Systems and methods utilizing an X-ray imaging system having a hybrid detector

Abstract

The present invention provides a computed tomography (CT) imaging system. The CT imaging system includes a gantry capable of rotating about a rotation axis. The CT imaging system also includes an inspection table configured to move a subject to be imaged into and out of a bore of the gantry. The CT imaging system further includes a radiation source mounted on the gantry and configured to emit an X-ray beam. The CT imaging system even further includes one or more detectors configured to detect the emitted X-ray beam, wherein the one or more detectors include a flat panel detector disposed within the inspection table, wherein the inspection table is configured to move the flat panel detector into and out of the bore. The CT imaging system is configured to generate a two-dimensional image of the subject using the radiation source and the flat panel detector.

Description

Background Art

[0001] The subject matter disclosed herein relates to medical imaging, and in particular to utilizing medical imaging systems having hybrid detectors.

[0002] Non-invasive imaging techniques allow images of a patient's internal structures or features to be obtained without performing an invasive procedure on the patient. Specifically, such non-invasive imaging techniques rely on various physical principles (such as differential transmission of X-rays or emission of gamma radiation through a target volume) to acquire data and construct an image or otherwise represent the observed internal features of the patient.

[0003] Medical imaging systems such as X-ray imaging systems (planar radiography) and computed tomography (CT) imaging systems are two different imaging systems. Typically, both X-ray imaging systems and CT imaging systems are kept in separate rooms with dedicated equipment (e.g., power and control systems, collimators, X-ray sources or tubes, workstations, etc.). Although both X-ray imaging systems and CT imaging systems are used as diagnostic tools, there are key technical differences between them (e.g., with respect to spatial resolution, afterglow or lag, source-to-image receiver distance, etc.). One key technical difference is that one utilizes an X-ray imaging system to acquire two-dimensional (2D) images, while the other utilizes a CT imaging system to acquire three-dimensional imaging volumes. In addition, certain imaging workflows utilizing both types of imaging systems may be both expensive and inconvenient. Summary of the Invention

[0004] The following summarizes certain embodiments commensurate with the scope of the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather, these embodiments are intended only to provide a brief overview of possible forms of the subject matter. Indeed, the subject matter may include a variety of forms that may be similar to or different from the embodiments described below.

[0005] According to a first embodiment, a computed tomography (CT) imaging system is provided. The CT imaging system includes a gantry capable of rotating about a rotation axis. The CT imaging system also includes an inspection table configured to move a subject to be imaged into and out of a bore of the gantry. The CT imaging system further includes a radiation source mounted on the gantry and configured to emit an X-ray beam. The CT imaging system even further includes one or more detectors configured to detect the emitted X-ray beam, wherein the one or more detectors include a flat panel detector disposed within the inspection table, wherein the inspection table is configured to move the flat panel detector into and out of the bore. The CT imaging system is configured to generate a two-dimensional image of the subject using the radiation source and the flat panel detector.

[0006] According to a second embodiment, a method is provided. The method includes acquiring a two-dimensional scout scan image of a subject using a radiation source mounted on a gantry of a computed tomography (CT) imaging system and a flat panel detector disposed within an examination table of the CT imaging system supporting the subject. The method also includes determining, via control circuitry of the CT imaging system, whether the scout scan image is sufficient for diagnosis. The method further includes acquiring an imaging volume of the subject using the radiation source and a detector assembly integrated within the gantry of the CT imaging system when the scout scan image is insufficient for diagnosis.

[0007] According to a third embodiment, an X-ray imaging system is provided. The X-ray imaging system includes a gantry capable of rotating about a rotation axis. The X-ray imaging system also includes an inspection table configured to move a subject to be imaged into and out of a bore of the gantry. The X-ray imaging system further includes a radiation source mounted on the gantry and configured to emit an X-ray beam. The X-ray imaging system even further includes a hybrid detection system configured to detect the emitted X-ray beam. The hybrid detection system includes a flat panel detector disposed within the inspection table, wherein the inspection table is configured to move the flat panel detector into and out of the bore. The hybrid detection system also includes a CT detector assembly integrated within the gantry. The CT imaging system is configured to generate a two-dimensional image of the subject using the radiation source and the flat panel detector, and to generate an imaging volume of the subject using the radiation source and the CT detector assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the present invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout, and in which:

