WO2022069254A1

WO2022069254A1 - Co-registration of intravascular data with angiography-based roadmap image at arbitrary angle, and associated systems, devices, and methods

Info

Publication number: WO2022069254A1
Application number: PCT/EP2021/075581
Authority: WO
Inventors: Yannick Marama KUO; Fergus Merritt
Original assignee: Koninklijke Philips NV; Philips Image Guided Therapy Corp
Current assignee: Koninklijke Philips NV; Philips Image Guided Therapy Corp
Priority date: 2020-09-29
Filing date: 2021-09-17
Publication date: 2022-04-07
Anticipated expiration: 2023-03-29

Abstract

A co-registration system includes a processor circuit in communication with a display, an x-ray fluoroscopy imaging device, and an intravascular catheter/guidewire. The processor circuit receives, from the x-ray fluoroscopy imaging device, x-ray fluoroscopy images of a blood vessel while the intravascular catheter/guidewire moves through the blood vessel. The x-ray fluoroscopy images comprise a view of the blood vessel at a first angle. The processor circuit receives, from the intravascular catheter/guidewire, intravascular data representative of the blood vessel while the intravascular catheter or guidewire moves through the blood vessel. The processor circuit generates a roadmap image of the blood vessel based on x-ray angiography data. The roadmap image comprises a view of the blood vessel at a different, second angle. The processor circuit co-registers the intravascular data to the roadmap image. The processor circuit outputs, to the display, the roadmap image and a visual representation of the intravascular data overlaid thereon.

Description

CO-REGISTRATION OF INTRAVASCULAR DATA WITH ANGIOGRAPHY-BASED ROADMAP IMAGE AT ARBITRARY ANGLE, AND ASSOCIATED SYSTEMS, DEVICES, AND METHODS

TECHNICAL FIELD

[0001] The present disclosure relates generally to co-registering intravascular data with angiography-based roadmap images. In particular, intravascular data may be co-registered with a angiographic roadmap image obtained at a different angle than fluoroscopic images of an intravascular device movement through the vessel.

BACKGROUND

[0002] Physicians use many different medical diagnostic systems and tools to monitor a patient’s health and diagnose medical conditions. Different modalities of medical diagnostic systems provide physicians with different images, models, or data of internal structures within a patient. These modalities include invasive systems, such as intravascular systems, and non- invasive systems, such as x-ray systems. Using multiple diagnostic systems to examine a patient’s anatomy provides a physician with added insight into the condition of the patient.

[0003] In the field of intravascular imaging and physiology measurement, co-registration of data from invasive devices with images from non-invasive devices is a powerful technique for improving the efficiency and accuracy of vascular catheterization procedures. Co-registration identifies the locations of intravascular data measurements along a blood vessel by mapping the data to an angiography image of the vessel. A physician may then know exactly where in the vessel a measurement was made, rather than estimate the location. Currently, in order to perform co-registration of intravascular data with an x-ray angiography image, an intravascular pullback must be performed under a fluoroscopy image stream with the x-ray device positioned at some angle. An angiography image must also be obtained with the x-ray device positioned at the same angle.

[0004] Currently, there is no commercially available method of co-registering intravascular data with an angiography image if the angiography image is not obtained at the same angle as the fluoroscopy images obtained during the pullback procedure. If a physician does obtain an angiography image at the same angle as the fluoroscopy images, there is also currently no method of viewing intravascular data co-registered with a view of a patient’s vasculature from any desired angle. The physician is limited to the angle of the obtained angiography image.

SUMMARY

[0005] Embodiments of the present disclosure are systems, devices, and methods for coregistering intravascular data with an x-ray angiography-based image, without requiring that angiography images of the vessel are obtained at the same angle as fluoroscopy images of the intravascular catheter or guidewire’s movement through the vessel to obtain the intravascular data. This advantageously provides a physician with co-registered data in a broader set of circumstances including ones in which no angiography image was obtained at the same angle a the fluoroscopy images. Embodiments of the present disclosure also allow a physician to view a patient’s anatomy with co-registered intravascular data from any desired angle. A system configured to perform the co-registration may include an intravascular device and an x-ray imaging device in communication with a co-registration system.

[0006] The co-registration system receives fluoroscopy images while a pullback is performed with an intravascular device. The co-registration system also receives two or more x-ray angiography images of the patient’s vasculature obtained at two different angles. The x-ray angiography images are used to create a three-dimensional model of the vasculature using two- dimensional projection to three-dimensional matrix transformation techniques. The intravascular data obtained during the device pullback procedure are co-registered to the three-dimensional model. The co-registration system then projects the three-dimensional model to a two- dimensional plane to generate a two-dimensional roadmap image of the patient vasculature with the intravascular data. The two-dimensional roadmap image may depict a view of the patient’s anatomy from any angle, including the angle at which the fluoroscopy images were obtained. The two-dimensional roadmap image is then displayed to a user with the co-registered intravascular data.

[0007] In an exemplary aspect of the present disclosure, a co-registration system is provided. The co-registration system includes a processor circuit configured for communication with a display, an x-ray fluoroscopy imaging device, and an intravascular catheter or guidewire, wherein the processor circuit is configured to: receive, from the x-ray fluoroscopy imaging device, a plurality of x-ray fluoroscopy images of a blood vessel while the intravascular catheter or guidewire moves through the blood vessel, wherein the plurality of x-ray fluoroscopy images comprise a view of the blood vessel at a first angle; receive, from the intravascular catheter or guidewire, intravascular data representative of the blood vessel while the intravascular catheter or guidewire moves through the blood vessel; generate a roadmap image of the blood vessel based on x-ray angiography data, wherein the roadmap image comprises a view of the blood vessel at a second angle different than the first angle; co-register the intravascular data to the roadmap image; and output, to the display, the roadmap image and a visual representation of the intravascular data overlaid on the roadmap image.

