JP7382042B2 - Fixed intraoral tomosynthesis imaging system, method, and computer-readable medium for three-dimensional dental imaging - Google Patents

Description

Detailed description of the invention

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application was filed on May 2, 2016, the contents of which are hereby incorporated by reference in their entirety.
Claims priority to U.S. Provisional Patent Application No. 62/333,614, filed on May 9th.
[Technical field]
The subject matter disclosed herein relates to radiography. More particularly, the subject matter disclosed herein provides fixed intraoral tomosynthesis systems, methods, and methods for three-dimensional dental imaging.
and on computer-readable media.
[Background technology]
Dental radiography has undergone significant changes over the past few decades. However, the need for more accurate diagnostic imaging methods continues to be a high priority. Intraoral dental x-rays were introduced only one year after Roentgen discovered x-ray radiation. Since that time,
Advances in dental imaging technology include more sensitive detector technology, panoramic imaging, digital imaging, and cone beam computed tomography (CBCT). Computed 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. This provides relatively high resolution, and limited field of view images for most routine dental needs. However, as a two-dimensional (2D) imaging modality, this technique suffers from superposition of overlapping structures and loss of spatial information in the depth dimension. Panoramic imaging is a common form of extraoral imaging that visualizes the entire maxilla, mandible, temporomandibular joint (TMJ) and associated structures within a single image, but with significant geometric distortion. However, the spatial resolution is relatively low compared to intraoral radiography. CBCT as a three-dimensional (3D) imaging modality has gained wide acceptance in the dental field, especially in surgical planning procedures such as dental implants and orthodontic treatment planning, and in the evaluation of endodontic and pathological conditions. However, compared to 2D radiography, there are several drawbacks associated with CBCT, among them excessive noise and artifacts from metal dental restorations/instruments, thereby reducing image quality. .
Compared to 2D radiography, acquisition, reconstruction, and interpretation times are significantly increased, thereby reducing clinical efficiency and increasing financial costs. Ionizing radiation doses are significantly higher, thereby increasing the patient's radiation burden.

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

Dental caries is the most common dental disease. The World Health Organization (WHO) estimates that 60% of children in school
It is estimated that ~90% and nearly all adults have cavities at some point. If dental caries lesions are detected early enough (eg, before cavitation), they can be removed and remineralized by non-surgical means. If carious lesions go undetected, they can develop into more serious conditions that may require extensive restorations, endodontic therapy, and even 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 reported sensitivities ranging from 40% to 70% for lesions within the dentin and 30% to 40% for lesions confined to the enamel. CBCT does not provide significant improvement in caries detection. Beam hardening artifacts and patient motion reduce structural sharpness and definition.

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

Dental radiography provides important information for assessing dental prognosis and making treatment decisions related to periodontal disease. Currently, two-dimensional intraoral X-ray photography is the mainstream of dental imaging. This provides a relatively high resolution image with a limited field of view for most routine dental needs. However, this technique is limited by the 2D representation of 3D objects. 2
D images result in a superposition of overlapping structures and a loss of spatial information in the depth dimension. As a result, important dimensional relationships are obscured, the observed clarity is reduced, objects of interest are lost, and pathological contrast is reduced. On the other hand, panoramic imaging
A common form of extraoral imaging that visualizes the entire maxillary, mandibular, temporomandibular joints and associated structures in a single scan. It is subject to significant geometric distortions and has a relatively low spatial resolution compared to intraoral x-rays.

These diagnostic challenges demonstrate the clinical need for diagnostic imaging systems with high resolution, 3D capability, reduced metal artifact sensitivity, and reduced radiation burden to the patient.
Digital tomosynthesis imaging is a 3D imaging technique that provides reconstructed slice images from a series of projection images at limited angles. Digital tomosynthesis is
Improves visibility of the anatomy by reducing visual clutter from overlying normal anatomy. Some examples of current clinical tomosynthesis applications include thoracic,
Includes abdominal, musculoskeletal and breast imaging.

In the late 1990s, a variation of tomosynthesis technology, the so-called Tuned Aperture Computed Tomograph, was developed for dental imaging.
y(TACT) was considered. 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 evaluation of impacted third molars. However, the caries results were inconclusive.

TACT was not adopted clinically because the technique was impractical for patient imaging. A conventional x-ray tube is a single pixel device from which x-rays are emitted from a fixed point (focal point). The X-ray source was mechanically moved around the patient to obtain multiple projection images. Fiducial markers were used to determine the imaging geometry. This process was time consuming (eg, approximately 30 minutes per scan) and required high operator skill to accomplish image acquisition. Difficulties in accurately determining parameters of imaging geometry and long imaging acquisition times due to mechanical motion of the X-ray source
becomes impractical. Both variations of TACT for 3D intraoral imaging using a single x-ray source have similar drawbacks and disadvantages.

Extraoral tomosynthesis has been investigated using experimental devices as well as in patient studies using CBCT. Extraoral geometries required higher radiation doses. Image quality was compromised by crosstalk of out-of-focus structures. To avoid high radiation doses,
Intraoral tomosynthesis using a single mechanically scanned X-ray source has been described in the patent literature and has been discussed in recent publications using a single conventional X-ray source and a rotating phantom. Unfortunately, the limitations mentioned above for TACT are also the same in these methods, which are mainly caused by conventional single-focus X-ray tubes and therefore have the same spatial resolution as conventional 2D intraoral dental imaging. What is needed is a fixed intraoral tomosynthesis system, method, and computer-readable medium for 3D dental imaging that can rapidly obtain 3D dental images at comparable radiation doses to the patient.
[Summary of the invention]
The subject matter of the present disclosure relates to generating three-dimensional (3D) tomosynthesis images of objects, particularly images 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 includes one or more spatially distributed focal points. an x-ray source array and a degree of freedom (DOF) device attached to the spatially distributed x-ray source array at a first end of the articulated arm, the first end of the articulated arm being targeted; A control unit comprising a degree of freedom (DOF) device located proximate to an object, a power supply, and control electronics configured to control a spatially distributed x-ray source array, the control unit comprising: attachable to the second end of the articulating arm and connected to a spatially distributed x-ray source via electrical cables through or along the inside of the articulating arm and mounted on a wall or surface; a control unit and an intraoral detector configured to record one or more X-ray projection images, each of the one or more X-ray projection images being spatially distributed; an intraoral detector, a spatially distributed x-ray source array, and a patient, the x-ray source array being disposed of the a collimator disposed between one or more of the spatially distributed x-ray source arrays, the collimator coupling the spatially distributed x-ray source array to the x-ray detector; a fixed intraoral tomosynthesis system comprising: a collimator configured to confine 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 to generate one or more 3D images using the one or more X-ray projection images using a computing platform. Ru.

According to another aspect of the subject matter herein, the 3 using a fixed intraoral tomosynthesis system
1. A method for D-imaging comprising: positioning a spatially distributed X-ray source array of a fixed intraoral tomosynthesis system outside a patient's mouth; a source array comprising one or more focal points spatially distributed over one or more anodes; and an x-ray detector holder configured for at least one imaging protocol. placing an x-ray detector inside the patient's mouth using a placing the first collimator plate on the first end of the collimator and the second collimator plate on the second end of the collimator; providing at the end a second collimator plate;
providing a spatially distributed array of x-ray sources and collimators selected to correspond to one or more aspects of the x-ray detector holder for at least one imaging protocol; coupling the X-ray detector holder through the second collimator plate by coupling two collimator plates onto the second end of the collimator and the first end of the X-ray detector holder; Obtain one or more X-ray projection images of the patient's mouth from one or more viewing angles by sequentially activating each of the one or more focal points to a preset radiation dose and X-ray energy acquiring, the one or more X-ray projection images being two-dimensional (2D);
transmitting one or more X-ray projection images to a computing platform; and converting one or more 3D images from the one or more X-ray projection images using one or more iterative reconstruction algorithms. reconstructing the tomosynthesis images; processing the one or more 3D tomosynthesis images; and displaying the one or more 3D tomosynthesis images on one or more monitors electrically connected to a computing platform. A method is provided, comprising the steps of:

According to yet another aspect of the subject matter herein, a non-transitory computer-readable medium includes computer-executable instructions that, when executed by a processor of a computer, control the computer to perform a method, the method comprising: the step of positioning a spatially distributed x-ray source array of a fixed intraoral tomosynthesis system on a first side of the object or outside the patient's mouth, the step comprising: The X-ray source array includes one or more focal points and is positioned on a second side of the object or patient using an X-ray detector holder configured for at least one imaging protocol. placing an x-ray detector inside the mouth of the person, the x-ray detector holder comprising a plurality of magnets disposed on a first end of the x-ray detector holder; positioning the first collimator plate with the first end of the collimator located on a first side of the object or outside the patient's mouth;
providing a second collimator plate at the second end of the collimator, the second collimator plate being adapted to one or more of the X-ray detector holders for at least one imaging protocol; providing a spatially distributed array of x-ray sources and a collimator, the second collimator plate being selected to accommodate a plurality of modalities; coupling to the X-ray detector holder via a second collimator plate by coupling onto the first end of the holder; and coupling each of the one or more focal points to a preset radiation dose and acquiring one or more X-ray projection images of the object or patient's mouth from one or more viewing angles by sequentially activating the one or more X-ray projections to energy; The images are two-dimensional (2D) acquired, transferred to a computing platform, and one or more iterative reconstruction algorithms are used to obtain the images. reconstructing one or more 3D tomosynthesis images from the one or more X-ray projection images; processing the one or more 3D tomosynthesis images; displaying the non-transitory computer-readable medium on one or more monitors electrically connected to the computer-readable medium.

While some of the aspects of the subject matter disclosed herein are described herein above and are accomplished in whole or in part by the subject matter disclosed herein, other aspects may be seen in the accompanying drawings. As the description progresses, it will become clearer as the description progresses, and is best explained herein below.

