A modular x-ray imaging system includes an application specific module, a base unit in communication with the application specific module, and a mechanical support configured to support the x-ray application specific module. The base unit and application specific module are configured to communicate by wired and/or wireless communication.

TECHNICAL FIELD

The present disclosure relates to a system design for x-ray imaging equipment including digital radiography, fluoroscopy, tomosynthesis, and computed tomography (CT).

BACKGROUND

X-ray imaging is a key technology for medical diagnostics, surgical guidance, and industrial imaging, which provides operators the ability to non-destructively image the content of objects. Systems are currently fully integrated with all of their components incorporated into their respective systems which include the computer, data acquisition system (DAS), x-ray source, x-ray detectors, high voltage power supply, and cooling. For systems with 3D imaging such as tomosynthesis and computed tomography, the systems also contain a means to move the x-ray source and detectors such as a motor, a gantry of significant stiffness to provide accurate motion, and/or a method of maintaining the connection to the x-ray source and collecting data from the x-ray detectors while under motion such as a slip ring. The integrated system is fundamentally limited in portability due its large size and weight and has high costs for each individual system component (>$100,000 per system and sometimes >$1,000,000 per system).

SUMMARY

An aspect of the present disclosure provides a modular x-ray imaging system that includes an application specific module, a base unit, and a mechanical support. The application specific module includes an imaging ring configured to image a patient; a sensor configured to provide positioning data to enable positioning of the imaging ring relative to the patient; a motor configured to position the imaging ring based on the sensed position; and a controller for controlling an output of the plurality of x-ray sources. The imaging ring includes a plurality of x-ray sources configured to generate and emit a beam including an x-ray spectrum; one or more collimators configured to restrict the span of an x-ray beam; one or more filters configured to selectively attenuate and/or block low-energy rays during x-ray imaging; and one or more x-ray detectors configured to detect x-rays generated by the plurality of x-ray sources. The base unit is in communication with the application specific module. The base unit includes a first power supply having an output voltage greater than 10 kV; a second power supply having an output voltage less than 10 kV configured to turn on and off each individual x-ray source of the plurality of x-ray sources; a processor; and a memory. The memory includes instructions stored thereon which, when executed by the processor, cause the modular x-ray imaging system to position the imaging ring based on the sensor and capture imaging data. The mechanical support is configured to support the imaging ring.

In an aspect of the present disclosure, the base unit may further include a battery. The base unit may be configured to operate solely on battery power with part of the battery being able to be changed during operation to maintain battery power longer than a total capacity of the battery.

In an aspect of the present disclosure, the base unit may be configured to move independently of the rest of the x-ray imaging system.

In another aspect of the present disclosure, the base unit may be configured to be connected to, control, and power multiple application specific modules simultaneously.

In an aspect of the present disclosure, the system may further include a second application specific module configured to provide convertible computed tomography (CT) which can operate vertically, or laterally, and any angle in-between.

In an aspect of the present disclosure, the application specific module may be operated as at least one of a vertical or a horizontal CT.

In an aspect of the present disclosure, when operating laterally, the system may further include an x-ray transparent table configured to support a patient with the x-ray transparent table supported by at least two points each on a different half of the table with an opening for the region of interest for imaging.

In an aspect of the present disclosure, the second application specific module may further include: motorized controls; an imaging ring including a controller, a plurality of x-ray sources, one or more anti-scatter grids, x-ray detectors, and communication electronics; a motorized track configured to move motorized controls and an imaging ring; and a sensor configured to position the imaging ring relative to the patient. The motorized controls may provide mechanical alignment of the ring to the patient;

In another aspect of the present disclosure, the motorized track may be configured to move the second application specific module a distance larger than the desired imaging field of view and less than the length of the full body.

In an aspect of the present disclosure, the motorized track may be configured to be rotated around an axis normal to a surface of contact with the mechanical support in order to change a direction of motion.

In an aspect of the present disclosure, the motorized controls may be further configured to move the imaging ring in the x-y plane of the patient using at least one linear degree of motion and at least one angular degree of freedom.

In another aspect of the present disclosure, the system further may include a dynamic anti-scatter grid or a moving anti-scatter grid with a plurality of x-ray sources to optimally remove scatter from each x-ray source.

In an aspect of the present disclosure, the application specific module may be configured to be adjusted in height and/or rotation relative to the normal of a mounting surface of the application specific module.