[0008] In some aspects, the processor circuit is configured to: receive the x-ray angiography data from an x-ray angiography device in communication with the processor circuit, wherein the x-ray angiography data comprises a first x-ray angiography image of the blood vessel and the second x-ray angiography image of the blood vessel, wherein the first x-ray angiography image and the second x-ray angiography image are obtained at different angles; generate a three- dimensional (3D) model of the vessel based on the x-ray angiography data; and co-register the intravascular data to the 3D model of the vessel based on the plurality of x-ray fluoroscopy images. In some aspects, the first angle is different than the angles at which the first x-ray angiography image and the second x-ray angiography image are obtained. In some aspects, the plurality of x-ray fluoroscopy images comprise two-dimensional (2D) images, and the processor circuit is configured to use a matrix transformation to project locations of the intravascular data from the 2D images to the 3D model to co-register the intravascular data to the 3D model. In some aspects, the processor circuit is configured to use an angle at which the plurality of x-ray fluoroscopy images were obtained to project the locations of the intravascular data from the 2D images to the 3D model with the matrix transformation. In some aspects, the processor circuit is configured to use a matrix transformation to project the 3D model to a 2D plane oriented at the second angle to generate the roadmap image. In some aspects, the roadmap image is a computergenerated representation of the vessel. In some aspects, the roadmap image is a 2D image. In some aspects, the processor circuit is configured to use the matrix transformation to project locations of the intravascular data in the 3D model to the 2D plane to co-register the intravascular data to the roadmap image. In some aspects, the processor circuit is configured to output, to the display, the 3D model and the visual representation of the intravascular data overlaid on the 3D model. In some aspects, the system further includes the x-ray angiography device. In some aspects, the processor circuit is configured to output, to the display, a visualization of the intravascular data corresponding to a location of the visual representation along the blood vessel in the roadmap. In some aspects, the intravascular data comprises at least one of pressure data, flow data, or imaging data. In some aspects, the system further comprises the intravascular catheter or guidewire. In some aspects, the system further comprises the x-ray fluoroscopy device.

[0009] In an exemplary aspect of the present disclosure, a co-registration method is provided. The co-registration method includes receiving, at a processor circuit in communication with an x-ray fluoroscopy imaging device, a plurality of x-ray fluoroscopy images of a blood vessel while an intravascular catheter or guidewire moves through the blood vessel, wherein the plurality of x-ray fluoroscopy images comprise a view of the blood vessel at a first angle; receiving, at the processor circuit, intravascular data representative of the blood vessel from the intravascular catheter or guidewire while the intravascular catheter or guidewire moves through the blood vessel; generating, with the processor circuit, a roadmap image of the blood vessel based on x-ray angiography data, wherein the roadmap image comprises a view of the blood vessel at a second angle different than the first angle; co-registering, with the processor circuit, the intravascular data to the roadmap image; and outputting, to a display in communication with the processor circuit, the roadmap image and a visual representation of the intravascular data overlaid on the roadmap image.

[0010] Additional aspects, features, and advantages of the present disclosure will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Illustrative embodiments of the present disclosure will be described with reference to the accompanying drawings, of which:

[0012] Fig. 1 is a schematic diagram of a medical diagnostic system, according to aspects of the present disclosure.

[0013] Fig. 2 is a diagrammatic view of an intravascular device, according to aspects of the present disclosure.

[0014] Fig. 3 is a diagrammatic view of an x-ray imaging device, according to aspects of the present disclosure.

[0015] Fig. 4 is a schematic diagram of a processor circuit, according to aspects of the present disclosure.

[0016] Fig. 5 is a flow diagram of a method of co-registering intravascular data with an angiography-based image, according to aspects of the present disclosure.

[0017] Fig. 6A is a diagrammatic view of an x-ray angiography image of vessels of a heart, according to aspects of the present disclosure.

[0018] Fig. 6B is a diagrammatic view of an x-ray angiography image of the vessels of the heart shown in Fig. 8 A imaged from a different angle, according to aspects of the present disclosure.

[0019] Fig. 7 is a diagrammatic view of an x-ray angiography-based 3D model of the vessels of the heart shown in Figs. 6A and 6B, according to aspects of the present disclosure.

[0020] Fig. 8 is a diagrammatic view of a relationship between x-ray fluoroscopy images, intravascular data, a path defined by the motion of an intravascular device, an x-ray angiography - based 3D model, and a roadmap image based on the angiography-based model, according to aspects of the present disclosure.

[0021] Fig. 9 is a diagrammatic view of a graphical user interface displaying intravascular data co-registered to an angiography-based roadmap image, according to aspects of the present disclosure.

[0022] Fig. 10 is a diagrammatic view of a graphical user interface displaying intravascular data co-registered to an angiography-based roadmap image, according to aspects of the present disclosure. DETAILED DESCRIPTION

[0023] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It is nevertheless understood that no limitation to the scope of the disclosure is intended. Any alterations and further modifications to the described devices, systems, and methods, and any further application of the principles of the present disclosure are fully contemplated and included within the present disclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately.