The features and advantages of the present subject matter will be more easily understood from the following detailed description, which should be read in conjunction with the accompanying drawings, which are given by way of illustrative and non-limiting example only.
FIG. 1 is a perspective view of an exemplary embodiment of an intraoral tomosynthesis system with a fixed linkage between an x-ray source and an x-ray detector in accordance with the disclosure herein. FIG. 2A is a top view of a fixed linkage between the X-ray source and X-ray detector of FIG. 1 in accordance with the disclosure herein. FIG. 2B is a top perspective view of a receptacle between an X-ray source and an X-ray detector in accordance with the disclosure 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, and FIG. 3B is a front perspective view of the geometry calibration device of FIG. 3A, according to the disclosure herein. FIG. 3 is a rear perspective view of an exemplary embodiment of the device. FIG. 4 is an example image capture illustrating a process for determining tomosynthesis imaging geometry using the example geometry calibration apparatus of FIGS. 3A-3B in accordance with the disclosure herein. 5A, 5B, 5C, and 5D are schematic diagrams illustrating an exemplary geometry calibration apparatus for an intraoral tomosynthesis system according to the disclosure herein. 6A, 6B, and 6C are schematic diagrams illustrating exemplary light patterns using the geometry calibration apparatus of FIGS. 5A-5D in accordance with the disclosure herein. FIG. 7 is a schematic diagram illustrating an exemplary embodiment of a geometry calibration device for an intraoral tomosynthesis system according to the disclosure herein. FIG. 8 is a schematic system diagram illustrating an example embodiment of a fixed intraoral tomosynthesis system for three-dimensional (3D) dental imaging interfacing with an example computing platform in accordance with the disclosure herein. be. FIG. 9 is a diagram of a fixed intraoral tomosynthesis system for 3D dental imaging having an articulated arm with a degree of freedom device at one end and electronics and a power source at another end according to the disclosure herein. 1 is a perspective view of an exemplary embodiment; FIG. FIG. 10 is a perspective view of an exemplary holder embodiment for an X-ray sensor and/or detector in accordance with the disclosure herein. 11A and 11B are detailed perspective views illustrating an exemplary embodiment of magnetic coupling of the detector holder to the collimator of FIG. 10 in accordance with the disclosure herein. FIG. 12 is a perspective view of an exemplary embodiment of a collimator having a first X-ray limiting collimator plate and a second X-ray limiting collimator plate in accordance with the disclosure herein. FIG. 13 is a perspective view of the first x-ray limiting collimator plate of FIG. 12 in accordance with the disclosure herein. FIG. 14 is a schematic diagram of an exemplary collimator that collimates an x-ray beam from each focal point to a detector region in accordance with the disclosure herein. FIG. 15 is a perspective view of an exemplary embodiment of a degree of freedom device with three degrees of freedom of rotation in accordance with the disclosure herein. FIG. 16 is a perspective view of an exemplary embodiment of a linear x-ray source array according to the disclosure herein. FIG. 17A shows a linear X-ray source array for an exemplary embodiment of an X-ray sensor and/or detector in which the scanning direction is substantially perpendicular to the root-coronal direction, according to the disclosure herein. FIG. 17B is a schematic illustration of relative orientations of an exemplary X-ray sensor and/or detector, such that the scanning direction is substantially parallel to the root-coronal direction, according to the disclosure herein. 2 is a schematic diagram of the relative orientation of a linear x-ray source array for an embodiment; FIG. FIG. 18 illustrates a fixed intraoral tomosynthesis method for 3D dental imaging using a fixed intraoral tomosynthesis system, including creating and displaying a synthetic two-dimensional (2D) intraoral image, in accordance with the disclosure herein. 2 is a schematic diagram using a flowchart of an exemplary embodiment; FIG.

The subject matter of the present disclosure relates to fixed intraoral tomosynthesis systems, methods, and computer-readable media for three-dimensional (3D) dental imaging applications, although such fixed intraoral tomosynthesis systems, methods, and computer-readable media It will be understood by those skilled in the art that it may be used for applications other than dental imaging. For example, the system described herein may be described in U.S. Pat.
, 751,528, fixed digital breast tomosynthesis (
s-DBT) system. In particular, the fixed design of the s-DBT system increases the spatial resolution of the system by eliminating image blur caused by X-ray tube motion. Additionally, faster scan times are achieved through integration with high frame rate detectors to minimize patient motion and discomfort under compression. The fixed design of the s-DBT system, with no mechanical motion constraints, also allows for wider angle tomosynthesis scans for deeper resolution without changing the scan time.

In some aspects, the fixed intraoral tomosynthesis systems, methods, and computer-readable media described herein are used for dental imaging applications. In particular, fixed intraoral tomosynthesis systems may be used for intraoral imaging applications using an x-ray detector placed inside the patient's mouth. In other aspects, fixed tomosynthesis systems 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 may be utilized in dual energy applications. For example, two complete sets of X-ray projection images can be acquired for each object imaged. a first set can be collected at a first x-ray energy, a second set can be collected at a second x-ray energy,
At this time, the first X-ray energy is different from the second X-ray energy. According to one such aspect, two sets of X-ray images are acquired at two different X-ray anode voltages and then processed, reconstructed, and subtracted to identify specific features, such as dental caries. Emphasize the contrast. According to another such aspect, two projection images may be acquired at each viewing angle, one at a first X-ray energy and the other at a second X-ray energy.

Accordingly, the subject matter of the present disclosure provides fixed intraoral tomosynthesis systems, methods, and computer-readable media for 3D dental imaging. According to some embodiments, fixed intraoral tomosynthesis systems, methods, and methods for 3D dental imaging
and a computer-readable medium for moving an x-ray source, an x-ray detector for positioning inside a patient's mouth, a geometry calibration device, and an x-ray source, an x-ray detector, or a region of interest (ROI). and control electronics for obtaining multiple projections of the ROI of an object within the patient's mouth (eg, teeth) without the need for a patient's mouth. FIG. 1 depicts one such embodiment of an intraoral tomosynthesis system, indicated generally at 100. System 100 includes an X
A radiation source, an x-ray detector 120, a control unit, generally indicated at 130, a collimator, indicated generally at 140, and an x-ray detector holder 150 may be included. In some aspects, system 100 may be mounted so that it is immovable. For example, system 100:
It can be mounted from the ceiling, wall, etc. In other aspects, system 100 may be mobile. For example, system 100 may include wheels and be placed on a moving cart, hand truck, stand, etc. FIG. 1 shows a mobile cart, generally designated 102, with a system 100 attached thereto, using a mechanical arm, generally designated 104.
Mechanical arm 104 may be rotationally and/or axially movable about a pivot or hinge joint to adjust the position of system 100 about the object being imaged. Thus, by using the moving cart 102 and mechanical arm 104, the system 100 is free to move and rotate for optimal placement relative to the object. Optionally, mobile cart 102 can include a rechargeable battery (not shown) that can provide power for imaging, thereby connecting electrical cords and/or wires to power system 100. reduce the need for

X-ray source 110 may be configured to direct an x-ray beam (eg, 108 in FIG. 2A) toward a location or location where an ROI of an object (eg, a patient's teeth) is located. X
The line beam can be directed to the location or position from several different angles. Furthermore, the X-ray source 110, the X-ray detector 120, and the object can be arranged such that the generated X-ray beam is detected by the X-ray detector 120. In some aspects, the x-ray source 110 is a spatially distributed x-ray source positioned such that the generated x-ray beam is directed substantially toward the object and passes through the ROI of the object. array (e.g. 310 in Figure 3A)
can be provided. In some aspects, different ROIs of an object can be imaged during one or more imaging sessions, so that the ROI of the object can change.

In some aspects, the x-ray source array of x-ray source 110 may include a plurality of individually programmable x-ray pixels (eg, 312 in FIG. 3A) distributed as a linear array. Alternatively, the x-ray pixels are arranged non-linearly along the x-ray source 110, e.g.
They may be distributed in a polygon, a two-dimensional matrix, or the like. In some aspects, the x-ray pixels in the array are uniformly spaced to direct the x-ray beam toward an ROI of the object;
and/or may be tilted. In any case, the x-ray pixel may be placed at any suitable location such that the x-ray beam is substantially directed onto the object and detected by the x-ray detector 120. In particular, the X-ray source 110 and the X-ray detector 120 may be fixed relative to each other during irradiation of the object by the X-ray source 110 and during detection by the X-ray detector 120. X-ray source 1
10 are configured to activate (e.g., by control unit 130) sequentially (e.g., one pixel at a time) for a given dwell time and a given x-ray dose level.
can be controlled.

In some aspects, the x-ray source array of x-ray source 110 may include, for example, between 10 and 100 pixels, particularly 25 pixels. Each pixel is, for example, XinRay Sy
stems Inc. a carbon nanotube (CNT) field emission-based cathode and a gate electrode for extracting electrons, such as those commercially available from manufacturers including;
and a set of electron focusing lenses (eg, Ein-Zel type electrostatic focusing lenses) to focus the field emission electrons to a small area or focal point on the target (eg, the anode). In particular, the CNT cathode is a cold cathode and can be turned on and off instantaneously. Using a CNT cathode in this manner reduces the warm-up time and heat generation of the X-ray source 110 compared to conventional vacuum electronics based on hot cathodes (e.g., cathode ray tubes, microwave tubes, can be reduced. Alternatively, each pixel can include a hot cathode, a photocathode, etc.

In some aspects, if the x-ray source pixels are arranged linearly parallel to the detector plane rather than in an arc, the distance from the pixel to the x-ray source may vary from pixel to pixel. To compensate for such variations in the x-ray beam travel distance, the x-ray tube current from each pixel is individually controlled (e.g., by control unit 130) such that the magnetic flux strength at the phantom surface remains the same. and can be adjusted.

The size of the focus 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. Focus is approximately 0.05mm
The size can range from 2 mm to 2 mm. System 100 may be designed for an isotropic 0.2×0.2 mm effective focal spot size for each x-ray source pixel. Individual focal spot size can be adjusted by adjusting the potential (eg, voltage) of the focusing electrode. In order to minimize current fluctuations and delays and also reduce pixel-to-pixel variation, an electrical compensation loop is incorporated to automatically adjust the gate voltage to maintain a constant preset emission current. Can be done. The area of the CNT cathode is approximately 10 m with an effective focal size of 0.2 x 0.2 mm.
can be selected to obtain a peak x-ray tube current of A. In particular, higher X-ray peak currents of 50-100 mA can be obtained by increasing the CNT area and focal spot size.

