen 530 is arranged farther from the light source in the z direction, the light spot of the second light pattern 544B becomes wider.

FIG. 6C is a third schematic view of the third light pattern, generally shown at 544C, produced at the third position and second orientation of the screen 530 with respect to the light source, shown at 600C overall. show. In FIG. 6C, the light spots of the third light pattern 544C form a second light pattern, which the screen 530 mounts at a z distance of about 10 cm to 40 cm with respect to the light source and on the X-ray source. Indicates that it is placed in a plane rotated with respect to the plane containing the light source. When the screen 530 is rotated with respect to the plane containing the light source, the relative distance between each light point of the third light pattern 544C may be different from the case where the screen 530 is oriented parallel to the plane containing the light source. In such cases, the rotation calculation can be used during calibration to determine the angular position of the X-ray detector (eg, 520) connected to the screen 530 with respect to the X-ray source. Therefore, as the screen 530 rotates more with respect to the plane containing the light source, the relative distance between each light point of the third light pattern 544C increases. On the contrary, if the screen 530 does not rotate much with respect to the plane including the light source, the relative distance between the light points of the third light pattern 544C becomes small.

Next, with reference to FIG. 7, a third embodiment of an exemplary embodiment of the geometry calibrator 700 for use in an intraoral tomosynthesis system (eg, system 100) is schematically shown. The geometry calibrator 700 can include, for example, a light source 710, a camera 720, a screen or plate 730, a first grid 740, and a second grid 750.

The light source 710 can include a visible light laser or any other light source attached to an X-ray source array (not shown in this embodiment). The light source 710 can provide light of any suitable known frequency and wavelength. In some embodiments, only one light source 710 may be required as compared to the first embodiment of the geometry calibrator 300. In some embodiments, the camera 720 is attached to the light source 710 and attached to an X-ray source array. For example, the camera 720 can be mounted above or below the light source 710, or at any suitable position relative to the light source 710, as will be appreciated by those skilled in the art.

In some embodiments, the light source 710 can be projected onto a screen or plate 730 through at least one optical grating. Two optical diffraction gratings 740 and 750 are included in the geometry calibrator 700. The screen or plate 730 can be attached to an X-ray detector (not shown in this embodiment) and placed in front of the ROI of the object to be imaged. For example, the screen 730 can be attached to an intraoral X-ray detector and placed outside the patient's mouth. The plate 730 can be attached to the X-ray detector at known relative positions using, for example, a crossbar (eg, 322, 522, respectively in FIGS. 3A-3B and 5A-5D). The plate 730 can include paper, plastic, metal or any combination of these materials, and the dimensions of the plate 730 are about 5 cm to 20 cm.

In some embodiments, the plate 730 can include a predetermined calibrated marker 732 that is centrally or otherwise placed. A predetermined calibrated marker 732 can include a square or other enclosing shape that encloses one area. The light source 710 can be configured to project the divided light beam, generally shown by 752, onto the plate 730, in particular within the shape formed by the predetermined calibrated marker 732. A predetermined calibrated marker 732 can be used as a reference point for light spots M0, M1, M2, etc. to determine the position of the X-ray detector with the plate 730 relative to the X-ray source. , Will be discussed in more detail below. In some embodiments, the plate 730 comprises a calibration circle 734 defined within a predetermined calibrated marker 732. The position of the calibration circle 734 may be pre-determined by the operator as corresponding to the desired position of the light source 710. Therefore, the operator can adjust the position of the light source 710 so that the light beam 702 generated by the light source 710 produces an initial light point M0 within the calibration circle 734.

In some embodiments, at least one grating can be attached to the X-ray source at a known location. As shown in FIG. 7, the two diffraction gratings 740 and 750 are arranged in front of the light source 710, whereby the light beam emitted from the light source 710 has a grating 740 and 750 capable of dividing the light beam. Can be projected through. The divided light beam can then be projected onto the plate 730 in the form of a plurality of light spots M1 and M2. In particular, the initial light spot M0 from the light beam is also projected onto the plate 730.

In some embodiments, the gratings 740 and 750 can be 1D or 2D optical diffraction gratings with known diffraction line spacing between them. According to the exemplary embodiment of FIG. 7, the first diffraction grating 740 is a 1D diffraction grating, and the second diffraction grating 750 is also a 1D diffraction grating. In some embodiments, the gratings 740 and 750 can each include diffraction line spacings that may be similar or different from each other. The diffraction line spacing can include the distance between each diffraction line in the grid. For example, the first diffraction grating 740 and / or the second diffraction grating 750 may be configured with a diffraction line spacing which may include diffraction lines separated by, for example, about 0.001 mm to 0.1 mm. can. In another aspect, the grids 740 and 750 can contain the same optical dimensions and can be oriented in different directions with respect to each other. In FIG. 7, for example, the first diffraction grating 740 and the second diffraction grating 750 are rotationally oriented with respect to each other. According to this exemplary embodiment of the geometry calibrator 700, the first grid 740 is rotated 90 degrees with respect to the orientation of the second grid 750.

The grids 740 and 750 can be configured to divide the initial light beam 702 emitted by the light source 710 to generate a plurality of light spots M1 and M2 on the plate 730. The initial light beam 702 can be a light beam that includes wavelengths in the visible range (eg, about 390 nm to 700 nm). The initial light spot M0 can be generated by the light beam 702 and can be used as a reference for arranging the light source 710 and thus the X-ray source within the calibration circle 734.