[0009] Figure 1 is a combined pictorial view and block diagram of an embodiment of a computed tomography (CT) imaging system as discussed herein;

[0010] Figure 2 Yes Insert Figure 1 A schematic diagram of an embodiment of a flat panel detector within an examination table of a CT imaging system;

[0011] Figure 3 is a schematic diagram of movement of a patient and / or a flat panel detector within a bore of a gantry;

[0012] Figure 4 is a schematic diagram illustrating the position of a radiation source relative to a flat panel detector during a conventional X-ray imaging scan; and

[0013] Figure 5 is a flow chart of an embodiment of a method for performing an imaging scanning workflow. DETAILED DESCRIPTION

[0014] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints that may vary from implementation to implementation. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but remain a routine task of design, fabrication, and manufacturing for those of ordinary skill having the benefit of this disclosure.

[0015] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to indicate that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that additional elements may be present in addition to the listed elements. Furthermore, any numerical examples in the following discussion are intended to be non-limiting, and thus the appended numerical values, ranges, and percentages are within the scope of the disclosed embodiments.

[0016] Embodiments contemplated by the present invention provide a medical imaging system utilizing a hybrid detector. Specifically, the imaging system can be used for both conventional X-ray imaging (e.g., planar radiography) and CT imaging. For example, a radiation source (e.g., an X-ray tube) can be coupled to a gantry of a CT imaging system and used with different detectors depending on the type of imaging being utilized. One detector can include a CT detector assembly integrated within the gantry, which is used during CT imaging (e.g., to generate a 3D imaging volume). Another detector can include a flat-panel detector disposed within a table of the CT imaging system (e.g., inserted into a slot), which is used during conventional X-ray imaging (e.g., to generate a 2D image). The imaging system's control system can automatically switch between different imaging scan modes (conventional X-ray imaging and CT imaging). In certain imaging workflows, the imaging system can utilize a conventional X-ray imaging scan mode to generate a scout scan. The control system can then determine whether to switch to a CT imaging scan mode to acquire further image data based on whether the scout scan is sufficient for diagnostic purposes. For example, if the scout scan is insufficient for diagnostic purposes, the imaging system can switch to a CT imaging scan mode to acquire CT scan data (e.g., via an axial or helical scan). The imaging system enables different imaging modalities to share components (eg, radiation sources, collimators, power and control systems, workstations, etc.), which provides improved imaging system performance, patient convenience, reduced costs, and space savings.

[0017] Although the following embodiments are discussed with respect to a computed tomography (CT) imaging system, the embodiments may also be utilized with other imaging systems (e.g., PET, CT / PET, SPECT, nuclear CT, etc.). Figure 1 , a CT imaging system 10 is shown by way of example. As described in more detail below, the CT imaging system 10 can be used in a conventional X-ray imaging scan mode (e.g., utilizing a flat panel detector) or a CT imaging scan mode (e.g., utilizing a detector assembly 15). The depicted CT imaging system can be housed within a single room. The CT imaging system includes a gantry 12. The gantry 12 has an X-ray source 14 that, in the CT imaging scan mode, projects an X-ray beam 16 toward a detector assembly 15 (e.g., a CT detector assembly) on the opposite side of the gantry 12. The detector assembly 15 includes a collimator assembly 18, a plurality of detector modules 20, and a data acquisition system (DAS) 32. The plurality of detector modules 20 detect the projected X-rays that pass through a patient 22, and the DAS 32 converts the data into digital signals for subsequent processing. In conventional systems, each detector module 20 generates an analog electrical signal representing the intensity of the incident X-ray beam and, therefore, the intensity of the attenuated beam as it passes through the patient 22. During a CT scan to acquire X-ray projection data, the gantry 12 and components mounted thereon are rotated about a center of rotation 24 to collect attenuation data from multiple viewing angles relative to the imaging volume.

[0018] The imaging system 10 also includes a solid-state detector, such as a digital flat panel detector 33 (e.g., inserted into the examination table 46), for use with the radiation source 14 during conventional X-ray imaging scanning modes (e.g., planar radiography) to acquire image data for generating 2D images. The flat panel detector 33 can be an indirect detector (e.g., utilizing a scintillator to convert X-rays into light) or a direct detector (e.g., utilizing a photoconductor to convert incident X-ray photons into electrical charge). The flat panel detector 33 can be connected via a wired (e.g., tethered) or wireless connection to transmit image data. In some embodiments, a wired connection can be utilized to provide power to the flat panel detector 33. The flat panel detector 33 and the CT detector assembly 15 together form a hybrid detector system 35.