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

X-ray detector 120 can be configured to collect projection images of the object from different angles for tomosynthesis. To do so, housing 132 of system 100
A control unit 130, which may be housed within a control unit 130, is capable of controlling electron radiation spatially distributed over a region of the x-ray source 110 (e.g., on one or more anodes within a vacuum chamber), as described herein. The x-ray source array of pixels can be configured to be activated sequentially for a predetermined exposure time, radiation dose, and x-ray energy to adjust the intensity of the x-ray flux from each focal point. X
The source 110 may be electronically interfaced with an X-ray detector 120 so that projection images are recorded from the radiation originating from each focal point. In particular, control unit 130
is based on the distance between the x-ray source array of the x-ray source 110 and the object, by directly reading the radiation from each focal point, reading the x-ray tube current, or reading the cathode current. The intensity can be varied. In this way, the amount of x-rays delivered to the object from every viewing angle is substantially the same.

In some aspects, the size of each focal spot and/or the x-ray flux produced by x-ray source 110 may be adjusted by control unit 130. For example, control unit 1
30 that the X-ray source 110 increases the carbon nanotube area and focal spot size with up to 100 kVp and up to 10-20 mA tube current for each focal spot, and with focal spot 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. In some aspects, control unit 13
0 can also adjust the individual focus size by adjusting the potential of the focusing electrode. In some aspects, the control unit 130 minimizes current fluctuations and eliminates pixel-to-pixel variations by incorporating an electrical compensation loop to adjust the gate voltage to maintain a constant preset emission current. can be reduced.

A collimator 140 can be placed between the window of the x-ray source 110 and the detector 120 to confine the x-ray radiation to the ROI of the object. In some aspects, the first collimator 140
The end of the collimator 140 can be fixed to the X-ray source 110 and the second end of the collimator 140 can be configured to be foldable and/or tapered in the direction of the detector 120.

In some embodiments, a mechanical fixture (eg, x-ray detector holder 150) can be mounted to connect x-ray source 110 to x-ray detector 120 at a known, fixed location. Thus, at all times the position of the X-ray source 110 relative to the X-ray detector 120 can be known and maintained. Alternatively, the position of the x-ray focus relative to x-ray detector 120 need not be determined by the physical connection between x-ray detector 120 and x-ray source 110. Instead, a geometry calibration device may be utilized to determine the position of the x-ray source 110 relative to the x-ray detector 120 and thereby detect the position of the x-ray focal point relative to the x-ray detector 120.

Referring now to FIG. 2A, a more detailed diagram of 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 holder 150 is connected to the X-ray source 1 at a known distance from each other.
10 is fixed to an X-ray detector 120. In some aspects, a first end of X-ray detector holder 150 is secured to X-ray source 110 and a second end of X-ray detector holder 150 is secured to X-ray detector 120. In some aspects, the x-ray source array of x-ray source 110 includes a plurality of pixels, each of which is positioned at a known location and configured to point at a known angle inward toward the object. 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 focus produced by the X-ray source array pixel with respect to the X-ray detector 120 is Known.

For example, in FIG. 2A, the X-ray source 110 and X-ray detector 120 are
are fixedly separated by a distance D. In this example, the x-ray source 110 comprises a linear x-ray source array, and the x-ray source detector 120 includes an intraoral detector for placement within the patient's mouth to image the patient's teeth, generally indicated at 106. It is constructed as a vessel. X-ray detector 120 may be placed behind a particular ROI of tooth 106. Accordingly, when the x-ray source 110 is activated, an x-ray beam, generally designated 108, may be generated and projected through the ROI of the tooth 106 onto the x-ray detector 120. Since the distance D is a fixed and known quantity, the exact location of the focus produced by the x-ray source array pixel relative to the x-ray detector 120 is known. In this way, 2D
The reconstruction of the projection image into a 3D image can be improved.

Referring to FIG. 2B, an alternative approach using an x-ray detector holder 150 is shown. In particular, apparatus generally designated 200 may be utilized to connect an x-ray source (eg, 110) to an x-ray detector (eg, 120) at a known distance from each other. In some aspects, device 200 can include a receptacle 210 that is attachable to an x-ray source and connectable with a coupling arm 220 that is attachable to an x-ray detector. When device 200 is used in an intraoral tomosynthesis system (e.g. 100), receptacle 210 may be attachable to an X-ray source (e.g. 110) and connecting arm 2
20, the coupling arm may be magnetically coupled to an intraoral X placed in the patient's mouth.
It may be attachable to a line detector (eg, 120).

In some aspects, receptacle 210 is made of any suitable material, such as any metal or metallic material (e.g., aluminum (Al), steel, iron (Fe), alloys thereof, etc.), any non-metallic material ( (e.g., plastics, polymers, etc.), non-magnetic materials, magnetic materials, and/or any combination thereof. Receptacle 210 can include a metal receptacle configured to attach to an x-ray source. Receptacle 21
0 may include a hollow interior, generally designated 212, to allow for collimation of the x-ray radiation from the x-ray source array. For attachment to coupling arm 220, receptacle 210 can include an angled channel, generally designated 214, disposed along the outer side. Channel 214 may be disposed along the entire length of receptacle 210 and may be correspondingly sized and shaped to receive a raised inner surface 228 of longitudinal portion 222 of coupling arm 220.

In some aspects, the connecting arm 220 is made of any suitable material, such as any metal or metallic material (e.g., aluminum (Al), steel, iron (Fe), alloys thereof, etc.), any non-metallic material. (e.g. plastics, polymers, etc.), non-magnetic materials, magnetic materials, and/or
or any combination thereof. For example, coupling arm 220 can include a magnetic longitudinal portion 222, an elbow 224, and an x-ray detector holder 226. A first end of the elbow 224 may be disposed toward one end of the longitudinal section 222 and extend perpendicularly therefrom, thereby forming a right angle therewith. An X-ray detector holder 226 can be disposed at the second end of the elbow 224;
The X-ray detector (eg, 120) can be configured to be held stationary. When the X-ray detector is an intraoral X-ray detector, the X-ray detector holder 226 is configured to provide an intraoral
The line detector may be configured for fixed placement.

The longitudinal portion 222 of the coupling arm 220 can include a raised inner surface 228 that can be sized and shaped to be removably received within the channel 214 of the receptacle 210. In some aspects, connection arm 220 can be configured to be attached to and moved out of receptacle 210 via a magnetic mount. For example, the magnetic fixture may be connected to channel 21
4 and the raised inner surface 228 of the longitudinal portion 222 may include metal contacts, generally designated 216, along the length of one or both of the raised inner surfaces 228 of the longitudinal portions 222. Metal contacts 216 can be configured to provide immediate feedback regarding the accuracy of alignment and coupling between channel 214 and inner surface 228. Additionally, such contacts 216 may enable a quick release function of the device 220, which may be useful, for example, if the patient suddenly moves.

3A-3B, a first exemplary implementation of a geometry calibration apparatus, generally designated 300, for use in an intraoral tomosynthesis system comprising an x-ray source 310 and an x-ray detector 320. The form is indicated. The geometry calibration device 300 includes, for example, a plate or screen 330, at least one light source 340, a camera 350, at least one gyroscope 360, or any other device configured to calculate and/or detect orientation and rotation. and other devices.

In some aspects, the position of X-ray detector 320 relative to X-ray source 310 may be fixed, even in embodiments where X-ray source 310 and X-ray detector 320 are not physically coupled to each other. For example, in FIGS. 3A and 3B, the x-ray source 310 and x-ray detector 320 are
It is not physically separated by a mechanical linkage, such as the X-ray detector holder 150 of FIG. 2B, illustrating that a fixed position of the X-ray source relative to the X-ray detector can be maintained otherwise.
Rather, the X-ray source 310 and the X-ray detector 320 may be physically separated from each other such 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. , which will be explained in more detail below.

In some aspects, the x-ray source 310 can include an x-ray source array 312, shown generally at 312, that includes individually programmable x-ray pixels 314. As shown in the exemplary embodiment of FIG. 3A, 5 to 20 pixels 314 may be distributed in a substantially linear array and are configured to project X-rays onto an X-ray detector 320. Often, a projection image of the ROI of the object (eg, a patient's teeth) is thereby generated. However, the X-ray source 310 and
Since the ray detectors 320 are not physically coupled to each other, the geometry calibration device 300 may be utilized to geometrically calibrate the position of the x-ray detectors 320 relative to the x-ray source 310.

In some aspects, the at least one light source 340 projects a light beam, generally designated 342, onto the plate 330 to determine the translational position of the plate 330 relative to the x-ray source 310. A light spot shown in can be generated. In some aspects,
An x-ray detector 320 can be physically coupled to plate 330. For example, crossbar 322 can be used to secure X-ray detector 320 to plate 330. Crossbar 322 can have a length, for example, between about 2 cm and 20 cm. In some aspects, the length of crossbar 322 can be adjusted. The plate 330 is
For example, it can include paper, plastic, metal or any combination of such materials with approximate dimensions from about 5 cm and 20 cm. In some aspects, crossbar 322 can secure plate 330 to x-ray detector 320 such that plate 330 is in a plane parallel to the plane in which x-ray detector 320 is. In other aspects, plate 330 may be angled relative to x-ray detector 320.

In some aspects, when detector 320 is configured as an intraoral x-ray detector, plate 330 can protrude from the patient's mouth. In this way, the plate 330 can be coupled to the X-ray detector 320 at a known, fixed distance such that determining the angular and translational position of the plate 330 with respect to the X-ray source 310 320
position can be determined.