In an aspect of the present disclosure, the system may further include at least one wired or wireless connection between the application specific module and the base unit with at least one high voltage connection of greater than 10 kV configured to connect the high voltage power supply to the application specific module; and at least one or more low voltage connections of less than 10 kV configured to connect between the power supply configured for powering the motors, a low voltage power supply, and the processor to the application specific module to provide control of the x-ray sources and communication between the data acquisition system and the sensors controlling the positioning of the application specific module.

An aspect of the present disclosure provides an x-ray source alignment apparatus that includes an imaging ring including a plurality of individually packaged x-ray sources configured to emit a beam including an x-ray spectrum; a second sensor configured to provide positioning data to enable positioning of the imaging ring to the patient; a motorized control configured to provide mechanical alignment of the imaging ring to a patient based on the positioning data; and a motorized track configured to move the motorized controls and the imaging ring based on the positioning data.

In an aspect of the present disclosure, the plurality of individually packaged x-ray sources may include at least one focal spot configured for imaging.

In an aspect of the present disclosure, the plurality of individually packaged x-ray sources may further include a filter configured to reduce an intensity of one or more wavelengths from the x-ray spectrum.

In an aspect of the present disclosure, the plurality of individually packaged x-ray sources may further include a collimator configured to direct the x-ray beam.

In an aspect of the present disclosure, the x-ray source alignment apparatus may include a sensor configured to determine the position of the imaging ring relative to the patient.

In another aspect of the present disclosure, a modular x-ray imaging system includes an application specific module; a base unit in communication with the application specific module and configured to power the application specific module; and a mechanical support. The application specific module includes a vertically positionable imaging ring configured to image a patient; a processor; and a memory. The base unit and application specific module are configured to communicate in at least one of a wired and/or wireless manner. The memory includes instructions stored thereon which, when executed by the processor, cause the modular x-ray imaging system to position the imaging ring and capture imaging data. The mechanical support is configured to support the vertically positionable imaging ring.

Further details and aspects of the present disclosure are described in more detail below with reference to the appended drawings.

DETAILED DESCRIPTION

The present disclosure relates to a method for building x-ray systems including 2D, tomosynthesis, and computed tomography (CT).

FIG.1shows a modular x-ray imaging system10. The modular x-ray imaging system10generally includes a base unit100, an application specific module110, and a mechanical support120for the application specific module110. The base unit100and the application specific module110are in communication via connections130. Some of the connections130may be wired or wireless. In aspects, the modular x-ray imaging system10can be converted between upright (FIG.1) and conventional imaging with a patient laying on a bed (FIG.5).

The mechanical support120is used to support the application specific module110. This mechanical support120can be mounted to the ground or be designed to be temporary for easy transportation to improve portability. The mechanical support120has the capability of adjusting the height of the application specific module110or enabling the application specific module110to be rotated, enabling a vertical system to be converted to a lateral system.

In aspects, the base unit100may include an x-ray source102. The base unit100may include a miniature x-ray source including of a field emitter using sharpened silicon nanowires, a vacuum package, and a target anode. The x-ray source may include a focusing mechanism and/or a metal plate which protects the field emitter array from ions. The x-ray source is programmable (for example, when used in an array). The x-ray source is high-performance due to the nature of the x-ray source (vacuum transistor). The x-ray source is compact (>10× smaller volume than conventional x-ray sources) and is batch manufacturable utilizing conventional silicon manufacturing technology.

In aspects, the modular x-ray imaging system10may include a second application specific module configured for convertible CT which can operate vertically, or laterally, and any angle in-between.

Referring toFIG.2, the base unit100includes a processor150, a display160, a high voltage power supply170, a low voltage power supply180, a motor power supply190, a battery200, and a battery power supply210. In various aspects of the disclosure, the processor150may include any suitable type of computing device, for example, a laptop, a desktop, mobile device, and/or a server. The processor150may include any type of suitable processor such as, without limitation, a digital signal processor, a microprocessor, an ASIC, a graphics processing unit (GPU), a field-programmable gate array (FPGA), or a central processing unit (CPU). The processor150may include memory for executing instructions that cause the system to execute various functions.

The high voltage power supply170may supply a voltage greater than 10 kV. The low voltage power supply180may supply a voltage less than 10 kV. The low voltage power supply180may be configured to turn on and off each individual x-ray source34(e.g., x-ray tube) of a plurality of x-ray sources34(FIG.3). The x-ray source(s)34is configured to emit a beam including an x-ray spectrum. The motor power supply190is configured to power one or more mechanical motors. The base unit100may include a plurality of connections220,230to connect different power supplies and communications to one or more application specific modules based upon low or high voltage requirements. The base unit100may be designed so that it is portable and rugged with a battery200as its temporary power supply and also have a battery power supply210to enable charging from an outlet. This would enable the system to operate entirely on its own power if power is interrupted or in the case of field operations. Part of the battery could be replaceable to enable the system power to be replenished if a power outage exceeds its internal battery capacity.