[0019] The rotation of the gantry 12 and the operation of the X-ray source 14 are controlled by a control mechanism 26 of the CT system 10. The control mechanism 26 includes an X-ray controller 28, which provides power and timing signals to the X-ray source 14, and a gantry motor controller 30, which controls the rotational speed and position of the gantry 12. An image reconstructor 34 receives sampled and digitized X-ray data from the DAS 32 and performs high-speed reconstruction. The reconstructed image is applied as input to a computer 36, which stores the image in a mass storage device 38. The computer 36 also receives commands and scanning parameters from an operator via a console 40. An associated display 42 allows the operator to observe the reconstructed image and other data from the computer 36. The computer 36 uses the commands and parameters provided by the operator to provide control signals and information to the DAS 32, the X-ray controller 28, and the gantry motor controller 30. In addition, the computer 36 operates a table motor controller 44, which controls a motorized table 46 (and / or a patient support, such as a cradle) to position the patient 22 relative to the gantry 12. Specifically, the table 46 moves (e.g., extends) portions of the patient 22 on the patient support through the gantry opening or aperture 48. Additionally, the table motor controller 44 can control the movement of the flat panel detector 33 into and out of the aperture 48 (e.g., via a compartment within the table 46 in which the flat panel detector 33 is disposed (see FIG. Figure 2 50). Components of the CT imaging system 10 can be used in both conventional X-ray imaging scan mode and CT imaging scan mode. For example, in either mode, the X-ray source 14, collimator assembly 18, control mechanism 26, computer 36, console 40, display 42, and examination table motor controller 44, among other components. As described in more detail below, the control mechanism can be used to automatically switch between conventional X-ray imaging scan mode and CT imaging scan mode based on certain criteria (e.g., whether a scout scan obtained in conventional X-ray imaging scan mode is sufficient for diagnosis).

[0020] Figure 2 Yes Insert Figure 1 Schematic diagram of the flat panel detector 33 within the inspection table 46 of the CT imaging system 10. The CT imaging system 10 is as shown above. Figure 1 The examination table 46 includes a compartment 50 defined by the examination table 46 that is configured to receive the flat panel detector 33 therein. The compartment 50 is configured to receive flat panel detectors 33 of varying sizes. The compartment 50 is located below a patient support 52 that supports a patient or subject to be imaged. The flat panel detector 33 can be secured within the compartment via one or more fasteners.

[0021] Figure 3is a schematic diagram of the movement of the patient 22 and / or the flat panel detector 33 within the aperture 48 of the gantry 12. The examination table 46 is configured to move the patient 22 into and out of the aperture 48 of the gantry 12 via movement of the patient support 52 (as indicated by arrow 54) (e.g., via the examination table motor controller 44). The examination table 46 is also configured to move the flat panel detector 33 (along with at least a portion of the compartment 50) into and out of the aperture 48 of the gantry 12 (e.g., via the examination table motor controller 44). The examination table 46 is configured to move the flat panel detector 33 (and thereby the patient 22) independently of the patient support 52. In certain embodiments, the compartment 50 may be coupled to a mechanical mechanism (e.g., coupled to a motor) that controls the extension and retraction of the compartment 50, thereby controlling the movement of the flat panel detector 33. In the X-ray imaging scan mode, the flat panel detector 33 is disposed within the aperture 48, as shown in FIG. Figure 3 In the CT imaging scan mode, the flat panel detector 33 is disposed outside the bore 48 and the CT detector 15 is used during imaging.

[0022] like Figure 3 As shown, radiation source 14 (e.g., an X-ray tube) is configured or optimized to emit an X-ray beam 56 at an angle 58 wide enough to cover the entire active area of ​​flat panel detector 33. Angle 58 is wider than angle 60 of an X-ray beam 62 typically used when performing imaging with CT detector 15.