In some aspects, at least one light source 340 can be projected onto plate 330. For example, at least one light source 340 may comprise a low power laser or other light configured to project onto plate 330, such as a 5 mW laser pointer with a wavelength of 650 nm. At least one light source 340 includes X-ray source 310 and/or
or may be attached to a collimator or otherwise attached. Figures 3A to 3B
As shown in , the illustrated embodiment has four light sources 340, each of which
located in a separate corner of the Each of the four light sources 340 is tilted toward the plate 330 to project a light beam 342 onto the plate 330, thereby creating four separate light spots 344 (see, e.g., 344A-D in FIG. 4). can do. 4 light sources 3
Depending on the angle of incidence at which each of 40 is directed onto plate 330, light spots 344 can form a rectangle, square, triangle, or any other shape, with each projected light beam 342 having a A light spot 344 is produced that forms the corner apex of such projected shape. In some aspects, 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 relative to the x-ray source 310. In particular, as a result of arranging at least one light source 340 in this way, plate 33
The shape formed by the light spot 344 produced from the projected light beam 342 on
It becomes larger as it approaches the source 310.

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

In some embodiments, at least one gyroscope 360 is included to
The angular position of plate 330 relative to 10 can be determined. For example, at least 1
The gyroscope 360 is manufactured by Parallax Inc., for example. Parallax Gyroscope Module 3-axis L3G4 commercially available from manufacturers including
200D. Therefore, determining the angular position of plate 330 with respect to X-ray source 310 can be accomplished with one of several techniques. for example,
The first technique involves attaching a first gyroscope 360 to the x-ray source 310 and a second gyroscope (not shown) to the plate 330 and transmitting data points from each gyroscope at a computing platform. and comparing. In another example, the second technique includes resetting plate 330 by placing plate 330 in the same plane as x-ray source array 310 and resetting plate 330 by placing plate 330 in the same plane as x-ray source array 310 and It can include resetting the data and measuring deviations from the initial x-ray source plane during the imaging process.

Referring now to FIG. 4, an exemplary image capture from a camera (e.g., 350)
A light beam 342 projects onto the plate 330 and produces a light spot shown generally at 344A-D.
shows the resulting captured image. In this example, from a light beam 342 generated from four separate light sources 340 arranged similarly as described above with reference to FIGS. 3A-3B,
Four separate light spots 344A-D are produced, each light spot 344A-D forming one corner of the rectangular shape or a vertex of the rectangular shape. The coordinate system is the X-ray detector 3 relative to the X-ray source 310.
may be defined to establish the x, y, and z directions to determine the 20 translational positions.
In some aspects, the distance between each light spot can determine the z-offset of plate 330 with respect to x-ray source 310. For example, the horizontal or x distance b _x measured between the first light spot 344A and the second light spot 344B, or the second light spot 344B and the third light spot 344C.
The vertical or y distance b _y of plate 330 relative to X-ray source 310 is measured between
Therefore, the z-offset of the X-ray detector 320 can be determined. This is because the distance between the light spots 344A-D is uniquely determined by the specification of any diffraction grating attached to the at least one light source 340, the wavelength of the at least one light source 340, and the z-offset. be. In other aspects, the distance from the light spot to the edge of plate 330 and
The ratio of the distance between opposing edges of 30 can determine the x- or y-offset of plate 330 with respect to x-ray source 310. For example, from the light spot 344D to the plate 33
The ratio of the horizontal or x distance a _x to the edge of the plate 330 to the horizontal or x distance c _x between two opposite edges of the plate 330 (e.g., a _x /c _x ) is the ratio of the horizontal or x distance a x to the edge of the plate 330 relative to the Therefore, the x-offset of the x-ray detector 320 can be determined. In another illustrative example, the ratio of the vertical or y distance a y from light spot 344D to the edge of plate 330 to the vertical or y distance c _y between two opposing edges of plate 330 (e.g. _, a _y /c _y ) is the X-ray source 31
The y-offset of the plate 330 and therefore the X-ray detector 320 relative to 0 can be determined.

5A-5D, a second diagram of an exemplary geometry calibration apparatus 500, generally designated 500, for use in an intraoral tomosynthesis system including an x-ray source 510 and an x-ray detector 520, is shown in FIGS. An embodiment is shown. Here, an exemplary sequential acquisition of tomographic images using a geometry calibration device 500 is shown. FIG. 5A shows a geometry calibration device 500
5B-5D show the initial setup of the
B - shows the sequential activation of different cathodes in the array of the X-ray source in the first position shown in FIG. 5C and the second position shown in FIG. 5D). 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, apparatus 500 may be configured in an initial configuration prior to acquiring 2D projection images. Although the position of X-ray detector 520 relative to X-ray source 510 may be fixed, in this embodiment, X-ray source 510 and X-ray detector 520 are shown as not being physically coupled to each other. Therefore, a mechanical linkage is provided between the x-ray source 510 and the x-ray detector 520.
There is no connection between them, and no fixed separation is maintained between them. Rather, the x-ray source 510 and x-ray detector 520 are
are physically separated from each other such that their relative positions can be dynamically determined by geometry calibration techniques, which will be explained in more detail below.

In some aspects, the x-ray source 510 can include an x-ray source array, generally designated 512, that includes individually programmable x-ray pixels 516. As shown in FIGS. 5A-5D, nine pixels 516 may be distributed in a linear array, and these pixels are connected to the x-ray beam, generally designated 514 (see, e.g., FIGS. 5B-5D). can be configured to be projected onto the x-ray detector 520 to generate a projected image of the ROI of the object 502 (eg, a patient's teeth). However, since the X-ray source 510 and the X-ray detector 520 are not physically coupled to each other, the geometry calibration device 500 is utilized to geometrically calibrate the position of the X-ray detector 520 relative to the X-ray source 510. can do.

In some aspects, X-ray detector 520 may be physically coupled to plate 530.
For example, crossbar 522 can be used to secure X-ray detector 520 to plate 530. Crossbar 522 can have a length, for example, between about 2 cm and 20 cm. In some aspects, crossbar 522 is adjustable in length. Plate 530 can include, for example, paper, plastic, metal, or any combination thereof. In some aspects, crossbar 522 can secure plate 530 to x-ray detector 520 such that plate 530 is in a plane parallel to the plane in which x-ray detector 520 lies. In other aspects, plate 530 may be angled relative to x-ray detector 520.

In some aspects, when detector 520 is configured as an intraoral x-ray detector, plate 530 can protrude from the patient's mouth. Thus, plate 530 can be coupled to X-ray detector 520 at a known, fixed distance (e.g., using crossbar 522), thereby determining the angular and translational position of plate 530 relative to X-ray source 510. Accordingly, the position of the X-ray detector 520 with respect to the X-ray source 510 can be determined. Plate 5
30 is paper, plastic, metal, etc., having approximate dimensions between 5 cm and 20 cm, for example.
or may be made from any combination of such materials.

The light source 540 is configured to project a beam of light, generally designated 542, onto the plate 530 to produce a spot of light, generally designated 544, to determine the translational position of the plate 530 relative to the x-ray source 510. Can be done. In some aspects, only one light source 540 may be required compared to the first embodiment of geometry calibration device 300. Light source 540 may be attached to or otherwise attached to x-ray source 510 and/or a collimator (not shown). In some aspects, light source 540 is integral with camera 550 and both can be configured to be attached to x-ray source 510. As shown in FIGS. 5A to 5D,
A light source 540 is attached to the camera 550 and may be mounted in the center of the x-ray source 510 adjacent its front edge. In particular, light source 540 may comprise a low power laser or other light configured to project onto plate 530, for example a 5 mW laser pointer with a wavelength of 650 nm.

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

In some aspects, camera 550 can record the position of light spot 544 projected onto plate 530 to determine the translational position of plate 530 with respect to x-ray source 510.
In some aspects, camera 550 can also be configured to provide motion tracking and correction during the imaging procedure if there is unintended movement of object 502 or system (eg, system 100). Camera 550 can include, for example, a high-resolution, high-speed digital camera that can be mounted at a known location on x-ray source 510 or a collimator (not shown). As discussed above, the camera 550 similarly has an X-ray source 540 centered on the X-ray source 510.
It can be mounted adjacent the front edge of the source 510. In some aspects, camera 550 sends captured photographic images to a computing platform (e.g., 804 in FIG. 8).
). For example, camera 550 may point light spot 5 on plate 530.
A photographic image capturing the position of 44 can be sent to a computing platform to determine the translational position of plate 530 relative to x-ray source 510, thereby determining the position of x-ray detector 520 relative to x-ray source 510. do.

Accordingly, the light source 540 and the camera 550 are tilted towards the plate 530 to project a light beam 542 onto the plate 530 through the at least one diffraction grating, thereby placing a light spot 544 at different positions on the screen 530 (e.g., 6A to 544 in Figure 6C
(see A-C), thus providing a light pattern on the screen 530. In particular, different positions of light source 540 and/or screen 530 may result in different light patterns, each of which is captured by camera 550 and changes the geometry of screen 530 and attached X-ray detector 520. X-ray source 51
It can be used to calibrate for each pixel within 0.

When apparatus 500 is configured and ready to generate 2D projection images, camera 550 captures the initial light produced by light source 540 (e.g., a laser) when X-ray detector 520 and screen 530 are in the first position. A computing platform (e.g. 804
). For example, camera 550 may include X-ray detector 520
and can be configured to capture light spots 544 forming an initial light pattern on screen 530 when screen 530 is in an initial or first position.
Processing of this captured image can be used as a reference for geometry calibration.

5B-5D, the acquisition of 2D projection images is shown, where the X-ray source 5
Each pixel 516 in the ten x-ray source arrays 512 is sequentially activated when the x-ray detector 520 and screen 530 are in a first position and then in a second position. Although FIGS. 5B-5D illustrate sequential activation of only three pixels 516 and only two different locations, those skilled in the art will appreciate that these figures are merely illustrative and non-limiting. You will recognize it.
For example, each pixel 516 within the x-ray source 510 can be activated and the detector 520 configured to record the resulting image. As shown in FIGS. 5A-5D, if there are nine pixels 516, all nine pixels 516 can be activated individually, and the X-ray detector 520 A respective image for each position of the X-ray detector 520 can be configured to be recorded. In some embodiments, the X-ray detector 5
20 need only be in one position, in which case the nine pixels 516 only need to be activated once, and the activation of each pixel 516 is performed individually. 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 multiple positions. be done.