Connections130between the application specific module(s)110and the base unit100may be provided at different voltages which may need to be separated based upon purpose. One or more high voltage connections (>10 kV)230connects the high voltage power supply170to the application specific module depending on the requirements, and at least one or more low voltage (<10 kV) connections220are connected between the motor power supply190, low voltage power supply180, and processor150to the application specific module110to provide control of the x-ray sources34and communication between the data acquisition system292and the sensors280controlling the positioning of the application specific module110(FIG.3). Wireless communication may be used to communicate some information between the processor150and different parts of the application specific module110to reduce the total number of connections.

Referring toFIG.3the application specific module110is shown. The application specific module can be any subsystem module designed for any x-ray imaging modality such as 2D digital radiography, tomosynthesis (e.g., chest and breast tomosynthesis), or computed tomography. The application specific module110includes components specific to the application (e.g., CT module, tomosynthesis module, and/or digital radiography module). The application specific module110generally includes an imaging ring270, sensors280, and motorized controls260. In aspects, the application specific module110may include a motorized track250to move the motorized controls260and the imaging ring270. The motorized controls260may be further configured to control the movement of the imaging ring270in the x-y plane of the patient using at least one linear degree of motion and/or at least one angular degree of freedom. The application specific module110may be configured to be adjusted in height and/or rotation relative to the normal of a mounting surface of the application specific module110.

The motorized track250may be configured to move the application specific module110a distance larger than the desired imaging field of view and less than the length of the full body of the patient P. The motorized track250may be further configured to be rotated around an axis normal to a surface of contact with the mechanical support120in order to change a direction of motion.

The imaging ring270is configured to capture images. The imaging ring270includes a controller290, a plurality of x-ray sources34, one or more anti-scatter grids16, a data acquisition system292, x-ray detectors36(e.g., photon counting or energy integrating), communication system294, and sensors280for positioning the imaging ring270(FIG.4). The anti-scatter grid16is configured for limiting the amount of scattered radiation reaching the detector, thereby improving the quantity of x-ray images. The one or more anti-scatter grids16may include a dynamic anti-scatter grid or a moving anti-scatter grid with a plurality of x-ray sources to optimally remove scatter from each x-ray source34.

The imaging ring270may further include components associated with the x-ray sources34such as x-ray collimators296and/or x-ray filters298. The communication system294is configured for communication between the application specific module110and the base unit100(FIG.1). The x-ray collimator296is generally placed close to the x-ray source34to restrict the span of the x-ray beam. The x-ray filter298is configured to selectively attenuate, or block, low-energy rays during x-ray imaging.

The motorized controls260are configured to provide motion for imaging and to automatically capture the correct images. The motorized controls260may provide mechanical alignment of the ring to the patient P. The sensors280are configured for sensing position data and for enabling positioning the patient P relative to the imaging ring270.

The controller290is configured for controlling the output x-ray sources34(FIG.4). The controller290may include any type of suitable processor such as, without limitation, a digital signal processor, a microprocessor, an ASIC, a graphics processing unit (GPU), a field-programmable gate array (FPGA), or a central processing unit (CPU). The controller290may include memory for executing instructions that cause the system to execute various functions.

The imaging ring270is moved along the z-axis or the height of the patient P to capture an image with a sufficient field of view through a motorized track250. The motorized track250has a range of motion larger than the desired image field of view but less than the entire length of the body of the patient P. The motorized track250is used when the field of view requirements are larger than the field of view provided by the x-ray detectors36. The motorized controls260can enable a combination of motions to position the imaging ring270in the optimal orientation relative to the patient P. Motorized controls260can handle the motion in the x-y plane through a combination of movements in the x-direction, and one or more angular directions of θ, ψ, and Φ; the axes of motion are shown inFIG.3. The imaging ring270includes a sufficient number of x-ray sources34to meet the power requirements of the desired scan and has a sufficient angular coverage by both the x-ray sources and x-ray detectors36to be considered computed tomography. One or more anti-scatter grids16(FIG.4) are configured to reduce the x-ray scatter. The anti-scatter grid16may be dynamic or movable to adjust based upon which x-ray source is currently operational. Finally, sensors280such as cameras may be used to optimally position the imaging ring relative to the patient P.