The light beam 702 can also be configured to pass through one or more diffraction gratings. Since the geometry calibrator 700 has at least one diffraction grating (eg, first and second diffraction gratings 740,750), the light source 710 has a diffraction grating 740 and a location where the light beam 702 is known to the X-ray source. It can be mounted to pass through the 750, and as a result of passing through the gratings 740 and 750, the light source 710 is separated in the vertical (y) and horizontal (x) directions according to the following separation equation y = mλD / d. Medium m = 0, 1, 2, 3 indicates the order of the diffraction point, λ is the wavelength of the light source 710, D is the distance of the plate 730 from the diffraction source, and d is the diffraction grating slit separation. As shown in FIG. 7, for example, the light beam 702 passes through a first diffraction grating 740 and a second diffraction grating 750, and each grating is rotated 90 degrees with respect to the other. The first diffraction grating 740 is configured with a first diffraction grating spacing including, for example, horizontal lines spaced from about 0.001 mm to 0.1 mm, and the second diffraction grating 750 is, for example, from about 0.001 mm. It is configured with a second diffraction line spacing including vertical lines separated by 0.1 mm. It will be appreciated that other diffraction line spacings, both vertical and horizontal, are within the skill of one of ordinary skill in the art. Therefore, the beam 702 is horizontally divided into a plurality of horizontal beams 742 by the first diffraction grating 740, and the central beam passes through the second diffraction grating 750, and as a result, this center of the horizontal beam 742. The beam is split into separate vertical beams 752. In some embodiments, the divided horizontal and vertical beams 742 and 752 can be projected onto a plate 730 within a region defined by a predetermined calibrated marker 732. According to an exemplary embodiment of FIG. 7, eight separate beams, four of which are horizontal beams 742 and four of which are vertical beams 752, are projected onto the plate 730 to provide eight separate light spots M1 and M2. Form the including 2D light pattern 736. In this exemplary embodiment, four light spots M1 and four light spots M2 are formed, and the initial light spot M0 is located within the center of the light pattern 736 formed from the light spots M1 and M2. However, multiple diffraction point orders such as M0, M1, M2 can be used to determine the position of the light source 710 with respect to the plate 730 and thus the position of the X-ray source with respect to the X-ray detector.

In some embodiments, the camera 720 captures at least one projected image of the light spots M1, M2 and the initial light spot M0 within a predetermined calibration marker 732 and sends the at least one captured image to the computing platform. (See, for example, 804 in FIG. 8). For example, the camera 720 determines the translational position of the plate 730 with respect to the X-ray source, thereby the initial light spot M0 in the calibration marker 732 on the plate 730 to determine the position of the X-ray detector with respect to the X-ray source. And an image that captures the positions of the light spots M1 and M2 can be transmitted to the computing platform. Thus, for each intensity peak, when the beam 702 hits the first grid 740 using a light pattern 736 with an initial light spot M0, light spots M1, M2, a predetermined calibration marker 732, and a diffraction angle θm. The position of the light and the distance between the respective light spots M1 and M2 on the plate 730 can be determined in the computing platform. For example, the geometry calibration module calculates the position when the beam 702 hits the first grid 740, the distance between each of the light spots M1 and M2 on the plate 730, and the three angles of axial rotation of the plate 730. be able to. In particular, all six degrees of freedom of the plate 730 are determined from the light pattern 736 formed by the light spots M1 and M2 with respect to the first beam split point (eg, where the beam 702 hits the first grid 740). Can be done. As a result, the complete geometry of the imaging system can be determined based on the relative position of the X-ray detector with respect to the plate 730 and the relative position of the X-ray source with respect to the light source 710.

Therefore, regardless of the technique used for the purpose of geometry calibration, the angle and / or translational position of the X-ray detector with respect to the X-ray source can be determined, thereby the tomosynthesis image from the acquired X-ray projection image. Can help to reconstruct exactly. Thus, the determined position of the X-ray source during image acquisition (eg, angular position and / or translational position) can make it possible to generate a tomosynthesis reconstructed image of the imaged object.

Next, with reference to FIG. 8, a schematic system diagram, generally shown by 800, of an exemplary embodiment of a fixed intraoral tomosynthesis system 802 interfaced with an exemplary computing platform 804 is shown. In particular, when configured as described herein, an exemplary computing platform 804 acquires 2D projected images from multiple viewpoints, which are then imaged from an X-ray source or patient movement. Processing without accompaniment provides a dedicated computing platform that can improve the technical field of fixed intraoral tomosynthesis imaging for 3D dental imaging.

In some embodiments, the exemplary tomosynthesis system 802 comprises a tomosynthesis system as described above in FIG. 1 (eg, 100), FIG. 9 and / or FIG. In some embodiments, the tomosynthesis system 802 can include a geometry calibrator 810 such as that described above (eg, 300, 500, 700). The tomosynthesis system 802 can be configured to interface with a computing platform 804 for calibrating the geometry of the system 802 by processing photographic images. For example, the tomosynthesis system 802 may include one or more projected images from the oral detector to the computing platform 804 via an interface such as a data transmission line connecting the oral detector to the computing platform, wireless transmission, and the like. Can be configured to send. The computing platform 804 may also be configured for tomosynthesis reconstruction of 2D projected images.

The computing platform 804 can be configured to perform one or more aspects related to calibrating the geometry of the system 802. In some embodiments, the computing platform 804 may be software running on one or more stand-alone entities, devices, or processors. In some embodiments, the computing platform 804 may be a single node or may be distributed across multiple computing platforms or nodes. The computing platform 804 may also be suitable for use for purposes other than geometry calibration.