In FIG. 5B, a second pixel 516A in the x-ray source 510 is shown in an activated state for producing an x-ray beam 514 that projects onto the detector 520, which is located on the screen 530. and record the projected image while the X-ray detector 520 is in the first position. In particular, before the second pixel 516A in the x-ray source 510 is activated, the pixel 51 in the x-ray source 510
The first of 6 may be activated and the X-ray detector 520 may be recording the image generated thereby. Similarly, in FIG. 5C, the third pixel 516B in the x-ray source 510
is activated to produce an x-ray beam 514 that projects onto the detector 520, which records the projected image while the screen 530 and x-ray detector 520 are in the first position. Screen 530 displays second pixel 516A and third pixel 51 in X-ray source array 512.
During activation of 6B, it remains in the first position, so the light pattern produced by light spot 544 remains the same for geometry calibration purposes.

However, in FIG. 5D, screen 530 and X-ray detector 520 are moved to a second position that is different from the first position (shown in dotted lines). In the example shown in FIG. 5D, screen 530 and X-ray detector 520 are moved in the x direction toward the left with respect to X-ray source 510. Screen 530 and x-ray detector 520 may move, but x-ray source 510 remains in its initial position. In such a scenario, when the light beam 542 is projected onto the screen 530, the light spot 544 projects onto the screen 530 at a different location than when the screen 530 was in the first position. The light patterns formed from 544 have different geometries. This still applies for every subsequent position to which the screen 530 and X-ray detector 520 are moved, each subsequent position also being different from the first position and each other.

Therefore, when screen 530 and X-ray detector 520 are moved to the second position, or any position other than the first position, camera 550 detects that X-ray detector 520 and screen 530 are a computing platform (e.g., 804 in FIG. 8) for processing and geometry calibration of the captured second light pattern. can be configured to send to. For example, camera 550 may be configured to capture an image that includes light spots 544 forming a second light pattern on screen 530 when x-ray detector 520 and screen 530 are in the second position. can. Processing of this captured image can be used as a reference for geometry calibration. In some aspects, still referring to FIG. 5D, the fourth pixel 5 in the x-ray source array 512
16C can be activated to generate an x-ray beam 514 that projects onto the detector 520, which is projected while the screen 530 and the x-ray detector 520 are in the second position. Record images. Activation of each successive pixel 516 in the X-ray source array 512 in the second position is also activated to generate another successive image while the X-ray detector 520 and screen 530 are in the second position. It can happen.

In some aspects, 3D image reconstruction can begin after each pixel 516 in the x-ray source array 512 is activated and a projected image is recorded by the x-ray detector 520. For example, 3D image reconstruction can include tomosynthesis reconstruction. 3D image reconstruction can be performed using a computer program and/or workstation (e.g., 804 in FIG.
) can be used to analyze, calibrate, reconstruct, display, etc. 3D tomographic images from recorded 2D projection images. Geometry calibration data (e.g., photographic images) captured and recorded by camera 550 is utilized by a computer program and/or workstation to determine the relative position of each pixel 516 of x-ray source array 512 with respect to x-ray detector 520. can be determined. This position data is used for tomosynthesis reconstruction of the 3D image of the tooth.

6A-6C, each of which shows an example of a captured image resulting from light beam 542 being projected onto plate 530 and producing light spot 544. FIG. Figure 6A
6C illustrate a different position and/or orientation of the screen 530 relative to the light source (eg, 540). In particular, as a result of moving screen 530 relative to the light source, the light pattern produced by light spots 544 on screen 530 can change. Thus, by comparing and analyzing the pattern of 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 diagram, generally indicated at 600A, of a first light pattern, indicated generally at 544A, produced at a first position and a first orientation of the screen 530 relative to the light source. In FIG. 6A, the light spots of the first light pattern 544A form a first light pattern that is located at a "short z distance" relative to the light source and at an x-ray source (e.g.
10) Indicates that it is located in a plane parallel to the plane containing the light source mounted above. Here, "short" is defined for FIG. 6B and "long z distance," ie, a smaller z distance from the x-ray source than when screen 530 is placed along a long z distance. Therefore, as the screen 530 is placed closer to the light source in the z direction, the spaced light spots of the first light pattern 544A become more closely spaced.

FIG. 6B shows a second schematic, generally indicated at 600B, of a second light pattern, indicated generally at 544B, produced with the first orientation of the screen 530 in a second position but still relative to the light source. Show the diagram. In FIG. 6B, the light spots of second light pattern 544B form a second light pattern, which occurs when screen 530 is mounted at a "long z distance" to the light source and above the x-ray source. Indicates that it is placed in a plane parallel to the plane containing the light source. Therefore, when the screen 530 is placed farther from the light source in the z-direction, the second light pattern 54
The light spot of 4B is more spread out.

FIG. 6C shows a third schematic diagram, generally designated 600C, of a third light pattern, generally designated 544C, produced at a third position and second orientation of the screen 530 relative to the light source. show. In FIG. 6C, the light spots of the third light pattern 544C form a second light pattern, which the screen 530 is mounted at a z distance of about 10 cm to 40 cm relative to the light source and above the X-ray source. indicates that the light source is placed in a rotated plane with respect to the plane containing the light source. When the screen 530 is rotated relative to the plane containing the light source, the third light pattern 54
The relative distance between each light spot of 4C may be different if the screen 530 were oriented parallel to the plane containing the light sources. In such cases, rotation calculations 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 sources, the relative distance between each light spot of the third light pattern 544C increases. Conversely, if the screen 530 does not rotate much with respect to the plane containing the light source, the relative distance between each light spot of the third light pattern 544C will be small.

Referring now to FIG. 7, a third embodiment of an exemplary embodiment of a geometry calibration device 700 for use in an intraoral tomosynthesis system (eg, system 100) is schematically illustrated. Geometry calibration device 700 may include, for example, a light source 710, a camera 720, a screen or plate 730, a first grating 740, and a second grating 750.

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

In some aspects, light source 710 can be projected onto a screen or plate 730 through at least one optical grating. Two optical gratings 740 and 7
50 is included within geometry calibration device 700. The screen or plate 730 is
It may 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, screen 730 may be attached to an intraoral x-ray detector and placed outside the patient's mouth. Plate 730 may include, for example, a crossbar (e.g., FIGS.
322, 522 of FIGS. 3B and 5A-5D, respectively) can be used to attach to the X-ray detector at a known relative position. Plate 730 can include paper, plastic, metal or any combination of these materials, and plate 730 has dimensions of approximately 5 cm to 2 cm.
It is 0 cm.

In some aspects, plate 730 can include a predetermined calibrated marker 732 that is centrally located or otherwise positioned. Predetermined calibrated marker 73
2 may include a square or other enclosing shape surrounding an area. The light source 710 is
A split beam of light, indicated generally at 752, may be configured to project onto the plate 730, particularly within the shape formed by the predetermined calibrated markers 732. Using predetermined calibrated markers 732 as reference points for light points M0, M1, M2, etc.
The position of the X-ray detector to which plate 730 is attached relative to the source can be determined, and this is discussed in more detail below. In some aspects, plate 730 includes a calibration circle 734 defined within a predetermined calibrated marker 732. The position of the calibration circle 734 is
It may be predetermined by the operator as corresponding to the desired position of light source 710. Therefore, the operator can determine that the light beam 702 generated by the light source 710 is at the initial light point M0
The position of light source 710 can be adjusted to produce within calibration circle 734.

In some embodiments, at least one diffraction grating may be attached to the x-ray source at a known location. As shown in FIG. 7, two diffraction gratings 740 and 750 are placed in front of the light source 710, so that the light beam emitted from the light source 710 passes through the gratings 740 and 750, which can split the light beam. can be projected through. The split light beam can then be projected onto the plate 730 in the form of multiple light spots M1, M2. In particular, an initial light spot M0 from the light beam is also projected onto plate 730.

In some aspects, gratings 740 and 750 can be 1D or 2D optical gratings with known diffraction line spacing between them. According to the exemplary embodiment of FIG. 7, the first grating 740 is a 1D grating and the second grating 750 is also a 1D grating. In some aspects, diffraction gratings 740 and 750 can each include diffraction line spacings that can be similar or different from each other. Diffraction line spacing can include the distance between each diffraction line in the grating. For example, first grating 740 and/or second grating 750 can be configured with a line spacing that can include lines spaced, for example, about 0.001 mm to 0.1 mm apart. can. In other aspects, the grid 74
0 and 750 may include the same optical dimensions and may be oriented in different directions relative to each other. In FIG. 7, for example, first grating 740 and second grating 750 are rotationally oriented with respect to each other. According to this exemplary embodiment of geometry calibration device 700, first grating 740 is rotated 90 degrees with respect to the orientation of second grating 750.

Gratings 740 and 750 may be configured to split the initial light beam 702 emitted by light source 710 to produce multiple light spots M1, M2 on plate 730. Initial light beam 702 can be a light beam that includes wavelengths in the visible range (eg, about 390 nm to 700 nm). Initial light point M0 may be generated by light beam 702 and may be used as a reference for positioning light source 710 and thus the x-ray source within calibration circle 734.

Light beam 702 can also be configured to pass through one or more diffraction gratings. Because the geometry calibration device 700 has at least one diffraction grating (e.g., first and second gratings 740, 750), the light source 710 is configured such that the light beam 702 is aligned with the diffraction grating 740 and the 750 and can be mounted to pass through the grid 74
0 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, where m=0, 1, 2, 3 are the diffraction points where 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 grating slit separation. As shown in FIG. 7, for example, a light beam 702 passes through a first grating 740 and a second grating 750, each grating rotated 90 degrees with respect to the other. The first diffraction grating 740 is configured with a first diffraction line spacing including, for example, horizontal lines spaced from about 0.001 mm to 0.1 mm, and the second grating 750 is configured with a first diffraction line spacing, e.g.
．． The second diffraction line spacing includes vertical lines spaced from 0.001 mm to 0.1 mm. It will be appreciated that other diffraction line spacings, both vertical and horizontal, are within the skill of those skilled in the art. Thus, the beam 702 is split horizontally by the first grating 740 into a plurality of horizontal beams 742, the central beam of which passes through the second grating 750;
As a result, this central beam of horizontal beams 742 is split into separate vertical beams 752. In some aspects, split horizontal and vertical beams 742 and 752 may be projected onto plate 730 within an area defined by predetermined calibrated markers 732. According to the exemplary embodiment of FIG. 7, eight separate beams, four horizontal beams 742 and four vertical beams 752, are projected onto the plate 730, producing eight separate light spots M1, M2. A 2D light pattern 736 is formed including: 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 light spots M1, 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 with respect to the X-ray detector.