[0024] Fig. 1 is a schematic diagram of a medical diagnostic system 100, according to aspects of the present disclosure. The diagnostic system 100 may include an intravascular device 146 in communication with an intravascular data processing system 144, an x-ray angiography imaging device 156 in communication with an x-ray angiography processing system 154, and an x-ray fluoroscopy imaging device 166 in communication with an x-ray fluoroscopy processing system 164. In addition, the diagnostic system 100 may include a co-registration processing system 134 in communication with the intravascular data processing system 144, the x-ray angiography processing system 154, and the x-ray fluoroscopy processing system 164. The coregistration processing system 134 may additionally be in communication with a display 132 as well as any other suitable components, processors, systems, or devices. The diagnostic system 100 may be used for many different medical procedures, such as but not limited to diagnostic procedures, planning treatment, guiding treatment (e.g., during deployment of a treatment device), and evaluating the efficacy of treatment after it has been performed.

[0025] The co-registration processing system 134 shown in Fig. 1 may include any suitable hardware components, software components, or combinations of hardware and software components. For example, the processing system 134 may include any suitable circuitry, communication interfaces, processors, or processor circuits, among other components. In some embodiments, the processing system 134 may include one or more processor circuits substantially similar to the processor circuit 410 described with reference to Fig. 4. Any of the systems 144, 154, and/or 164 may also include one or more processor circuits substantially similar to the processor circuit 410 described with reference to Fig. 4. Any of the systems 144, 154, and/or 164 may also include the same or similar features, components, hardware components, software components, or combinations thereof as those listed with reference to the co-registration processing system 134 described.

[0026] The intravascular data processing system 144 may be configured to receive intravascular data collected with the intravascular device 146. The intravascular data processing system 144 may receive intravascular data via a connecting cable and/or a communication interface as will be discussed in more detail with reference to Fig. 2. In some embodiments, the processing system 144 may process the received intravascular data to reconstruct an image of the tissue structures in the medium surrounding the intravascular device 146. In other embodiments, the system 144 may process received intravascular data to calculate metrics relating to the medium surrounding the device 146 such as, but not limited to, the diameter of a body lumen, fluid pressure or flow within a body lumen, or other physiological data or metrics. The system 144 may also perform any other suitable calculations or measurements depending on the type of device 146 and the type of data received. The intravascular data processing system 144 may be in communication with the display 132 or another display. The intravascular data processing system 144 may display images, visual representations (e.g., numerical/alphanumerical, graphical, symbolic, etc.), metrics, or other data relating to the body lumen imaged or measured via this display.

[0027] The x-ray angiography processing system 154 may be configured to receive angiography data collected with the x-ray angiography imaging device 156. The x-ray angiography processing system 154 may receive x-ray angiography data via a connecting cable and/or a communication interface. The angiography data can be used to generate angiographic images frames depicting the patient’s anatomy. The angiography data obtained with the x-ray angiography imaging device 156 may correspond to an anatomy with a contrast agent introduced. The contrast agent may be used to enhance the visibility of internal fluids or structures within a patient’s anatomy. In some embodiments, the contrast agent absorbs external x-rays from an x-ray source, resulting in decreased exposure on an x-ray detector in conjunction with the x-ray source. The contrast agent may be of any suitable material, chemical, or compound and may be a liquid, powder, paste, tablet, or of any other suitable form. For example, the contrast agent may include iodine-based compounds, barium sulfate compounds, gadolinium- based compounds, or any other suitable compounds. The contrast agent may additionally be referred to as a radiocontrast agent, a contrast dye, a radiocontrast dye, a contrast material, a radiocontrast material, a contrast media, or a radiocontrast media, among other terms.

[0028] In some embodiments, the processing system 154 may process the received angiography data to reconstruct an image of the patient anatomy and/or calculate metrics relating to the anatomy based on the angiography data. In some applications, the x-ray angiography processing system 154 may determine metrics associated with the patient anatomy using various image processing techniques or machine learning techniques. The x-ray angiography processing system 154 may be in communication with the display 132 or another display. The x-ray angiography processing system 154 may display images, visual representations (e.g., numerical/alphanumerical, graphical, symbolic, etc.), metrics, or data to a user of the imaging system 100 via this display.

[0029] The x-ray fluoroscopy processing system 164 may be configured to receive fluoroscopy data collected with the x-ray fluoroscopy imaging device 166. In some embodiments, the x-ray fluoroscopy processing system 164 may be the same system as the x-ray angiography system 154 and the x-ray fluoroscopy imaging device 166 may be the same device as the x-ray angiography imaging device 164. However, the fluoroscopy imaging device 166 may obtain x-ray images of an anatomy without a contrast agent introduced to a patient’s vasculature. In other embodiments, the x-ray fluoroscopy processing system 164 and the x-ray angiography processing system 154 are separate systems and the x-ray fluoroscopy imaging device 166 and the x-ray angiography imaging device 156 are separate devices. In either embodiment, the x-ray fluoroscopy processing system 164 may include any or all of the same features or characteristics of the x-ray angiography processing system 154 and the x-ray fluoroscopy imaging device 166 may include any or all of the same features or characteristics of the x-ray angiography imaging device 156. The fluoroscopy data can be used to generate fluoroscopic images frame depicting the patient’s anatomy. In some instances, the fluoroscopic image frames can collectively form a video sequence of x-ray images.