In some embodiments, the computing platform 804 is configured to perform one or more aspects associated with calibrating the geometry of the tomosynthesis system 802, as well as aspects other than geometry calibration such as tomosynthesis reconstruction. A geometry calibration module 806 can be included. In some embodiments, the computing platform 804 may also include a separate tomosynthesis reconstruction module (not shown) configured to reconstruct the acquired 2DX ray projected image. In particular, the geometry calibration module 806 can be configured to perform tomosynthesis reconstruction and geometry calibration. The geometry calibration module 806 may be any suitable entity (eg, software running on a processor) for performing one or more aspects related to geometry calibration of the tomosynthesis system 802. The geometry calibration module 806 can include the ability to receive at least one photographic image from a camera (eg, 350, 550, 720) during one or more image acquisition sessions. For example, the interface 808 associated with the geometry calibration module 806 and / or the computing platform 804 is a screen from the geometry calibrator 810 for each adjustment in the position of the X-ray detector with respect to the ROI of the object to which the screen, plate, etc. are mounted. , Light patterns on plates, etc., can receive photographic images at various positions such as light spots. In this example, the user of the geometry calibration module (eg, a device or computing platform available by the user or operator) receives light on a screen, plate, etc. for each adjustment in the position of the X-ray detector with respect to the ROI of the object. At least one photographic image, such as a pattern, light spot, etc., is captured and this image can be later received by the geometry calibration module 806.

A tomosynthesis reconstruction module, separate from or integrated with the geometry calibration module, can be configured to acquire and / or process a 2DX ray projected image of the object. For example, the tomosynthesis reconstruction module is a 2DX ray acquired of an object by various algorithms including, for example, filtered backprojection and iterative reconstruction (eg, iterative truncation artifact reduction). It can be configured to reconstruct the projected image.

The computing platform 804 and / or the geometry calibration module 806 may include the ability to store one or more photographic images for future use. In some embodiments, the compute platform 804 and / or the geometry calibration module 806 may include the ability to instantiate or initialize an image and / or provide the image to another computing platform or device. For example, the compute platform 804 and / or the geometry calibration module 806 receives one or more photographic images, calibrates the geometry of the system 802 based on those images, and / or calibrates those images via interface 808. Can be provided to other nodes for geometry calibration of the tomosynthesis system 802.

In some embodiments, the computing platform 804 and / or the geometry calibration module 806 includes or has access to a data storage device 812 containing data and / or photographic images associated with the geometry calibration of the tomosynthesis system 802. Can be done. For example, the computing platform 804 and / or the geometry calibration module 806 can access a data storage device 812 that houses previous photographic images, mapped coordinate systems, image data, profiles, settings, or configurations. Exemplary embodiments of the data storage device 812 can include non-transitory computer-readable media such as flash memory, random access memory, non-volatile media, and / or other storage devices. In some embodiments, the data storage device 812 may be external to and / or integrated with the computing platform 804 and / or the geometry calibration module 806.

In some embodiments, the computing platform 804 and / or the geometry calibration module 806 can include one or more communication interfaces for interacting with users and / or nodes. For example, the computing platform 804 and / or the geometry calibration module 806 can provide a communication interface for communicating with the user of the computing platform 804 and / or the geometry calibration module 806. In some embodiments, the user of the computing platform 804 and / or the geometry calibration module 806 may be an automated system, or may be controlled or controllable by a human user. Users of the Compute Platform 804 and / or the Geometry Calibration Module 806 use the camera of the device 810 to capture one or more photographic images and combine these images with the Compute Platform 804 and / or the Geometry Calibration Module 806. Can be sent to. The computing platform 804 is configured to display at least a portion of the reconstructed 3D tomosynthesis image and / or at least a portion of one or more 2D projected images, according to the exemplary embodiment of FIG. Shown as being electrically connected to one or more monitors 814. The one or more monitors 814 may be of any suitable type (eg, CRT, LCD, OLED, holographic, projection, etc.) and may be arranged in any suitable configuration and number.

In some embodiments, the computing platform 804 may include the ability to configure the tomosynthesis system 802 described herein for acquiring a 2DX-ray projected image of the ROI of an object. For example, the computing platform 804 can control the acquisition of 2DX-projected images using the tomosynthesis system 802 by activating the X-ray source and initiating the generation of the X-ray beam. In another aspect, the computing platform 802 may include the ability to change conditions within the tomosynthesis system 802, including, for example, moving a translational stage, moving an X-ray detector relative to an object, and the like. .. In some embodiments, the computing platform 804 is capable of generating content (eg, a 3D tomosynthesis image reconstructed using a previously acquired 2DX ray projection image) and / or a memory associated with an imaging session. It can include the ability to retrieve the content that has been created.

According to another embodiment of the fixed intraoral tomosynthesis system shown overall at 900, the tomosynthesis system 900 shown in FIG. 9 has an X-ray source 930 and an intraoral X-ray detector overall shown at 912. An X-ray detector holder 910, a joint arm 950 with a degree of freedom device 940 at one end and a control unit 960 at the other end, and one end connected to the X-ray source 930. Another end includes an X-ray collimator 920 that is magnetically coupled to the X-ray detector holder 910. It is believed that the X-ray collimator 920 can be coupled to the X-ray detector holder 910 by any suitable fastener.