In some aspects, camera 720 captures at least one projected image of light points M1, M2 and initial light point M0 within a predetermined calibration marker 732 and transmits at least one captured image to a computing platform. (See 804 in FIG. 8, for example). For example, camera 720 may be configured to locate an initial light point M0 within calibration marker 732 on plate 730 to determine the translational position of plate 730 relative to the x-ray source, and thereby determine the position of the x-ray detector relative to the x-ray source. and light spots M1, M2
An image capturing the location of can be sent to a computing platform. Therefore, for each intensity peak, when the beam 702 hits the first grating 740 using a light pattern 736 with an initial light point M0, light points M1, M2, a predetermined calibration marker 732, and a diffraction angle θm. The distance between the position of M1, M2 and each light spot M1, M2 on plate 730 can be determined on a computing platform. For example, the geometry calibration module calculates the distance between the position of the beam 702 when it hits the first grating 740 and each light spot M1, M2 on the plate 730, as well as three angles of axial rotation of the plate 730. be able to. In particular, all six degrees of freedom of plate 730 are such that light point M1,
It can be determined from the light pattern 736 formed by M2. 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 plate 730 and the relative position of the x-ray source with respect to light source 710.

Therefore, regardless of the technique used for geometry calibration purposes, the
The angular and/or translational position of the ray detector can be determined, which can help accurately reconstruct tomosynthesis images from the acquired X-ray projection images. Accordingly, the determined position (e.g., angular position and/or translational position) of the X-ray source during image acquisition may enable generating tomosynthesis reconstructed images of the imaged object.

Referring now to FIG. 8, an exemplary embodiment of a fixed intraoral tomosynthesis system 802 interfaces with an exemplary computing platform 804.
A schematic system diagram, generally designated 800, is shown. In particular, when configured as described herein, the example computing platform 804 acquires 2D projection images from multiple viewpoints and then combines such images with movement of the x-ray source or the patient. Processing without accompanying results in a dedicated computing platform that can improve the technical field of fixed intraoral tomosynthesis imaging for 3D dental imaging.

In some aspects, the exemplary tomosynthesis system 802 is similar to that shown in FIG. 1 (e.g., 10
0), including a tomosynthesis system as described above in FIG. 9 and/or FIG. In some aspects, tomosynthesis system 802 is as described above (e.g., 30
0, 500, 700), etc. may be provided. Tomosynthesis system 802 can be configured to interface with a computing platform 804 for calibrating the geometry of system 802 by processing photographic images. For example, the tomosynthesis system 802 can be connected to the computing platform 80 from the intraoral detector via an interface such as a data transmission line, wireless transmission, etc., connecting the intraoral detector to the computing platform.
The projection image may be configured to transmit one or more projection images to the computer. Computing platform 804 may also be configured for tomosynthesis reconstruction of 2D projection images.

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

In some aspects, computing platform 804 is configured to perform one or more aspects related to calibrating the geometry of tomosynthesis system 802, as well as aspects other than geometry calibration, such as tomosynthesis reconstruction. A geometry calibration module 806 may be included. In some aspects, computing platform 804 can also include a separate tomosynthesis reconstruction module (not shown) configured to reconstruct the acquired 2D X-ray projection images. In particular, geometry calibration module 806 can be configured to perform tomosynthesis reconstruction and geometry calibration. 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 tomosynthesis system 802. Geometry calibration module 806 can include functionality 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 may adjust the geometry of the screen from the geometry calibration device 810 for each adjustment in the position of the x-ray detector relative to the ROI of the object to which the screen, plate, etc. , can receive photographic images of various positions of light patterns, light spots, etc. on a plate, etc. In this example, the user of the geometry calibration module (e.g., a device or computing platform available to the user or operator) adjusts the light on the screen, plate, etc. for each adjustment in the position of the x-ray detector relative to the ROI of the object. At least one photographic image of a pattern, light spot, etc. is captured, which may later be received by geometry calibration module 806.

A tomosynthesis reconstruction module, separate from or integrated with the geometry calibration module, may be configured to acquire and/or process 2D X-ray projection images of the object. For example, the tomosynthesis reconstruction module can perform filtered backprojection and iterative reconstruction (e.g., iterative truncation artifact reduction).
Various algorithms may be configured to reconstruct the acquired 2D X-ray projection images of the object, including execution (artifact reduction).

Computing platform 804 and/or geometry calibration module 806 may include functionality to store one or more photographic images for future use. In some aspects, computing platform 804 and/or geometry calibration module 806 may include functionality to instantiate or initialize images and/or provide images to other computing platforms or devices. For example, computing platform 804 and/or geometry calibration module 806 may receive one or more photographic images, calibrate the geometry of system 802 based on those images, and/or transmit those images via interface 808. may be provided to other nodes for geometry calibration of tomosynthesis system 802.

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

In some embodiments, computing platform 804 and/or geometry calibration module 806 may include one or more communication interfaces for interacting with users and/or nodes. For example, computing platform 804 and/or geometry calibration module 806 can provide a communication interface for communicating with users of computing platform 804 and/or geometry calibration module 806. In some aspects,
Computing platform 804 and/or geometry calibration module 8
The user of 06 may be an automated system or may be controlled or controllable by a human user. Computing platform 804 and/or
Alternatively, a user of geometry calibration module 806 may use a camera of device 810 to capture one or more photographic images and send these images to computing platform 804 and/or geometry calibration module 806. . According to the exemplary embodiment of FIG. 8, computing platform 804 includes:
one or more monitors 81 configured to display at least a portion of the reconstructed 3D tomosynthesis image and/or at least a portion of the one or more 2D projection images
4 is shown electrically connected to. One or more monitors 814 may be of any suitable type (eg, CRT, LCD, OLED, holographic, projection, etc.) and arranged in any suitable configuration and number.

In some embodiments, the computing platform 804 is configured to
Functionality may be included to configure the tomosynthesis system 802 described herein to acquire 2D X-ray projection images of the OI. For example, computing platform 804 can control acquisition of 2D X-ray projection images using tomosynthesis system 802 by activating an X-ray source to begin generating an X-ray beam. In another aspect, computing platform 802 can include functionality to change conditions within tomosynthesis system 802, including, for example, moving a translation stage, moving an x-ray detector relative to an object, etc. . In some aspects, the computing platform 804 has the ability to generate content (e.g., 3D tomosynthesis images reconstructed using previously acquired 2D X-ray projection images) and/or storage associated with an imaging session. can include the ability to retrieve the content that has been created.

According to another example embodiment of a fixed intraoral tomosynthesis system, shown generally at 900, the tomosynthesis system 900 shown in FIG. , an X-ray detector holder 910, and a degree of freedom device 940 at one end,
An articulated arm 950 with a control unit 960 at the other end and an X-ray source 93 at one end.
0 and whose other end is magnetically coupled to the X-ray detector holder 910. It is contemplated that x-ray collimator 920 may be coupled to x-ray detector holder 910 by any suitable fasteners.

In some aspects, tomosynthesis system 900 may be mounted so that it is immobile. For example, the tomosynthesis system 900 can be mounted on a ceiling, a wall, or the like. In other aspects, tomosynthesis system 900 may be mobile. For example, tomosynthesis system 900 may include wheels and may be placed on a moving cart, hand truck, stand, etc. Further, control unit 960 can include a power supply, control electronics, cabling, etc. that are at least partially housed within control unit 960. In some aspects, a power source (not shown) may be provided within articulated arm 950 rather than within control unit 960. In some embodiments, the power source can include a rechargeable battery (not shown) that can provide power for imaging, thereby disconnecting electrical cords and/or wires for power during use. remove the need. The articulated arm 950 is, according to some embodiments, attached to a control unit 960 at one end and an X-ray source 930 and/or a detection component (e.g., X-ray detector 912) at another end. can be attached to. In some aspects, cabling is routed along articulated arm 950 from control unit 960 to x-ray source 930 and/or detection components (e.g., x-ray detector 912) to connect these components to 3D Can be used for dental imaging. In other aspects, the cable routing may be inside the articulated arm. In further aspects, the cable routing may be provided separately from the articulated arm or in a manner other than that described above. A degrees of freedom (DOF) device 940 connects articulated arm 950 and
The X-ray source 930 and/or the X-ray detector 912 can be oriented in three degrees of freedom around the imaged object.

Articulated 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 connected to the first At the end of 1 the control unit 96
Attached to 0. For example, the extension arm 952 of FIG. 9 may be pivotable in a first horizontal plane. The second end of the extension arm in this embodiment is connected to the first arm section 954.
The first arm section 954 is attached to the first end of the first arm section 954 via a pivot and/or another type of attachment that allows the first arm section 954 to pivot substantially in a second plane. For example, the first arm section 954 of FIG. 9 may be pivotable in a second vertical plane that is substantially perpendicular to the first horizontal plane. However, the pivoting of the first arm section 954 in the second plane may be limited to about 180 degrees due to the interference of the extension arm 952. Therefore, the first
The second end of the arm section 954 of the arm section 954 includes a pivot and/or another The second arm section 956 is attached to the first end of the second arm section 956 via a type of fitting. For example, the second arm section 956 of FIG. 9 may be pivotable in a 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 connected to the DOF device 940 and/or the DOF device 94.
0 is attached to another suitable type of fixture that allows it to rotate around an axis.
In this manner, the tomosynthesis system 900 performs x, y,
and/or z. Thus, the tomosynthesis system 90
0 can be freely moved and rotated for optimal placement. As a result, the tomosynthesis system 900 can obtain multiple projections of an ROI of an object (e.g., a patient's teeth) without moving either the X-ray source 930, the X-ray detector 912, or the ROI. , it is essentially a fixed type. This is due, at least in part, to the articulated arm 950 with the DOF device 940 or structure attached to one end of the articulated arm 950.