[0030] In some embodiments, the systems 134, 144, 154, and/or 164 may each be a part of a combined system 100. For example, in some embodiments, the processing systems 134, 144, 154, and/or 164 may all be positioned within the same enclosure or housing. In addition, the processing systems 134, 144, 154, and/or 164 may share one or more software or hardware components. In other embodiments, the processing systems 134, 144, 154, and/or 164 may be separate systems but may be in communication with one another. The processing systems may be in continuous communication with one another or may be in intermittent communication with one another. The processing systems may be in communication with one another or with the devices 145, 156, 166, 176, and/or the display 132 via one or more wired connecting cables including any suitable conductors, such as single conductors, twisted pairs, universal serial bus (USB) cables, or any other suitable connecting cables. The processing systems 134, 144, 154, and/or 164 may additionally or alternatively be in communication or with the devices 145, 156, 166, 176, and/or the display 132 via a wireless connection, an optical connection, or may be in connection via any suitable type of movable memory or storage media, or via any other suitable means of communication. In some embodiments, the co-registration processing system 134 may receive data, including raw data and/or processed data, images, models, visual representations (e.g., numerical/alphanumerical, graphical, symbolic, etc.), metrics, or any other information from any of the processing systems 144, 154, and/or 164. The co-registration processing system 134 may receive such data from the other processing systems 144, 154, and/or 164 simultaneously or separately. Any and/or all of the processing systems 134, 144, 154, and/or 164 may include or be a part of any suitable system or device such as, but not limited to, a mobile console, a desktop computer, laptop computer, tablet, smartphone, or any other suitable computing device.

[0031] Fig. 2 is a diagrammatic view of an intravascular device 146, according to aspects of the present disclosure. The intravascular device 146 may be any type of invasive intravascular device used to acquire data from within the body of a patient. For example, the intravascular device 146 could be a catheter, a guide wire, or a guide catheter. In general, the device 146 can be an intraluminal device that obtains data from within any suitable lumen, chamber, or anatomy within the patient’s body. An intraluminal device can also be referred to as an intra-body probe or an endo-cavity probe. The device 146 can be a sensing device that obtains information about the patient’s body while positioned inside the patient’s body. In some instances, the device 146 is an imaging device, such as an intravascular ultrasound (IVUS) device, including a rotational IVUS device or a solid-state IVUS device, an optical coherence tomography (OCT) device, an intravascular photoacoustic (IVPA) device, an intracardiac echocardiography device, or a transesophageal echocardiography (TEE) device. In some instances, the device 146 is a physiological-sensing device, such as a pressure-sensing device, a flow-sensing device, or a temperature-sensing device. The device 146 may include a flexible elongate member 221, a sensor assembly 210, a sensor 224, a transmission line bundle or cable 212, and a patient interface module (PIM) connector 214, among other components.

[0032] At a high level, the intravascular device 146 may acquire data relating to the region of anatomy surrounding the intravascular device 146. In that regard, the device 146 can be sized, shaped, or otherwise configured to be positioned within the body lumen 220 of a patient. In some embodiments, the system 100 may include a patient interface module (PIM) communicatively disposed between the intravascular device 146 and the intravascular data processing system 144 that receives and transfers the data obtained by the sensor 224 to the intravascular data processing system 144. The intravascular data processing system 144 can execute computer readable instructions stored on a non-transitory tangible computer readable medium.

[0033] The flexible elongate member 221 may be sized and shaped, structurally arranged, and/or otherwise configured to be positioned within a body lumen 220 of a patient. The flexible elongate member 221 may be a part of guidewire and/or a catheter (e.g. an inner member and/or an outer member). The flexible elongate member 221 may be constructed of any suitable flexible material. For example, the flexible elongate member 221 may be constructed of a polymer material including polyethylene, polypropylene, polystyrene, or other suitable materials that offer flexibility, resistance to corrosion, and lack of conductivity. In some embodiments, the flexible elongate member 221 may define a lumen for other components to pass through. The flexible elongate member 221 may be sufficiently flexible to successfully maneuver various turns or geometries within the vasculature of a patient. The flexible elongate member 221 may be of any suitable length or shape and may have any suitable characteristics or properties.

[0034] The sensor assembly 210 may be coupled to the flexible elongate member 221 and positioned at a distal portion or a distal end of the flexible elongate member 221. The sensor assembly 210 may house various circuitry, sensors, transducers, or any other suitable components used to acquire intravascular data. For example, the sensor assembly may include a support member, unibody, sensor housing, sensor mount, pressure sensor, flow sensor, temperature sensor, transducer array, control logic dies, various circuits, flexible substrates, various adhesives, or backing material, among other components. The sensor assembly 210 may provide structural support to components within the intravascular imaging device 146. The sensor assembly 210 may be constructed of any suitable material, including flexible or inflexible materials. The sensor assembly 210 may be of any suitable shape, including a tubular or circular shape, as well as any other geometric or non-geometric shape.

[0035] The sensor assembly 210 can acquire data relating to the lumen in which the device 146 is positioned. The sensor assembly 210 may acquire this data via any suitable number or type of sensors or other measurement tools. The data obtained by the intravascular device 146 and/or the sensor 224 data may be of any suitable form. In some embodiments, the sensor 224 is an ultrasound transducer or ultrasound transducer array. The sensor 224 can include one or more ultrasound transducer elements that emit ultrasonic energy and receive echoes that can be used to generate an ultrasound image (e.g., an IVUS image). In another embodiment, the sensor 224 is a pressure sensor that acquires pressure data at one or more locations along the body lumen of the patient as the device 146 moves through the body lumen. Pressure data can be used by the processing system 144 to calculate fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), Pd/Pa, and/or any other suitable pressure ratio. In another embodiment, the sensor 224 is a flow sensor that obtains data related to velocity and/or volume of blood flow within a blood vessel. Flow data can be used by the processing system 144 to calculate coronary flow reserve (CFR), and/or any other suitable flow metric. For example, the flow sensor 224 can be a Doppler ultrasound transducer element. In another embodiment, the sensor 224 is a temperature sensor that obtains temperature data within the body lumen. In other embodiments, the sensor 224 may acquire OCT imaging data, IVPA imaging data, or any other suitable data.