[0023] Figure 4 is a schematic diagram illustrating the position of the radiation source 14 relative to the flat panel detector 33 during a conventional X-ray imaging scan. In a typical conventional X-ray imaging position indicated by arrow 64, the radiation source 14 is located directly above the flat panel detector 33 (e.g., top dead center) when emitting an X-ray beam 65. In some embodiments, during a conventional X-ray imaging scan, the radiation source 14 can be rotated via the gantry to positions 64, 66 that are circumferentially offset from the top dead center position 64 (e.g., relative to the rotation axis 22 of the gantry 14 (see FIG. 2 )). Figure 2 )). In these positions 64, 66, as shown, the radiation receiving surface 68 may be positioned relative to the ground or the inspection table 46 (see Figure 3 In some embodiments, when radiation source 14 is used in a position other than top dead center position 64 (e.g., positions 64, 66), the position of the detector can be angled (manually or automatically) via a mechanism within compartment 50 to angle detector 33 (e.g., surface 68) so that it directly faces radiation source 14.

[0024] Figure 5is a flow chart of an embodiment of a method 70 for performing an imaging scan workflow. One or more steps of the method 70 may be performed by one or more components of the imaging system 10 (e.g., the control mechanism 26, the table motor controller 44, the computer 36, etc.). One or more steps of the method 70 may be performed simultaneously and / or in parallel with the imaging system 10. Figure 5 The method 70 includes performing a registration of the position of the patient 22 relative to the CT imaging system 10 (box 72) before acquiring the two-dimensional scout scan image. Patient registration can be performed using techniques known in the art. In some embodiments, patient registration can be performed using one or more scout scans using the CT detector 15. The scout scan utilizes a radiation dose from the radiation source 14 that is lower than the radiation dose typically used during a CT imaging scan for obtaining diagnostic information. The method 72 also includes performing a scout scan (in conventional X-ray imaging mode) using the flat panel detector 33 in combination with the radiation source 14 (box 74). The radiation source 14 in conventional X-ray imaging mode can be located at a top dead center position above the flat panel detector, or offset circumferentially from the top dead center position, as described above. Figure 4 As described above, a 2D scout scan image is acquired from the scout scan. The scout scan image acquired using the flat panel detector 33 is acquired using a radiation dose that is higher than a scout scan performed in a CT imaging scan but lower than the radiation dose used in a CT imaging scan for diagnostic purposes (in contrast to a scout scan acquired in CT imaging scan mode). Compared to the scout scan image acquired in CT imaging scan mode, the scout scan image acquired using the flat panel detector 33 has a higher spatial resolution and is therefore useful for diagnostic purposes. Method 70 includes determining (e.g., via control circuitry of the imaging system 10) whether the scout scan image acquired in conventional X-ray imaging mode is sufficient for diagnostic purposes (block 76). If the scout scan image acquired in conventional X-ray imaging mode is sufficient for diagnostic purposes, the imaging session ends (block 78). If the scout scan image acquired in conventional X-ray imaging mode is sufficient for diagnostic purposes, the control circuitry switches to CT imaging scan mode (i.e., withdraws the flat panel detector 33 from the aperture 48 of the gantry 12), and method 70 includes performing a CT imaging scan to acquire imaging data, thereby generating an imaging volume (e.g., one or more 3D images) for diagnostic purposes (block 80). CT imaging scans can be axial or helical scans.

[0025] The technical effects of the disclosed embodiments include providing a medical imaging system including a hybrid detection system. The medical imaging system can be used in a conventional X-ray imaging scan mode or a CT imaging scan mode. The hybrid detection system includes a flat panel detector (e.g., for conventional imaging scan mode) that can be moved into and out of a bore of a gantry of the medical imaging system. Additionally, the hybrid detection system includes a CT detector assembly (e.g., for CT imaging scan mode). The medical imaging system enables different imaging modalities to share components (e.g., radiation sources, collimators, power and control systems, workstations, etc.), which provides improved imaging system performance, patient convenience, reduced costs, and space savings.

[0026] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any included methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insignificant differences from the literal language of the claims.