X-ray source 930 and X-ray detector 912 of FIG. 9 may be configured in a similar manner as described above with reference to FIG. In some aspects, the x-ray source 930 has focal points that are linearly or otherwise spatially distributed. In some aspects, 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 control unit 960, and the extraction voltage is set to the same x-ray tube current for each pixel in the x-ray source array. The x-ray exposure level for each of the one or more x-ray projection images configured to be subjected to a pixel extraction gate is set by changing the exposure time. In some aspects, the systems described herein may be operated in a constant exposure mode, such that the x-ray exposure level is adjusted by changing the x-ray tube current for each pixel. It is composed of

In some aspects, 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 exposure from a spatially distributed x-ray source array to may be a digital detector that records images of the X-ray source, each of the one or more images being formed by X-ray radiation emitted from a corresponding focus of a spatially distributed array of X-ray sources.

In some aspects, the x-ray detector 912 shown in FIG. 9 is attached to an x-ray detector holder 910 for bitewing imaging applications. For example, FIG. 10 shows an X-ray detector holder 910
2 provides a more detailed perspective view of an exemplary embodiment of FIG. X-ray detector holder 910 can include biocompatible plastic, although other materials functional for use in 3D dental imaging applications are also contemplated. A first end of the x-ray detector holder, indicated generally at 902, is shown configured to be aligned with one end of the collimator, but any suitable detector may be used. , may be snapped or otherwise fitted to a second end, indicated generally at 904, of the x-ray detector holder 910. For example, the first end 902 of the x-ray detector holder 910 has a substantially rectangular profile with an aperture that matches the substantially rectangular profile of the collimator (see 920 in FIGS. 11A-11B). Has a center.

As used herein, "collimator" refers to an aiming cone (e.g., 9 in FIGS. 11A-11B)
14) and/or one or more x-ray limiting collimator plates. A linkage 908 can couple the x-ray detector holder first end 902 to the x-ray detector holder second end 904. The linkage has a slight bend or curvature to
The second end 904 of the radiation detector holder may be positioned substantially within the aperture center of the substantially rectangular profile of the first end 902 of the X-ray detector holder 910.
A 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 otherwise provided.

In some aspects, the first end 902 of the x-ray detector holder is connected to the x-ray detector holder 91
0 in removable alignment with the collimator. According to this exemplary embodiment, a plurality of magnets 906 are provided around the perimeter of a substantially rectangular profile on the first end 902 of the X-ray detector holder 910. For example, ten magnets 906
embedded in the end 902 of.

11A-11B illustrate that the x-ray detector holder 910 of FIG. 9 is aligned with a second collimator plate 916 at one end of a collimator aiming cone 914, generally designated 920. There is. The second collimator plate 916 in FIGS. 11A-11B is
It has a substantially rectangular profile that corresponds to the substantially rectangular profile on the first end 902 of the x-ray detector holder 910 . A plurality of magnets 922 are provided on the substantially rectangular profile of the second collimator plate 916 and correspond in position to the 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, so that the X-ray detector holder 910 and the second collimator plate 916 are sufficiently close together. When brought into range, the magnets 906 and 922 on each component are attracted to each other and the components are brought into alignment with each other by magnetic force. Advantageously, X
The bond between the line detector holder 910 and the second collimator plate 916 on the aiming cone 914 serves to ensure the alignment of the two components relative to each other, but this is not a permanent attachment. Accordingly, the X-ray detector holder 910 and the second collimator plate 916 are brought out of alignment by applying a tensile or shear force between the two structures and breaking the magnetic coupling between them. be able to.

FIG. 12 provides further views of the aiming cone 914 of the collimator 920. a first collimator plate 928 having x-ray limiting and/or attenuation properties and/or features;
An aiming cone 914 is placed between the exit window 924 of the collimator 920 and an x-ray source 930;
Without any mechanical movement of the X-ray detector 912 or the collimator plates 916, 928, the X-ray radiation is restricted or confined to a substantially common area on the surface of the intraoral detector. In some aspects, a first end of aiming cone 914, indicated generally at 926, is connected to x-ray source 93.
0 or otherwise coupled thereto, while the exit window 92 of the aiming cone 914
4 is proximal to or otherwise coupled to the X-ray detector holder 910. 1st
A collimator plate 928 is located at the first end 926 of the aiming cone 914 and a second collimator plate 916 is located at the exit window 924 of the aiming cone 914 . Both first and second collimator plates 928 and 916, in some embodiments, limit or otherwise attenuate the amount of x-ray radiation emitted from collimator 920 in the direction of x-ray detector holder 910. It can be configured to do so. According to one embodiment, the first collimator plate 928 may be configured to adjust one or more aspects of the x-rays for each focal point, and the second collimator plate 916 may be configured to adjust one or more aspects of the x-rays for each focal point. The x-ray field can be configured to further confine the shape and size of the intraoral x-ray detector to protect the patient. Both the first and second collimator plates 916 can include materials that have high levels of x-ray restriction and/or attenuation properties.

Still referring to FIG. 12, the second collimator plate 916 is aligned with the aiming cone 91
It is possible to have an aperture center or a common aperture with a diameter smaller than the diameter of the four apertures or common apertures. The common aperture is shaped as a rectangle, although other shapes are also contemplated. 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 may be rotatable, changeable, and/or replaceable with plates having a common aperture of a different size and/or shape. The common aperture can be configured to further confine 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 in a sideways orientation on the X-ray detector holder 910, the second collimator plate 916 will similarly
can be oriented in a sideways orientation on aiming cone 914 to match the orientation of 2. In another example scenario, when the X-ray detector 912 is oriented in a portrait orientation on the X-ray detector holder 910, the second collimator plate 916 is also positioned on the aiming cone 914. can be oriented in a vertical orientation.

FIG. 13 further shows a first collimator plate 928. The first collimator plate 928 has one or more holes or apertures 932 configured to align with one or more apertures in the x-ray source, thereby determining, for example, the size of the x-ray field. Limiting the beam intensity and/or beam direction of the x-ray beam from x-ray source 930. Figure 12 and Figure 1
According to an exemplary embodiment of No. 3, the seven apertures 932 are connected to the first collimator plate 928.
Seven apertures (
(not shown). Aiming cone 914 and/or X
A bracket 934 is provided for attachment to the source 930 and includes a first collimator plate 9
28 may be integrated. According to this exemplary embodiment, the first collimator plate 9
28 has four integrally formed brackets 934 for removably attaching plates to one or both of the aiming cone 914 and/or the x-ray source 930.

Accordingly, FIG. 14 depicts an exemplary embodiment of a collimator, designated generally at 920,
Here, aiming cone 914 has a first collimator plate 928 at its first end and a second collimator plate 916 at its second end. Each of the one or more focal points 948, seven in this embodiment, emits an x-ray beam 949 that is conditioned by the first collimator plate 928. The x-ray beam 949 travels through the first collimator plate 928, the aiming cone 914, and the second collimator plate 916 to a sensor located on the x-ray detector 912, which is located on the x-ray detector holder. 910 to be held substantially stationary during use. A second collimator plate 916 directs the x-ray beam to the dimensions of the x-ray detector active area (e.g., x-ray detector 912 where data may be collected).
may be configured to further limit the size and/or shape of the area (area defined within). In this manner, collimator 920 may be configured such that the x-ray radiation from each focal point 948 is collimated to the same x-ray detector 912 within a certain percentage of the active detector area size. For example, collimator 920 may be configured to collimate the x-ray radiation to approximately one percent (1%) of the size of the active detector area. but,
Larger or smaller percentages are also contemplated without departing from the scope of the subject matter herein.

Referring now to FIG. 15, illustrated therein is an exemplary embodiment of a degree of freedom (DOF) structure or apparatus, generally designated 940. DOF device 940 is configured to be attached to x-ray source 930 and articulated arm 950. In some aspects, the DOF device 940
The pivot, pin, screw, spring, and/or x-ray source 930 rotates in three independent degrees of freedom relative to the object being imaged (e.g., one or more teeth in a patient's mouth). It can be attached to the x-ray source 930 via any other mechanism that allows it to do so. For example, first arm 942 can be attached to the side and back of X-ray source 930 via pivotable pins 944 that allow X-ray source 930 to rotate about axes CL3 and CL4, respectively. Can be done. In this example, a second arm 946 is attached to the same side of the x-ray source 930 that the first arm 942 was attached to, curves over the top surface of the x-ray source 930, and is attached to an articulated arm 950. It can be attached to the end. The second arm 946 and first arm 942 of the DOF device 940 are connected to the
Although shown as attached to the x-ray source 930, these attachments
30 can also be achieved with a different pivotable pin 944 that allows rotation about axis CL2. The second arm 946 may alternatively be positioned on the other opposing side of the x-ray source 930. As will be understood by those skilled in the art, the three axes CL2, CL3, and C
Different structural configurations of DOF device 940 that can allow rotation of the device about L4 may also be utilized.

Referring now to FIG. 16, a perspective view of an exemplary embodiment of a linear x-ray source array, designated generally at 935, is shown. Linear x-ray source array 935 can be configured with similar characteristics and functionality as described above with respect to x-ray source array 110 of FIG. 1 (e.g., linear x-ray source array 935 of FIG. (can include one or more x-ray focal points). According to this embodiment, linear x-ray source array 935 has a housing 936 for an x-ray tube (e.g., CNT) and one or more pixels, and further includes one or more x-ray beams. and an x-ray exit window 938 configured to provide an outlet for inherent filtration. In some aspects, the x-ray exit window 938 is configured as a rectangular window to provide an exit for linearly distributed x-ray pixels. However, if the x-ray source array 935 is circular, the x-ray exit window 938 may be correspondingly circular in shape. In all embodiments of x-ray source array 935, its x-ray exit window 938 can have any suitable shape. As a result, it will be apparent to those skilled in the art that the x-ray exit window 938 of the x-ray source array 935 is configured to correspond to the size and/or shape of the x-ray pixel distribution therein.