[0036] The sensor 224 shown in Fig. 2 may be any suitable type of sensor depending on the specific application or type of intravascular device 146 including any of the components for intravascular data acquisition previously listed. In addition, the sensor 224 may represent more than one sensor. For example, in some embodiments, the sensor 224 may include multiple sensor devices including 2, 4, 6, 8, 16, 32, 64, 128, or more sensors, or any suitable number therebetween. In some embodiments, the sensor 224 may include a transducer array. The sensor 224 may additionally be a single rotating transducer. In some embodiments, the sensor 224 may be one or more pressure sensors and one or more flow sensors. The sensor 224, although positioned at a distal region of the sensor assembly 210 and the flexible elongate member 221, may be positioned at any suitable location on or within the sensor assembly 210 or the flexible elongate member 221.

[0037] The flexible elongate member 221 and/or the cable 212 include one, two, three, four, five, six, seven, or more conductors, optical fibers, or other signal communication lines. The signal communication lines are communicatively coupled to the connector 214 and the sensor 224. The signal communication lines carry electrical signals, optical signals, and/or any suitable type of signal from the sensor 224 to the processing system 144 (e.g., data obtained by the sensor 224) and/or from the processing system 114 to the sensor 224 (e.g., command/control signals). The cable 212 may facilitate communication between the intravascular device 146 and the intravascular data processing system 144 or any other control system or host system.

[0038] The cable 212 may be coupled to the patient interface module (PIM) connector 214 at a proximal portion or proximal end of the intravascular device 146. The PIM connector 214 may communicatively couple the signal communication lines to the PIM or other interface in communication with the intravascular data processing system 144. The PIM connector 214 may also physically couple the intravascular device 146 to the PIM.

[0039] In some embodiments, the intravascular device 146 and/or the PIM may perform preliminary processing of the intravascular data prior to relaying the data to the processing system. In examples of such embodiments, the intravascular device 146 and/or the PIM may perform amplification, filtering, and/or aggregating of the data. In an embodiment, the intravascular data processing system 144 and/or the PIM may also supply high- and low- voltage DC power to support operation of the device 146 including circuitry within the device.

[0040] Fig. 3 is a diagrammatic view of an x-ray imaging device, according to aspects of the present disclosure. The x-ray imaging device 300 may be the x-ray angiography imaging device 156 (Fig. 1) or may be the x-ray fluoroscopy imaging device 166 (Fig. 1) or may be a different device. In some embodiments, the x-ray imaging device 300 shown in Fig. 3, the x-ray angiography imaging device 156, and the x-ray fluoroscopy imaging device 166 may be the same device. The x-ray imaging device 300 may be of any suitable type, for example, it may be a stationary x-ray system such as a fixed c-arm x-ray device, a straight arm x-ray device, or a u- arm device. The x-ray imaging device 300 may additionally be any suitable mobile device such as a mobile c-arm x-ray device. The x-ray imaging device 300 may also be in communication with the x-ray angiography imaging processing system 154 and/or the x-ray fluoroscopy processing system 164. In some embodiments, the x-ray device 300 may include a digital radiography device or any other suitable device.

[0041] The x-ray imaging device 300 as shown in Fig. 3 includes an x-ray source 360, a detector 370 including an x-ray input screen 374. The x-ray source 360 and the input screen 374 may be mounted at a mutual distance and mounted on a movable arm 352. Positioned between the x-ray source 360 and the x-ray detector 370 may be an anatomy of a patient or object 380. The x-ray imaging device 300 may be used to image any suitable location or region of a patient’s anatomy, including tissues, organs, malignancies, or any other structures or features. For example, the x-ray imaging device 300 may image without limitation the liver, heart, kidneys, gall bladder, pancreas, lungs; ducts; intestines; nervous system structures including the brain, dural sac, spinal cord and peripheral nerves; the urinary tract; as well as valves within the blood vessels, blood, chambers or other parts of the heart, abdominal organs, and/or other systems of the body. The imaging device 300 may additionally image tumors, cysts, lesions, hemorrhages, or blood pools, muscle, blood, blood plasma, interstitial fluid, lymph plasma, cerebrospinal fluid, intraocular fluid, serous fluid, synovial fluid, digestive fluid, urinary fluid, amniotic fluid, or any other type of suitable fluid, or any other region, structure, fluid, or gas within a patient anatomy. [0042] The x-ray source 360 may include an x-ray tube adapted to generate x-rays. Some aspects of the x-ray source 360 may include one or more vacuum tubes including a cathode in connection with the negative lead of a high-voltage power source and an anode in connection with the positive lead of the same power source. The cathode of the x-ray source 360 may additionally include a filament. The filament may be of any suitable type or constructed of any suitable material, including tungsten or rhenium tungsten, and may be positioned within a recessed region of the cathode. One function of the cathode may be to expel electrons from the high voltage power source and focus them into a well-defined beam aimed at the anode. The anode may also be constructed of any suitable material and may be configured to create x- radiation from the emitted electrons of the cathode. In addition, the anode may dissipate heat created in the process of generating x-radiation. The anode may be shaped as a beveled disk and, in some embodiments, may be rotated via an electric motor. The cathode and anode of the x-ray source 360 may be housed in an airtight enclosure, sometimes referred to as an envelope.