In some embodiments, the tomosynthesis system 900 may be fitted to be immobile. For example, the tomosynthesis system 900 can be mounted on a ceiling, a wall, or the like. In another aspect, the tomosynthesis system 900 may be mobile. For example, the tomosynthesis system 900 can include wheels and may be placed on a moving cart, hand truck, stand, or the like. Further, the control unit 960 can include a power supply, a control electronic device, a cable wiring, and the like, which are at least partially housed in the control unit 960. In some embodiments, the power supply (not shown) may be provided inside the joint arm 950 rather than inside the control unit 960. In some embodiments, the power supply may include a rechargeable battery (not shown) capable of supplying power for imaging, thereby the electrical cord and / or wire for the power in use. Remove the need. The joint arm 950, according to some embodiments, is attached to the control unit 960 at one end and at the other end the X-ray source 930 and / or the detection component (eg, X-ray detector 912). Can be attached to. In some embodiments, the cabling is routed from the control unit 960 to the X-ray source 930 and / or the detection component (eg, X-ray detector 912) along the joint arm 950 to 3D these components. Can be used for dental imaging. In another aspect, the cabling may be inside the joint arm. In a further aspect, the cabling may be provided separately from the joint arm or in a manner different from that described above. A degree of freedom (DOF) device 940 is provided between the joint arm 950 and the X-ray source 930, with the X-ray source 930 and / or the X-ray detector 912 in three degrees of freedom around the object to be imaged. Can be oriented.

The joint arm 950 can include an extension arm 952, a first arm section 954, and a second arm section 956. According to the embodiment shown in FIG. 9, the extension arm 952 is provided via a pivot and / or another type of attachment that allows the extension arm 952 to move substantially in a first plane. Attached to the control unit 960 at the end of 1. For example, the extension arm 952 of FIG. 9 may be pivotable in the first horizontal plane. The second end of the extension arm of this embodiment is via a pivot and / or another type of fixture that allows the first arm section 954 to pivot substantially in the second plane. And attached to the first end of the first arm section 954. For example, the first arm section 954 of FIG. 9 may be pivotable in a second vertical plane substantially perpendicular to the first horizontal plane. However, the pivot of the first arm section 954 in the second plane can be limited to about 180 degrees due to the interference of the extension arm 952. Thus, the second end of the first arm section 954 is a pivot and allows the second arm section 956 to pivot in the second plane in the direction opposite to the first arm section 954. / Or attached to the first end of the second arm section 956 via another type of fixture. For example, the second arm section 956 in FIG. 9 may be pivotal in the second vertical plane in a direction opposite to the direction of the first arm section 954. The second end of the second arm section 956 is attached to another suitable type of fixture that allows the DOF device 940 and / or the DOF device 940 to rotate around an axis. In this way, the tomosynthesis system 900 is adjustable in either x, y, and / or z around the object to be imaged. Thus, the tomosynthesis system 900 can be freely moved and rotated for optimal placement. As a result, the tomosynthesis system 900 can obtain multiple projections of the ROI of an object (eg, a patient's tooth) without moving any of the X-ray source 930, X-ray detector 912, or ROI. , Substantially fixed. This is due, at least in part, to the DOF device 940 or the joint arm 950 whose structure is attached to one end of the joint arm 950.

The X-ray source 930 and the X-ray detector 912 of FIG. 9 can be configured in the same manner as described above with reference to FIG. In some embodiments, the astrophysical source 930 has focal points that are spatially distributed in a linear or otherwise manner. In some embodiments, the X-ray tube current of each pixel in the X-ray source array is configured to be set to the same X-ray tube current using the control unit 960, and the extraction voltage corresponds to each. It is configured to be applied to the extraction gate of the pixel, and the X-ray irradiation level for each of the one or more X-ray projection images is set by changing the irradiation time. In some embodiments, the system described herein may be operated in a constant irradiation mode such that the X-ray irradiation level is adjusted by varying the X-ray tube current for each of the pixels. It is composed of.

In some embodiments, the x-ray detector 912 may be an intraoral x-ray detector configured to be inserted inside the patient's mouth. In another form, the X-ray detector 912 may be extraoral. Further, in some embodiments, the X-ray detector is synchronized with X-ray irradiation from a spatially distributed X-ray source array, one or more of the patients during one or more scans. It may be a digital detector that records images of X-rays, each of which is formed by X-ray radiation emitted from the corresponding focal point of a spatially distributed X-ray source array.

In some embodiments, the X-ray detector 912 shown in FIG. 9 is attached to the X-ray detector holder 910 for wing imaging applications. For example, FIG. 10 provides a more detailed perspective view of an exemplary embodiment of the X-ray detector holder 910. The X-ray detector holder 910 can include biocompatible plastics, but other materials that function for use in 3D dental imaging applications are also contemplated. The first end of the X-ray detector holder, generally indicated by 902, is shown to be configured to align with one end of the collimator, but any suitable detector is available. , The X-ray detector holder 910 may be snapped to the second end, generally indicated by 904, or fitted in another form. For example, the first end 902 of the X-ray detector holder 910 has a substantially rectangular profile and an aperture that matches the substantially rectangular profile of the collimator (see 920 in FIGS. 11A-11B). Has a center.

As used herein, a "collimator" includes an aiming cone (see, eg, 914 in FIGS. 11A-11B) and / or one or more X-ray limiting collimator plates. The link mechanism 908 can connect the first end 902 of the X-ray detector holder to the second end 904 of the X-ray detector holder. The linkage has a slight bend or curvature and opens the second end 904 of the X-ray detector holder into a substantially rectangular profile opening of the first end 902 of the X-ray detector holder 910. It can be placed so that it can be substantially placed in the center. The mechanism for attaching the detector to the X-ray detector holder may be integrally formed at the second end of the X-ray detector holder, or may be provided in another form.

In some embodiments, the first end 902 of the X-ray detector holder has a mechanism for keeping the X-ray detector holder 910 in a removable alignment with the collimator. According to this exemplary embodiment, a plurality of magnets 906 are provided around a substantially rectangular profile on the first end 902 of the X-ray detector holder 910. For example, 10 magnets 906 are embedded in the first end 902.