Therefore, the relative orientation of the x-ray source array to the x-ray detector will affect the scanning direction. Figures 17A-17B illustrate this effect. In FIG. 17A, overall 935
The X-ray source array denoted is schematically shown as a linearly distributed X-ray source array, which is oriented with its longitudinal axis A parallel to the x-direction. Thus, in FIG. 17A, if the object being imaged (eg, tooth 106) is placed a certain distance apart in the y direction, the scan direction is perpendicular to the root-to-coronal z direction. 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. Thus, in FIG. 17B, if the object to be imaged (eg, tooth 106) is placed a certain distance apart in the y direction, the scanning direction is parallel to the root-to-coronal z direction.

A method flow diagram illustrating an intraoral tomosynthesis method for 3D dental imaging using a fixed intraoral tomosynthesis system that includes the creation and display of a synthetic two-dimensional (2D) intraoral image is shown in FIG.

In a first step 1000A, system startup and/or checking is initiated. System start-up and/or checking initiated may be accomplished by a medical professional and/or by a dedicated computing device specifically tied to the fixed intraoral tomosynthesis system and/or method of 3D dental imaging. It may be performed robotically and/or automatically using equipment. The dedicated computing device may be a device such as computing platform 804 shown in FIG. In some aspects, the system start-up and/or checking steps can include starting respective components including x-ray detectors, x-ray arrays, computing platforms, and the like.

In the second step 1000B, the patient may check in. For example, a patient may check in and a file containing patient information may be accessed (e.g., from data storage 812 of computing platform 804 in FIG. 8) and transferred to a fixed intraoral tomosynthesis system. Can be uploaded.

In a 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, the patient may be seated in a reclining seat and an intraoral detector attached to a detector or x-ray detector holder 910 (e.g., FIG. can be placed in the patient's mouth.

In a fourth step 1000D, the position of the detector holder may be adjusted to prepare the detector holder for alignment with the aiming cone. For example, a first end of a detector or x-ray detector holder 910 as shown in FIG.
B) may be prepared for attachment.

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

In a sixth step 1000F, the system may be activated to acquire all projection images for 3D tomosynthesis (eg, activated 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 corresponding foci or pixels of an array of X-ray sources that may be spatially distributed. This may include: In some embodiments, each of the x-ray pixels within the x-ray source array can be individually activated. In some aspects, X-ray exposure and data acquisition are configured to be synchronized according to a preprogrammed imaging protocol. The preprogrammed protocol can include a series of steps performed by a computing platform (e.g., 804 of FIG. 8) and its associated fixed intraoral tomosynthesis system that is programmed prior to the tomosynthesis scanning session. . For example, the protocol includes the steps of: (a) triggering the initiation of data collection of an intraoral detector with X-ray photons emitted from a first focal point, the dwell time being the same as the X-ray exposure time; (b) after the dwell time, switching off the X-ray radiation from the first focal point and transmitting data to a computing platform by the intraoral detector for a fixed readout time; (c) at the end of the fixed readout time, switching on the X-ray radiation from the second focus and starting intraoral detector data acquisition again; and (d) the final X-ray emission from the last focus. repeating the process until a line projection image is recorded. In another example, the protocol includes the steps of: (a) triggering the initiation of intraoral detector data acquisition for each frame with X-ray photons emitted from the corresponding focal point, and presetting a dwell time for each of the frames; (b) transmitting data by the intraoral detector to a computing platform after each x-ray exposure; and (c) resetting the intraoral detector after each x-ray image acquisition of the frame; repeating the process until the last X-ray projection image from the focus of the image is recorded. Other protocols may also be included, as will be understood by those skilled in the art. Additionally, X-ray detectors can be configured and/or
or can be designed.

In a seventh step 1000G, image processing and reconstruction may be performed on a computing platform (eg, 804 in FIG. 8). For example, each of the image slices acquired from each x-ray pixel may be reconstructed into a single tomosynthesis image at computing platform 804. In some aspects, the one or more x-ray projection images acquired during the sixth step are transferred from an intraoral detector (see FIG. 9) to, e.g., an intraoral detector to a computing platform. The data may be transmitted to computing platform 804 via connecting wire data transmission lines, wireless transmissions, and the like.

In an eighth step 1000H, which may be optional, a 2D image may 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 or different than the direction in which the original X-ray projection image or images were collected.

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

In a tenth step 1000J, the reconstructed 3D image and/or the optional two
The D image may be displayed to any medical personnel and/or patient using a display. For example, a user may access data storage 812 on which reconstructed 3D images and/or any 2D images may be stored on computing platform 80 of FIG.
The reconstructed image can be displayed on a display associated with 4. In some embodiments, displaying a sequence of one or more composite X-ray projection images from different projection angles allows a health care provider, such as a dentist, to This may be advantageous as it may allow surfaces to be better visualized. In some aspects, 1
One or more composite X-ray projection images are simultaneously displayed together with one or more 3D tomosynthesis slice images (e.g., 3D images used to reconstruct a 3D tomosynthesis image) for e.g. Disease characterization and diagnostic accuracy can be enhanced.

It will be appreciated that the example method flowchart of FIG. 18 is provided for illustrative purposes only and that different and/or additional steps may be implemented 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 a different order or sequence, or may be omitted altogether.

Although described above with reference to illustrations for dental imaging, the systems, methods, and computer-readable media described above can be used for applications other than dental imaging, and are not limited as such. Accordingly, the subject matter may be embodied in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments described above should be considered in all respects to be illustrative and not restrictive. Although the present subject matter has been described with respect to certain preferred embodiments, other embodiments that will be apparent to those skilled in the art are also within the scope of the present subject matter.

It is understood that various details of the subject matter described herein may be changed without departing from the scope of the subject matter described herein. Furthermore, the above description is intended to be illustrative only and not limiting, as the subject matter herein is defined by the claims.

Claims (7)

A method for three-dimensional (3D) imaging using a fixed intraoral tomosynthesis system, the method comprising:
positioning the spatially distributed X-ray source array of the fixed intraoral tomosynthesis system outside the patient's mouth, the spatially distributed X-ray source array comprising one or more spatially distributed X-ray sources; arranging, including multiple focal points;
placing an x-ray detector inside the mouth of the patient using an x-ray detector holder configured for at least one imaging protocol, the x-ray detector holder a plurality of magnets disposed on a first end of an X-ray detector holder, the first end of the X-ray detector holder being positioned outside the mouth of the patient; step and
providing a first collimator plate at a first end of the collimator and a second collimator plate at a second end of the collimator, wherein the second collimator plate providing a collimator plate selected to be aligned with the x-ray detector holder configured for a protocol;
the spatially distributed array of x-ray sources and the collimator, coupling the second collimator plate onto the second end of the collimator and the first end of the x-ray detector holder; coupling to the X-ray detector holder via the second collimator plate by causing
one or more x-rays of the mouth of the patient from one or more viewing angles by sequentially activating each of the one or more focal points to a preset radiation dose and x-ray energy; Obtaining an X-ray projection image, the one or more X-ray projection images being two-dimensional (2D);
transmitting the one or more X-ray projection images to a computing platform;
reconstructing one or more 3D tomosynthesis images from the one or more X-ray projection images using one or more iterative reconstruction algorithms;
processing the one or more 3D tomosynthesis images and displaying the one or more 3D tomosynthesis images on one or more monitors electrically connected to the computing platform. ,Method. the one or more iterative reconstruction algorithms comprising implementing an iterative truncation artifact reduction method to improve image quality and maximize a field of view for a given size of the x-ray detector; The method according to claim 1. generating one or more composite X-ray projection images from a projection direction that is the same or different from the direction in which at least one of the one or more X-ray projection images was collected; 2. The method of claim 1, wherein the composite X-ray projection image is two-dimensional (2D). 4. The method of claim 3, comprising simultaneously displaying the one or more 3D tomosynthesis images and the one or more synthetic X-ray projection images to improve characterization and diagnosis of dental disease. 2. The method of claim 1, comprising displaying the sequence of one or more X-ray projection images from different projection angles to improve visualization of the proximal interface between one or more teeth. A non-transitory computer-readable medium containing computer-executable instructions for controlling a computer to perform a method for three-dimensional (3D) imaging using a fixed intraoral tomosynthesis system, the method comprising:
positioning the spatially distributed X-ray source array of the fixed intraoral tomosynthesis system outside the patient's mouth, the spatially distributed X-ray source array comprising one or more spatially distributed X-ray sources; arranging, including multiple focal points;
placing an x-ray detector inside the mouth of the patient using an x-ray detector holder configured for at least one imaging protocol, the x-ray detector holder a plurality of magnets disposed on a first end of an X-ray detector holder, the first end of the X-ray detector holder being positioned outside the mouth of the patient; step and
providing a first collimator plate at a first end of the collimator and a second collimator plate at a second end of the collimator, wherein the second collimator plate providing a collimator plate selected to be aligned with the x-ray detector holder configured for a protocol;
the spatially distributed array of x-ray sources and the collimator, coupling the second collimator plate onto the second end of the collimator and the first end of the x-ray detector holder; coupling to the X-ray detector holder via the second collimator plate by causing
one or more X-rays of the mouth of the patient from one or more viewing angles by sequentially activating each of the one or more focal points to a preset radiation dose and X-ray energy. acquiring an X-ray projection image, the one or more X-ray projection images being two-dimensional (2D);
transmitting the one or more X-ray projection images to a computing platform;
reconstructing one or more 3D tomosynthesis images from the one or more X-ray projection images using one or more iterative reconstruction algorithms;
processing the one or more 3D tomosynthesis images and displaying the one or more 3D tomosynthesis images on one or more monitors electrically connected to the computing platform. , a non-transitory computer-readable medium. rotating the spatially distributed x-ray source array about three independent axes defined by degrees of freedom (DOF) devices to which the spatially distributed x-ray source array is mounted; 7. The non-transitory computer-readable medium of claim 6, comprising aligning the spatially distributed x-ray source array with respect to the patient's mouth.

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