[0043] In some embodiments, the x-ray source 360 may include a radiation object focus which influences the visibility of an image. The radiation object focus may be selected by a user of the system 100 or by a manufacturer of the system 100 based on characteristics such as blurring, visibility, heat-dissipating capacity, or other characteristics. In some embodiments, an operator or user of the system 100 may switch between different provided radiation object foci in a point-of-care setting.

[0044] The detector 370 may be configured to acquire x-ray images and may include the input screen 374. The input screen 374 may include one or more intensifying screens configured to absorb x-ray energy and convert the energy to light. The light may in turn expose a film. The input screen 374 may be used to convert x-ray energy to light in embodiments in which the film may be more sensitive to light than x-radiation. Different types of intensifying screens within the image intensifier may be selected depending on the region of a patient to be imaged, requirements for image detail and/or patient exposure, or any other factors. Intensifying screens may be constructed of any suitable materials, including barium lead sulfate, barium strontium sulfate, barium fluorochloride, yttrium oxysulfide, or any other suitable material. The input screen 374 may be a fluorescent screen or a film positioned directly adjacent to a fluorescent screen. In some embodiments, the input screen 374 may also include a protective screen to shield circuitry or components within the detector 370 from the surrounding environment. The x-ray detector 370 may additionally be referred to as an x-ray sensor.

[0045] The object 380 may be any suitable object to be imaged. In an exemplary embodiment, the object 380 may be the anatomy of a patient including any region of a patient’s anatomy previously mentioned. More specifically, the anatomy to be imaged may include the coronary region. In some embodiments, the object 380 may include man-made structures.

[0046] In some embodiments, the x-ray source 360 and the x-ray detector 370 are mounted to the movable arm 352. In this configuration, the x-ray source 360 and the x-ray detector 370 may be rotated around the object 380 or patient anatomy to acquire images of the object 380 or patient anatomy at different angles. The movable arm 352 may move the x-ray source 360 and detector 370 to any suitable location around the object 380 or patient anatomy. In some embodiments, the movable arm 352 may receive command signals from the system 154 or 164 based on a user input to move the x-ray source 360 and detector 370 to a desired position or angle 390 with respect to the object 380 to be imaged. The arm 352 may be of any suitable type or shape in addition to the one shown in Fig. 3 and may additionally be referred to as a gantry. In some embodiments, the x-ray imaging device 300 may include more than one set of x-ray sources 360 and detectors 370. For example, the x-ray imaging device 300 may be a bi-plane x- ray imaging system. In embodiments in which the x-ray imaging device 300 includes multiple sets of x-ray sources 360 and corresponding x-ray detectors 370, a physician may image the same regions of a patient’s anatomy from multiple angles simultaneously or may image different regions of the patient’s anatomy simultaneously.

[0047] As previously mentioned, the x-ray imaging device 300 may be configured to acquire angiography images. In such embodiments, a contrast agent may be introduced to a patient’s anatomy before imaging. The contrast agent may be used to enhance the visibility of internal structures within a patient’s anatomy. The contrast agent may absorb external x-rays, resulting in decreased exposure on the x-ray detector 370. In other embodiments, in which fluoroscopy images are to be obtained, a contrast agent may not be introduced to the patient anatomy prior to imaging. The contrast agent may be of any suitable type previously listed.

[0048] When an x-ray processing system, such as the x-ray angiography processing system 154 or the x-ray fluoroscopy processing system 164 of Fig. 1, is in communication with the x-ray imaging device 300, various data may be transmitted. This communication includes x-ray imaging data as well as control commands to the x-ray source 360 and/or x-ray detector 370 of the x-ray device 300. In some embodiments, the x-ray imaging device 300 may perform preliminary processing of the x-ray data prior to relaying the data to the processing system. In examples of such embodiments, the x-ray imaging device 300 may perform amplification, filtering, and/or aggregating of the data. In an embodiment, the x-ray image processing system may also supply high- and low- voltage DC power to support operation of the device 300 including circuitry within the device.

[0049] Fig. 4 is a schematic diagram of a processor circuit 410, according to aspects of the present disclosure. The processor circuit 410 or a similar processor circuit may be implemented in any suitable device or system previously disclosed. One or more processor circuits 410 can be configured to perform the operations described herein. The processor circuit 410 can include additional circuitry or electronic components, such as those described herein. In an example, one or more processor circuits 410 may be in communication with transducer arrays, sensors, circuitry, or other components within the intravascular device 146 (Figs. 1, 2), the x-ray source 360, the input screen 374, circuitry, or any other components within the x-ray imaging device 300 (Fig. 3) or angiography device 156 or fluoroscopy device 166 (Fig. 1) and/or the display 132 (Fig. 1), as well as any other suitable component or circuit within the diagnostic system 100. As shown, the processor circuit 410 may include a processor 460, a memory 464, and a communication module 468. These elements may be in direct or indirect communication with each other, for example via one or more buses.