11A-11B show that the X-ray detector holder 910 of FIG. 9 is generally aligned with the second collimator plate 916 at one end of the collimator aiming cone 914 shown at 920. There is. The second collimator plate 916 of FIGS. 11A-11B has a substantially rectangular profile corresponding to a substantially rectangular profile on the first end 902 of the X-ray detector holder 910. A plurality of magnets 922 are provided on a substantially rectangular profile of the second collimator plate 916 and correspond positionally to magnets 906 provided on the first end 902 of the X-ray detector holder 910. .. However, the polarity of the magnets is reversed between these magnets on the second collimator plate 916 and the X-ray detector holder 910, whereby the X-ray detector holder 910 and the second collimator plate 916 are close enough. When brought to range, the magnets 906 and 922 on each component are attracted to each other and the components are brought to align with each other by magnetic force. Advantageously, the coupling between the X-ray detector holder 910 and the second collimator plate 916 on the aiming cone 914 helps ensure the placement of the two components relative to each other, which is permanent. It is not a proper installation. Therefore, the X-ray detector holder 910 and the second collimator plate 916 are brought out of alignment by applying a tensile or shearing force between the two structures and breaking the magnetic coupling between them. be able to.

FIG. 12 provides a further view of the aiming cone 914 of the collimator 920. An aiming cone 914 is placed between the first collimator plate 928 with X-ray limiting and / or attenuation characteristics and / or characteristics and the exit window 924 of the collimator 920, X-ray source 930, X-ray detector 912. , Or without any mechanical action of the collimator plates 916,928, limits or limit X-ray radiation to a substantially common area on the surface of the oral detector. In some embodiments, the first end of the aiming cone 914, generally indicated by 926, is proximal to or otherwise coupled to the X-ray source 930, while the aiming cone 914. The exit window 924 is located proximal to the X-ray detector holder 910 or is otherwise coupled to it. The first collimator plate 928 is located at the first end 926 of the aiming cone 914 and the second collimator plate 916 is located at the ejection window 924 of the aiming cone 914. Both the first and second collimator plates 928 and 916, in some embodiments, limit or otherwise attenuate the amount of X-ray radiation emitted from the collimator 920 in the direction of the X-ray detector holder 910. Can be configured to. According to one embodiment, the first collimator plate 928 can be configured to adjust one or more aspects of X-rays for each focal point, the second collimator plate 916. The X-ray field can be configured to further limit the shape and size of the intraoral X-ray detector to protect the patient. Both the first and second collimator plates 916 can contain materials with high levels of X-ray limiting and / or attenuation properties.

Still referring to FIG. 12, the second collimator plate 916 can have an opening center or a common opening with a diameter smaller than the diameter of the opening of the aiming cone 914 or the common opening. The common opening is shaped as a rectangle, but other shapes are also conceivable. The second collimator plate 916 is configured to be replaceable on the aiming cone 914 depending on the orientation and / or size of the X-ray detector. In this way, the second collimator plate 916 is rotatable, modifiable, and / or may be replaceable with a plate having a common opening of a different size and / or shape. The common opening can be configured to further limit the X-ray field to the shape and size of the intraoral X-ray and X-ray detector. For example, if the X-ray detector 912 is oriented laterally on the X-ray detector holder 910, the second collimator plate 916 will likewise aim to match the orientation of the X-ray detector 912. It can be oriented laterally on 914. In another example of the exemplary scenario, when the X-ray detector 912 is oriented in a vertical orientation on the X-ray detector holder 910, the second collimator plate 916 is similarly on the aiming cone 914. Can be oriented in a vertical orientation.

FIG. 13 further shows the first collimator plate 928. The first collimator plate 928 has one or more holes or openings 932 configured to align with one or more openings in the X-ray source, thereby, for example, the size of the X-ray field. Limits the beam intensity and / or the beam direction of the X-ray beam from the X-ray source 930. According to the exemplary embodiments of FIGS. 12 and 13, the seven openings 932 are linearly distributed over the length of the first collimator plate 928 and are also provided within the X-ray source 930. Corresponds to the opening (not shown). Brackets 934 for mounting the first collimator plate to the aiming cone 914 and / or the X-ray source 930 may be provided and integrated with the first collimator plate 928. According to this exemplary embodiment, the first collimator plate 928 is integrally formed of four for detachably mounting the plate on one or both of the aiming cone 914 and / or the X-ray source 930. It has a bracket 934.

Accordingly, FIG. 14 shows an exemplary embodiment of the collimator generally shown in 920, wherein the aiming cone 914 has a first collimator plate 928 at its first end and a second end thereof. Has a second collimator plate 916. Each of the seven focal points 948 present in this embodiment emits an X-ray beam 949 regulated by a first collimator plate 928. The X-ray beam 949 travels through a first collimator plate 928, an aiming cone 914, and a second collimator plate 916 to a sensor located on the X-ray detector 912, which sensor is an X-ray detector holder. It is substantially fixed and held by 910 during use. The second collimator plate 916 further limits the X-ray beam to the size and / or shape of the dimensions of the X-ray detector active region (eg, the region defined within the X-ray detector 912 from which data can be collected). Can be configured as follows. Thus, the collimator 920 can be configured such that X-ray irradiation from each focal point 948 is collimated to the same X-ray detector 912 within a particular percentage of the dimensions of the active detector region. For example, the collimator 920 can be configured to collimate X-ray radiation to about 1 percent (1 percent) of the dimensions of the active detector region. However, larger or smaller percentages are also contemplated without departing from the scope of the subject matter herein.