Claims

1. A CT imaging system comprising: a frame capable of rotating about an axis of rotation; an examination table configured to move a subject to be imaged into and out of the bore of the gantry; a radiation source mounted on the gantry and configured to emit an X-ray beam; and one or more detectors configured to detect the emitted x-ray beam, wherein the one or more detectors include a flat panel detector disposed within the examination table, wherein the examination table is configured to move the flat panel detector into and out of the bore; wherein the one or more detectors include a CT detector assembly integrated within the gantry; wherein the CT imaging system is configured to generate a two-dimensional image of the subject using the radiation source and the flat panel detector, The CT imaging system includes a control circuit configured to automatically switch the CT imaging system between a first imaging scan mode utilizing the flat panel detector and a second imaging scan mode utilizing the CT detector assembly. 2 . The CT imaging system of claim 1 , wherein the examination table is configured to move the flat panel detector independently of the subject. 3 . The CT imaging system of claim 1 , wherein the radiation source is configured to emit the X-ray beam at an angular width sufficient to cover an entire active area of ​​the flat panel detector. The CT imaging system according to claim 1 , wherein the examination table is configured to accommodate flat panel detectors of different sizes within the examination table. 5 . The CT imaging system of claim 1 , wherein the flat panel detector is configured to transmit acquired image data to the CT imaging system via a wired connection or a wireless connection. The CT imaging system of claim 1 , wherein the radiation source is configured to emit the X-ray beam from a position directly above the flat panel detector. 7 . The CT imaging system of claim 1 , wherein the radiation source is configured to emit the X-ray beam toward the flat panel detector at different circumferential positions relative to the rotation axis.

8. The CT imaging system of claim 1, wherein the CT imaging system is configured to generate an imaging volume of the subject using the radiation source and the CT detector assembly.

9. The CT imaging system of claim 1, wherein the control circuit is configured to automatically switch from the first imaging scan mode to the second imaging scan mode based on whether a scout scan image acquired in the first imaging scan mode is sufficient for diagnosis. 10 . The CT imaging system of claim 9 , wherein the control circuit is configured to switch from the first imaging scan mode to the second imaging scan mode when the scout scan image is insufficient for diagnosis.

11. A CT imaging method, comprising: Acquiring a two-dimensional scout scan image of the subject using a radiation source mounted on a gantry of a CT imaging system and a flat panel detector disposed within an examination table of the CT imaging system supporting the subject; determining, via control circuitry of the CT imaging system, whether the scout scan image is sufficient for diagnosis; When the scout scan image is insufficient for diagnosis, an imaging volume of the subject is acquired using the radiation source and a detector assembly integrated within the gantry of the CT imaging system. 12 . The CT imaging method of claim 11 , comprising registering a position of the subject relative to the CT imaging system before acquiring the two-dimensional scout scan image.

13. The CT imaging method of claim 11, comprising, before acquiring the two-dimensional scout scan image, moving the subject into the bore of the gantry via the examination table, and moving the flat panel detector via the examination table independently of the movement of the subject. 14 . The CT imaging method of claim 11 , wherein acquiring the two-dimensional scout scan image comprises emitting an X-ray beam from the radiation source from a position directly above the flat panel detector.

15. The CT imaging method according to claim 11, wherein acquiring the two-dimensional scout scan image comprises emitting an X-ray beam from the radiation source toward the flat panel detector at a circumferential position not directly above the flat panel detector relative to a rotation axis of the gantry. 16 . The CT imaging method of claim 11 , wherein acquiring the two-dimensional scout scan image comprises emitting an X-ray beam from the radiation source toward the flat panel detector at an angular width sufficient to cover an entire active area of ​​the flat panel detector.

17. An X-ray imaging system comprising: a frame capable of rotating about an axis of rotation; an examination table configured to move a subject to be imaged into and out of the bore of the gantry; a radiation source mounted on the gantry and configured to emit an X-ray beam; and a hybrid detection system configured to detect the emitted X-ray beam, wherein the hybrid detection system comprises: a flat panel detector disposed within the inspection table, wherein the inspection table is configured to move the flat panel detector into and out of the aperture; and a CT detector assembly integrated within the gantry; wherein the X-ray imaging system is configured to generate a two-dimensional image of the subject using the radiation source and the flat panel detector, and to generate an imaging volume of the subject using the radiation source and the CT detector assembly, The X-ray imaging system includes a control circuit configured to automatically switch the X-ray imaging system between a first imaging scan mode utilizing the flat panel detector and a second imaging scan mode utilizing the CT detector assembly.

18. The X-ray imaging system of claim 17, comprising a control circuit configured to automatically switch the X-ray imaging system between a first imaging scan mode utilizing the flat panel detector and a second imaging scan mode utilizing the CT detector assembly.

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