[0050] The processor 460 may include a CPU, a GPU, a DSP, an application-specific integrated circuit (ASIC), a controller, an field programmable gate array (FPGA), another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 460 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0051] The memory 464 may include a cache memory (e.g., a cache memory of the processor 460), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory 464 includes a non-transitory computer-readable medium. The memory 564 may store instructions 466. The instructions 466 may include instructions that, when executed by the processor 460, cause the processor 460 to perform the operations described herein with reference to the devices 146, 156, 166, 300, and/or the systems 134, 144, 154, and/or 164. Instructions 466 may also be referred to as code. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc.

“Instructions” and “code” may include a single computer-readable statement or many computer- readable statements.

[0052] The communication module 468 can include any electronic circuitry and/or logic circuitry to facilitate direct or indirect communication of data between the processor circuit 410, the previously described devices and systems, and/or the display 132. In that regard, the communication module 468 can be an input/output (I/O) device. In some instances, the communication module 468 facilitates direct or indirect communication between various elements of the processor circuit 410 and/or the devices and systems of the diagnostic system 100 (Figs. 1-4).

[0053] Fig. 5 is a flow diagram of a method 500 of co-registering intravascular data with an angiography image, according to aspects of the present disclosure. One or more steps of the method 500 will be described with reference to Figs. 6A-10. As illustrated, the method 500 includes a number of enumerated steps, but embodiments of the method 500 may include additional steps before, after, or in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted, performed in a different order, or performed concurrently. The steps of the method 500 can be carried out by any suitable component within the diagnostic system 100 and all steps need not be carried out by the same component. In some embodiments, one or more steps of the method 500 can be performed by, or at the direction of, a processor circuit of the diagnostic system 100, including, e.g., the processor 460 (Fig. 4) or any other component.

[0054] An advantage of co-registering data from different medical diagnostic modalities includes providing a user of the system 100 with accurate information relating to the position of an intravascular device 146 within the patient anatomy. For example, location information may be displayed on an angiography image obtained at the same angle as the fluoroscopy images received during an intravascular device pullback procedure. The method 500 includes providing location information of the intravascular device 146 in conjunction with an angiography-based roadmap image which may be displayed at any arbitrary angle. In circumstances in which an intravascular device pullback procedure was performed, but angiography images were not obtained at the same angle as fluoroscopy images, the method 500 makes co-registration of the intravascular data onto an angiography-based image still possible. A user of the system 100 may then view exact location information corresponding to intravascular measurements relating to a blood vessel as a visual representation (e.g., numerical/alphanumerical, graphical, symbolic, etc.) overlaid on the angiography-based roadmap image which would appear similar to an angiography image obtained at the same angle as the fluoroscopy images, as will be discussed in more detail. In this way, the user of the imaging system 100 need not estimate the location of measurements from an intravascular device 146 based on separate views of an x-ray image and/or measurement display. [0055] At step 505, the method 500 includes receiving two angiography images depicting the patient vasculature from two different angles. Step 505 will be described with reference to Fig. 6A and Fig. 6B. Fig. 6A is a diagrammatic view of an x-ray angiography image 605 of vessels 630 of the heart 620, according to aspects of the present disclosure. Fig. 6B is a diagrammatic view of an x-ray angiography image 610 of the coronary vessels 630 of the heart 620 shown in Fig. 6A imaged from a different angle 695, according to aspects of the present disclosure. The axes 698 denote that the angiography image 605 is two-dimensional. The axes 699 denotes that the angiography image 610 is two-dimensional.

[0056] The x-ray angiography images 605 and 610 may be acquired via the x-ray imaging device 300 (Fig. 3) or the device 156 (Fig. 1). The x-ray angiography images 605 and 610 are obtained with a contrast agent introduced to the vasculature. This radiopaque contrast agent causes vessels 630 to be more visible on the angiography image. The angiography image 605 may be acquired at an angle 690 in relation to the patient anatomy. For example, the x-ray source 360 and/or the x-ray detector 370 (Fig. 3) may be positioned at some angle 690 from the patient anatomy resulting in the perspective of vessels 630 shown in Fig. 6 A.

[0057] The x-ray angiography image 610 of Fig. 6B may be acquired with the x-ray source 360 and detector 370 positioned at a different angle 695 with respect to the patient anatomy. The angiography image 610 shown in 6B shows the same vasculature of the same heart 620. Due to the different angle 695, however, the vessels 630 of the heart 620 are shown in a different arrangement. The x-ray angiography images 605 and 610 may be two-dimensional images.

[0058] The angiography images 605 and 610 may be acquired via any suitable method. For example, the angiography images 605 and 610 may be obtained by the same x-ray imaging device 156. As mentioned, the x-ray angiography device 156 may be or include the x-ray imaging device 300 of Fig. 3 or any components described with reference to Fig. 3. The vasculature of the heart 620 may be positioned between the x-ray source 360 and detector 370 (Fig. 3) at some angle 690. The angiography image 605 may then be obtained by the device 156, processed with the x-ray angiography processing system 154, and stored on a memory in communication with the co-registration processing system 134 (Fig. 1). The x-ray source 360 and detector 370 may then be positioned to angle 695 immediately after acquiring the data corresponding to the image 605. The angiography image 610 may then be obtained, processed, and stored on a memory in communication with the co-registration processing system 134 (Fig. 1). During this process, the patient may remain unmoved. In some procedures, some amount of time may pass between the acquisition of angiography image 605 and image 610.