Then, with reference to FIG. 15, exemplary embodiments of the degrees of freedom (DOF) structure or apparatus shown overall at 940 are shown therein. The DOF device 940 is configured to be attached to the X-ray source 930 and the joint arm 950. In some embodiments, the DOF device 940 is for an object (eg, one or more teeth in the patient's mouth) to which the pivot, pin, screw, spring, and / or X-ray source 930 is imaged. It can be attached to the X-ray source 930 via any other mechanism that allows it to rotate with three independent degrees of freedom. For example, the first arm 942 may be attached to the sides and back of the X-ray source 930 via a pivotable pin 944 that allows the X-ray source 930 to rotate around the axes CL3 and CL4, respectively. Can be done. In this example, the second arm 946 is attached to the same side surface of the X-ray source 930 where the first arm 942 was attached, curved over the upper surface of the X-ray source 930, and of the joint arm 950. It can be attached to the end. The second arm 946 and the first arm 942 of the DOF device 940 are shown to be attached to the X-ray source 930 via the same pivotable pin 944, although these attachments are shown to be attached to the X-ray source. It can also be achieved by different pivotable pins 944 that allow the 930 to rotate around the axis CL2. The second arm 946 may be otherwise arranged on the other opposite side surface of the X-ray source 930. As will be appreciated by those skilled in the art, different structural configurations of the DOF device 940 that can allow rotation of the device around the three axes CL2, CL3, and CL4 are also available.

Next, with reference to FIG. 16, a perspective view of an exemplary embodiment of the linear X-ray source array shown overall at 935 is shown. The linear X-ray source array 935 can be configured with the same characteristics and functions as described above for the X-ray source array 110 of FIG. 1 (for example, the linear X-ray source array 935 of FIG. 16 can be configured. Can include one or more X-ray focal points). According to this embodiment, the linear X-ray source array 935 has a housing 936 for an X-ray tube (eg, CNT), one or more pixels, and one or more X-ray beams. And also has an X-ray emission window 938 configured to provide an outlet for unique filtration. In some embodiments, the X-ray emission window 938 is configured as a rectangular window to provide an exit for linearly distributed X-ray pixels. However, when the X-ray source array 935 is circular, the X-ray emission window 938 may have a corresponding circular shape. In all embodiments of the X-ray source array 935, the X-ray emission window 938 can have any suitable shape. As a result, it will be apparent to those skilled in the art that the X-ray emission window 938 of the X-ray source array 935 is configured to correspond to the size and / or shape of the X-ray pixel dispersion within it.

Therefore, the relative orientation of the X-ray source array with respect to the X-ray detector will affect the scanning direction. 17A-17B show this effect. In FIG. 17A, the overall X-ray source array shown at 935 is schematically shown as a linearly distributed X-ray source array, which is oriented with its longitudinal axis A parallel to the x direction. To. Therefore, in FIG. 17A, when the imaged object (eg, tooth 106) is placed at a certain distance in the y direction, the scanning direction is perpendicular to the z direction of the root-crown. Conversely, in FIG. 17B, the X-ray source array 935 is again configured as a linearly distributed X-ray source array, which is oriented with its longitudinal axis A perpendicular to the x direction. Therefore, in FIG. 17B, when the object to be imaged (for example, the tooth 106) is placed at a certain distance in the y direction, the scanning direction is parallel to the z direction of the root-crown.

FIG. 18 shows a method flow diagram showing an intraoral tomosynthesis method for 3D dental imaging using a fixed intraoral tomosynthesis system that includes the creation and display of synthetic two-dimensional (2D) intraoral images.

In the first step 1000A, the system startup and / or check is started. Launching and / or checking of the system to be initiated may be accomplished by a healthcare professional and / or dedicated computing specifically linked to a fixed intraoral tomosynthesis system and / or a method of 3D dental imaging. It may be robot controlled and / or automatically using the device. The dedicated computing device may be a device such as the computing platform 804 shown in FIG. In some embodiments, the system launch and / or check step may include initiating each component, including an X-ray detector, an X-ray array, a computing platform, and the like.

In the second step 1000B, the patient can check in. For example, a patient can check in and access a file containing patient information (eg, from the data storage device 812 of computing platform 804 in FIG. 8), which can be transferred to a fixed intraoral tomosynthesis system. You can upload it.

In the third step 1000C, the patient may be placed in a location where the detector attached to the detector holder can be placed inside the patient's mouth. For example, a patient is seated on a reclining seat and an intraoral detector attached to a detector or X-ray detector holder 910 (eg, FIG. 10) is placed close to the ROI (eg, one or more teeth) in the patient's mouth. Can be placed in the patient's mouth.

In the fourth step 1000D, the position of the detector holder can be adjusted to prepare the detector holder for alignment with the aiming cone. For example, the first end of the detector or X-ray detector holder 910 as shown in FIG. 10 may be prepared for attachment to the aiming cone 914 (see, eg, FIGS. 11A-11B).

In the fifth step 1000E, the X-ray detector holder may be coupled to the aiming cone. For example, the first end of the X-ray detector holder 910 is magnetically attached to the aiming cone 914 via the first end of the X-ray detector holder 910 and a plurality of magnets 906, 922 embedded in the aiming cone 914. May be combined.