This design change is enabled by using “stationary” imaging for 3D imaging where a plurality of x-ray sources34illuminate a detector array composed of x-ray detector elements36larger than the field of view of an individual x-ray source62; an example of a stationary CT layout is shown inFIG.4. This system replaces a single x-ray tube and a detector array is being moved relative to the patient requiring strong mechanical supports to move the components, generally heavier than 1000 kg. The removal of the motion, the multiple components, and the difference in the size and weight of the x-ray source enable the x-ray imaging system to be broken up into smaller components. This design change enables multiple x-ray systems to utilize a common base unit reducing the cost, size, weight, and footprint of the overall combined systems, and enables more portability by only requiring part of the system be transferred at one time. The base unit can be transferred to a location with an already mounted application specific module or, alternatively, a new application specific module can be brought in if additional capability is required.

A computed tomography system can be realized using this system design which has the benefits through the modularity or separation of the individual components and a decrease in the overall weight of the application specific module. The modularity and separation of the individual components enables the system to be transported in separate pieces which can be more easily moved and in a smaller vehicle. The reduction in weight enables a convertible CT which can operate as a vertical oriented CT (FIG.5) or a horizontal oriented CT (FIG.1), scanning at a conventional lateral angle or at angle θ in-between vertical and lateral.

Operation as a vertical CT enables the operator to save on footprint as the room no longer requires the need to support the length of a patient, thus saving on the areal cost for the room and the bed of the CT. While the CT is operating in the conventional lateral configuration, an x-ray transparent table240supports the patient with the table supported by at least two points, each on a different half of the table with an opening for the region of interest of imaging. The table with two points of support is enabled by the fact that the bed does not need to provide the motion of the patient relative to the ring, and can now be portable in form-factor (e.g., folding), supporting more weight and being less costly.

Referring toFIG.6a diagram that illustrates an example of a mobile screening system600is shown. The mobile screening system600may include a truck and a mammography610and/or a computed tomography system620. The mobile screening system600includes more than one imaging modality. The mobile screening solution constitutes a vehicle (e.g., a truck or bus) which includes x-ray imaging equipment, additional equipment, and shielding. The mobile screening system has the benefit of reducing the overall cost of ownership of the system, a key challenge for running mobile medical imaging. Another advantage of the mobile screening system having more than one imaging modality like the one described is: 1) the mobile screening system improves the profitability of the operator by up to 40% by saving on personnel, hardware, and/or maintenance costs; 2) the mobile screening system improves patient convenience by allowing patients to be screened for more than one illness; and 3) the mobile screening system reduces the overall required infrastructure to maintain (one bus vs. the total number of individual buses). The modular x-ray imaging system10may be used as an upright and modular CT system, in accordance with the disclosure. The upright and modular CT system may be used for mobile screening (FIG.6) and/or fixed screening.

A stationary CT system breaks the conventional trade-off between the rotation speed of the x-ray tube and detector pair around the gantry compared to the imaging speed of the patient. This requires that the gantry spins at an increasing rate for a reduced detector size or increased scan rate. Due to the electronic rastering of a stationary CT, the “gantry” rotation is now orders of magnitude faster compared to conventional CT enabling high scan speeds with a small detector to save on cost or higher throughput imaging for the same system specifications.

FIG.7is a diagram of inverse geometry computer tomography for use with the system ofFIG.1. The disclosed technology provides a geometrical layout to fix the fundamental trade-off between detector size and field-of-view is the usage of inverse geometry imaging where multiple x-ray sources illuminate different areas of the desired image onto a smaller detector, and the images are stitched together to form the desired field-of-view. This fundamentally changes the cost-equation to building any x-ray imaging system. For CT systems: the cost of the x-ray source module and detector area should be optimized for a given field-of-view. Inverse geometry x-ray imaging may be used for 2D x-ray imaging or tomosynthesis and computed tomography showing clear benefits such as reduced dose, improved image quality by reducing cone-beam artifacts, and reductions in the necessary detector size for a given field of view thereby reducing detector cost. The reduction in cost and detector area can also be used to offset other increases in costs such as more expensive detectors which are photon energy sensitive or with improved spatial resolution, and for other system geometries such as stationary CT or CT performed without moving parts. The disclosed technology provides the benefit over previous demonstrations of inverse geometry systems that used a single vacuum chamber with multiple x-ray sources integrated together causing the challenges listed above. InFIG.7, an array of x-ray sources illuminates a small detector capturing part of the field of view. The complete field-of-view is formed when all of the x-ray sources have illuminated the detector, and the image is stitched together. The array of x-ray sources and the detector rotate in-sync with each other and an image is taken at every angle, theta.