In the sixth step 1000F, the system can be activated to acquire all projected images for 3D tomosynthesis (eg, to perform a tomosynthesis scan). For example, performing a tomosynthesis scan collects one or more X-ray projection images using X-ray radiation emitted from the corresponding focal point or pixel of an X-ray source array that can be spatially distributed. Can include that. In some embodiments, each of the X-ray pixels in the X-ray source array can be individually activated. In some embodiments, radiography and data acquisition are configured to be synchronized according to a pre-programmed imaging protocol. The pre-programmed protocol can include a set of steps performed by a computing platform (eg, 804 in FIG. 8) and its associated fixed intraoral tomosynthesis system programmed prior to the tomosynthesis scanning session. .. For example, the protocol is (a) a step that triggers the start of data collection of the intraoral detector by X-ray photons emitted from the first focal point, where the dwell time is the same as the X-ray irradiation time. And (b) after the dwell time, the X-ray emission from the first focal point is switched off and the data is transmitted to the computing platform by the intraoral detector for a fixed readout time. (C) At the end of the fixed readout time, the step of switching on the X-ray emission from the second focal point and starting the acquisition of the intraoral detector data again, and (d) the last X from the last focal point. It can include a step of repeating the process until a line projection image is recorded. In another example, the protocol (a) triggers the start of acquisition of intraoral detector data for each frame by X-ray photons emitted from the corresponding focal point and presets the dwell time for each of the frames. And (b) after each X-ray irradiation, the step of transmitting data to the computing platform by the oral detector, and (c) after each X-ray image acquisition of the frame, the oral detector is reset and finally. It involves repeating the process until the final X-ray projection image from the focal point of the photon is recorded. Other protocols may be included, as will be appreciated by those of skill in the art. In addition, the X-ray detector can be configured and / or designed for a particular protocol.

In a seventh step 1000G, image processing and reconstruction can be performed on a computing platform (eg, 804 in FIG. 8). For example, each of the image slices taken from each X-ray pixel can be reconstructed into a single tomosynthesis image on the computing platform 804. In some embodiments, the X-ray projection image acquired during the sixth step is from an intraoral detector (see FIG. 9) to, for example, an intraoral detector into a computing platform. It may be transmitted to the computing platform 804 via a connected wire data transmission line, wireless transmission, and the like.

In the eighth step 1000H, which may be optional, a 2D image can be synthesized from the 3D reconstructed image in the seventh step. For example, a 2D image may be synthesized from a projection direction that is the same as or different from the direction in which the one or more original X-ray projection images were collected.

In the ninth step 1000I, the reconstructed 3D image and, optionally, the 2D synthesized image can be stored in the database. For example, the database may be the data storage device 812 of FIG. 8 of a dedicated computing platform associated with a fixed intraoral tomosynthesis system.

In step 10 1000J, the reconstructed 3D image and / or optional 2D image can be displayed to any medical personnel and / or patient using a display. For example, the user accesses a data storage device 812 that stores the reconstructed 3D image and / or any 2D image and displays the reconstructed image on the display associated with the computing platform 804 of FIG. can do. In some embodiments, displaying a sequence of one or more synthetic X-ray projection images from different projection angles allows a healthcare provider, such as a dentist, to display close boundaries between one or more teeth. It can be advantageous as it can allow for better visualization of the surface. In some embodiments, one or more synthetic X-ray projection images are displayed simultaneously with one or more 3D tomosynthesis slice images (eg, 3D images used to reconstruct a 3D tomosynthesis image). , For example, it is possible to improve the characterization and diagnostic accuracy of diseases such as dental diseases.

It will be appreciated that the flowchart of the exemplary method of FIG. 18 is provided for illustration purposes only and that different and / or additional steps may be performed without departing from the scope of the subject matter described above. .. It will also be appreciated that the various steps described herein may be performed in different orders or sequences, or may be omitted in their entirety.

Although the diagrams for dental imaging have been described above, the systems, methods, and computer-readable media described above can be used for, but are not limited to, applications other than dental imaging. Therefore, the subject can be embodied in other forms without departing from its spiritual and essential characteristics. Therefore, the embodiments described above should be considered to be exemplary in all respects and not limiting. Although the subject matter has been described with respect to certain preferred embodiments, other embodiments apparent to those of skill in the art are also within the scope of the subject matter of the invention.

It is understood that various details of the subject matter described herein may be modified without departing from the scope of the subject matter described herein. Moreover, the above description is for purposes of illustration only and not limitation, as the subject matter described herein is defined by the claims.

Claims (14)