The disclosed technology provides a solution to implementing inverse geometry effectively by producing high-performing, compact, and inexpensive x-ray sources. High x-ray fluxes and fast on/off times (<about 100 μs) are required for high-performance CT and the main challenge of inverse geometry CT. Tight x-ray source pitch is necessary to minimize the size of the detector as the x-ray images must overlap to get the desired x-ray fluxes in certain regions of the image. Finally, the cost for each source must be inexpensive as to make the cost-optimization between the x-ray source and detector size to be favorable. These properties are addressed in the disclosed technology.

Referring toFIGS.8-10a sub-system x-ray source module800is shown. The sub-system x-ray source module800generally includes multiple individually packaged x-ray sources810with one or more focal spots, one or more filters820, a collimator830and/or an x-ray source alignment apparatus840. Each x-ray source810includes two types of connections: an electrical connection between the emitter and gate of the field emission electron source860with the controller, and an electrical connection between the high voltage power supply850(e.g., a voltage above about 10 k volts) and the anode designed to accelerate the electrons to generate x-ray through Bremsstrahlung. Bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. X-ray sources may have a physical or electronic indicators870to show operators whether or not the x-ray sources need to be replaced. The connection to the anode may also carry the cooling liquid to actively remove the heat generated from electrons colliding with the anode. The individualized x-ray source810(e.g., x-ray tube) and its components are repeated to form an array of x-ray source required for an inverse geometry CT. These individual components are then interconnected through high voltage and cooling interconnects900and a common low voltage connections880(FIG.9). These connections are output of the leak-proof outer case or chassis890(FIG.10) through a common high voltage and cooling out, and through the common low voltage connections.

With further reference toFIGS.9and10the entire sub-system x-ray source module800may be electrically isolated by immersing connections and the x-ray sources in insulating, dielectric fluid. This fluid and all of the sub-components are contained through a leak-proof outer case that has one or more connections to drain and fill the sub-system module with dielectric fluid, provide electrical connections between the x-ray sources, controller and high voltage power supply, and provide insulating dielectric fluid to cool the anode.

FIG.11shows a block diagram of the connections between the sub-system x-ray module800and other sub-systems such as the high voltage source920(voltage >about 10 kilovolts), cooling pump830, and a controller840.

Multiple x-ray source sub-systems800may be located on the same system and connected to one or more high voltage power supplies820, cooling pump830and controller840. By utilizing multiple x-ray source sub-systems800, the speed of motion for the system800can either be eliminated in the case of stationary imaging or reduced for conventional CT which reduces the mechanical engineering requirements for such a system800. The controller840is configured to control each x-ray source810independently. Each x-ray source800has an independent calibration profile which is applied at both the x-ray source and detector image. The calibration ensures that each x-ray source810is outputting the proper dose and detector-side calibration mitigates any fine misalignment between the x-ray source810and detector. The proper dose may be determined using scout x-ray images or using other sensors which provide information necessary to estimate the overall dose. The cumulative x-ray flux emitted by the x-ray source810is dynamic as a function of both position and time. The x-ray flux profile can be adjusted by changing the power of each x-ray source810or the amount of time that each x-ray source810is on.

Certain aspects of the present disclosure may include some, all, or none of the above advantages and/or one or more other advantages readily apparent to those skilled in the art from the drawings, descriptions, and claims included herein. Moreover, while specific advantages have been enumerated above, the various aspects of the present disclosure may include all, some, or none of the enumerated advantages and/or other advantages not specifically enumerated above.

The aspects disclosed herein are examples of the disclosure and may be embodied in various forms. For instance, although certain aspects herein are described as separate aspects, each of the aspects herein may be combined with one or more of the other aspects herein. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed. Like reference numerals may refer to similar or identical elements throughout the description of the figures.

The phrases “in an aspect,” “in aspects,” “in various aspects,” “in some aspects,” or “in other aspects” may each refer to one or more of the same or different example Aspects provided in the present disclosure. A phrase in the form “A or B” means “(A), (B), or (A and B).” A phrase in the form “at least one of A, B, or C” means “(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).”

It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications, and variances. The aspects described with reference to the attached drawing figures are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods, and techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the disclosure.