A fixed intraoral tomosynthesis system for three-dimensional (3D) imaging of objects.
Spatically distributed X-ray source arrays containing one or more focal points, and
A degree of freedom (DOF) device attached to the spatially distributed X-ray source array at the first end of the joint arm, wherein the first end of the joint arm is the object. The closest DOF device and
A control unit comprising a power source and a control electronic device configured to control the spatially distributed X-ray source array, which can be attached to the second end of the joint arm. A control unit that is connected to the spatially distributed X-ray source and can be mounted on a wall or surface, through the inside of the joint arm or via an electrical cable along the joint arm.
An intraoral detector configured to record one or more X-ray projection images, each of the one or more X-ray projection images being a spatially distributed X-ray source. An intraoral detector and an intraoral detector produced by X-ray radiation emitted from the corresponding focal point of the one or more focal points in the array.
The spatially distributed X-ray source array and the spatially distributed X-ray source array, which is a collimator arranged between the patient and the patient, are coupled to the intraoral detector. It comprises a collimator that limits X-ray radiation emitted from said one or more focal points of the spatially distributed X-ray source array to a common area defined by the intraoral detector.
The collimator
Aiming cone and
A first collimator plate disposed adjacent to the first end of the aiming cone in close proximity to the spatially distributed X-ray source array, comprising one or more openings, said opening. Each of the first collimators is configured to collimate the X-ray radiation emitted from the corresponding focal point of the one or more focal points of the spatially distributed X-ray source array. With the plate,
A second collimator plate located at the second end of the aiming cone in close proximity to the intraoral detector with a common opening configured for all of the one or more focal points. Equipped with a second collimator plate, including
The first and second collimator plates are such that the X-ray radiation of each of the one or more focal points is spatially dispersed X-ray source, the intraoral detector, or the first and second. / Or configured to collimate to a substantially common area on the surface of the intraoral detector without any mechanical movement of the second collimator plate.
The system is configured to perform tomosynthesis reconstruction and use the computing platform to generate one or more 3D images using the one or more X-ray projection images. Intraoral tomosynthesis system. The spatially distributed X-ray source array is rotatable about about three independent axes defined by the DOF apparatus in order to align the X-ray source array with the object. Item 1. The system according to Item 1. The system of claim 1, wherein the first and second collimator plates are disposed in a plane substantially parallel to each other on the aiming cone. The first collimator plate is fixed to the spatially dispersed X-ray source array and the second collimator plate is replaceable depending on the orientation and / or size of the intraoral detector. , The system according to claim 1. The system of claim 1, wherein the collimator is configured such that X-ray irradiation from each of the focal points is collimated to the intraoral detector within about 1% of the dimensions of the active detector region. The system of claim 1, wherein the spatially dispersed X-ray source array comprises an electroradiated X-ray source array based on carbon nanotubes. The intraoral detector digitally records the one or more X-ray projection images during one or more scans in synchronization with the X-ray irradiation from the spatially dispersed X-ray source array. A detector, each of the one or more X-ray projection images being the X emitted from the corresponding focal point of the one or more focal points of the spatially distributed X-ray source array. The system according to claim 1, which is generated by ray radiation. The one or more X-ray projection images are transmitted from the intraoral detector to the computing platform via a data transmission line connecting the intraoral detector to the computing platform or wireless transmission between them. The system according to claim 1, wherein the system is configured to be. The system is configured to perform a tomosynthesis scan, which comprises collecting the one or more X-ray projection images, including X-ray irradiation and the one or more X-ray projection images. Collecting is synchronized according to a pre-programmed protocol, said pre-programmed protocol.
The step of activating the first focus to radiate X-ray radiation for a certain X-ray irradiation time and triggering the acquisition of the intraoral detector data during a certain dwell time, wherein the dwell time is said. The step of activating and triggering, which has the same duration as the X-ray irradiation time,
After the dwell time, the first focal point is deactivated to stop the X-ray emission from the first focal point, and the intraoral detector data is read for a fixed reading time. The steps to send to the computing platform and
After the fixed read time, the second focus is activated to radiate X-ray radiation during the X-ray irradiation time, triggering subsequent acquisition of new intraoral detector data during the dwell time. Steps and
After the dwell time, the second focal point is deactivated in order to stop the X-ray emission from being emitted from the second focal point, and the new intraoral detector data is read at a fixed reading time. While sending to the computing platform,
The system of claim 1, comprising repeating the activation and deactivation steps until the last X-ray projection image from the last focus is acquired and transmitted to the computing platform. The system is configured to perform a tomosynthesis scan, the tomosynthesis scan comprising collecting the one or more X-ray projection images, X-ray irradiation and the one or more X-ray projections. Collecting images is configured to be synchronized according to a pre-programmed protocol, said pre-programmed protocol.
The X-ray irradiation is to trigger the acquisition of the intraoral detector data for each of the one or more X-ray projection images during a dwell time, the X-ray irradiation radiating from the corresponding focal point. The dwell time comprises the X-ray emission and the triggering step, which is preset for each of the one or more X-ray projection images.
After each X-ray irradiation, the step of transmitting the intraoral detector data to the computing platform and
After the acquisition of each of the one or more X-ray projection images, the step of resetting the intraoral detector and the end of the one or more X-ray projection images from the last focal point are acquired and transmitted. The system according to claim 1, further comprising a step of repeating the trigger, transmission, and reset steps. The control unit is configured to set the X-ray tube current to the same X-ray tube current for each of the one or more focal points.
The control unit is configured to apply an extraction voltage to the extraction gate for each corresponding focal cathode.
The system according to claim 1, wherein the X-ray irradiation level for each of the one or more X-ray projection images is set by changing the X-ray irradiation time. A fixed intraoral tomosynthesis system for three-dimensional (3D) imaging of objects.
Spatically distributed X-ray source arrays containing one or more focal points, and
A degree of freedom (DOF) device attached to the spatially distributed X-ray source array at the first end of the joint arm, wherein the first end of the joint arm is the object. The closest DOF device and
A control unit comprising a power source and a control electronic device configured to control the spatially distributed X-ray source array, which can be attached to the second end of the joint arm. A control unit that is connected to the spatially distributed X-ray source and can be mounted on a wall or surface, through the inside of the joint arm or via an electrical cable along the joint arm.
An intraoral detector configured to record one or more X-ray projection images, each of the one or more X-ray projection images being a spatially distributed X-ray source. An intraoral detector and an intraoral detector produced by X-ray radiation emitted from the corresponding focal point of the one or more focal points in the array.
The spatially distributed X-ray source array and the spatially distributed X-ray source array, which is a collimator arranged between the patient and the patient, are coupled to the intraoral detector. A collimator and a collimator that limits X-ray radiation emitted from the one or more focal points of the spatially distributed X-ray source array to a common area defined by the intraoral detector.
An X-ray detector holder configured to couple to the collimator at the first end of the X-ray detector holder and to the intraoral detector at the second end of the X-ray detector holder. The intraoral detector comprises an X-ray detector holder, which is attached to the second end of the X-ray detector holder and is configured to be placed inside the patient's mouth. , The first end of the X-ray detector holder is coupled to the exit window of the collimeter, a fixed intraoral tomosynthesis system. 12. A plurality of magnets are disposed on the surface of the first end of the X-ray detector holder and on the collimator to magnetically couple the X-ray detector holder to the collimator. The system described. 12. The system of claim 12, wherein the system is operated in a constant irradiation mode and the X-ray irradiation level is adjustable by varying the X-ray tube current for each of the one or more focal points. system.

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