[0059] The angles 690 and 695 may be any suitable angles with respect to the patient anatomy. For example, in some embodiments, the angles 690 and 695 may correspond to left anterior oblique (LAO) and right anterior oblique (RAO) views respectively or vice versa. The angles 690 and 695 may also correspond to left posterior oblique (LPO) and right posterior oblique (RPO) views or any other suitable angle or view. In some embodiments, the angles 690 and 695 are orthogonal to one another. To ensure accurate 3D angiography -based model formation, as will be discussed with reference to step 510, the angles 690 and 695 may be positioned at least 10° from one another. In some embodiments, the x-ray source 360 and the x- ray detector 370 may be mounted to a c-arm similar to the arm 352 (Fig. 3) which may be moved around the patient to any suitable angle. In some embodiments, additional angiography images from additional angles similar to images 605 and 610 may be obtained with the x-ray angiography device 156.

[0060] In some embodiments, the x-ray angiography images 605 and 610 may be obtained with a bi-plane angiography system and method similar to the bi-plane x-ray imaging device discussed with reference to Fig. 3. For example, the x-ray angiography device 156 or 300 may include two sets of x-ray sources and x-ray detectors which may image a patient anatomy simultaneously from two different angles. In such an embodiment, the vasculature of the heart 620 may be positioned between one x-ray source and detector at some angle 690 and between a second x-ray source and detector at some different angle 695 at the same time. The angles 690 and 695 may be orthogonal to one another or may differ. The x-ray angiography device 156 may then obtain the image 605 and the image 610 simultaneously. Both images may then be processed with the x-ray angiography processing system 154 and stored on a memory in communication with the co-registration processing system 134 (Fig. 1).

[0061] At step 510, the method 500 includes generating a three-dimensional model 700 of the patient vasculature based on the two x-ray angiography images 605 and 610. Step 510 will be described with reference to Fig. 7, which is a diagrammatic view of an x-ray angiography-based three-dimensional model 700 of the coronary vessels 630 of the heart 620 shown in Figs. 6A and 6B, according to aspects of the present disclosure. The axes 799 denote that the model 700 is three-dimensional. [0062] A three-dimensional angiography-based model 700 may be reconstructed based on the two x-ray angiography images 605 and 610 according to any suitable method. For example, two angiography images 605 and 610 may be received by the system 100. Features of the two- dimensional images may be identified in each image. The features may include features of the coronary vasculature or coronary arterial tree of the heart 620.

[0063] In some embodiments, the system 100 or a user of the system 100 may identify or mark a series of points within each angiography image 605 and 610 to define centerlines of depicted vessels including major vessels and branching vessels. The same vessels are identified in each of the two angiography images 605 and 610. The system 100, or a user of the system 100, may then identify common features depicted in both angiography images 605 and 610 including, but not limited to, occlusions or regions of constrictions of a vessel, tortuosity of a vessel, bifurcations, or lengths of a vessel, among other features. These features may be identified as points or locations within the angiography image 605 or 610. For example, for the angiography image 605, the location of a feature such as a bifurcation may be identified as a two-dimensional coordinate. This coordinate may be included within a matrix, A , along with other two-dimensional coordinates corresponding to other identified features. Similarly, the same bifurcation would have an additional two-dimensional coordinate as identified in the angiography image 610. This coordinate would be included in a matrix A₂, along with the other two-dimensional coordinates corresponding to the same features identified in the image 605. In this way, the matrices A₁ and A₂ would contain the same number of two-dimensional coordinates corresponding to the same features in both the images 605 and 610.

[0064] For each matrix, A₁ and A₂, a vector R, may also be determined or received corresponding to the angle at which the angiography image 605 and the angiography image 610 were acquired respectively. Specifically, a vector

corresponding to the angle 690 may be stored in conjunction with the matrix A₁ and a vector R₂ corresponding to the angle 695 may be stored in conjunction with the matrix A₂. In some embodiments, a calibration matrix K may additionally be determined for each matrix, A₁ and A₂. A matrix K may be stored in conjunction with the matrix A₁ and a matrix K₂ may be stored in conjunction with the matrix A₂. Additional values, constants, vectors, or matrices may additionally be determined for either matrix A₁ and/or matrix A₂. For example, values, constants, vectors, or matrices may be determined corresponding to the position of the x-ray source 360 (Fig. 3) and/or the x-ray detector 370 (Fig. 3) in relation to the location of the imaged anatomy, the conversion of points or coordinates form one coordinate system to another or from one dimension to another, scaling, any applicable offsets in the determined coordinates, or any other additional data.

[0065] Based on the acquired data relating to each image 605 and 610, including the matrices A₁ and A₂, the vectors

and R₂, and/or the calibration matrices K and K₂ if applicable, an equation may be developed projecting the locations of the identified features from their two- dimensional positions within the images 605 and 610 into three-dimensional space. Specifically, an equation for the angiography image 605 may be developed similar to M = R^K^A^ in which M corresponds to the three-dimensional coordinates of the locations of the identified features in the three-dimensional angiography-based model 700. An additional similar equation, M = R₂K₂A₂, may be developed corresponding to the angiography image 610. As the matrices A₁ and A₂ include two-dimensional coordinates for each location of identified features and the matrix M includes three-dimensional coordinates, the two equations listed above for the images 605 and 610 together form a system of equations which may be solved to determine the three- dimensional coordinates of each identified feature to create the three-dimensional angiographybased model 700.

[0066] It is noted that in order to create the three-dimensional angiography-based model 700, at least two angiography images from two different angles or views must be acquired or provided to the system 100. The angles at which each image was acquired must also be known, though these angles may be arbitrary. The anatomy shown in the two or more input angiography images, similar to the images 605 or 610, may have contrast agent introduced.

[0067] The method of generating the three-dimensional angiography-based model 700 may include any suitable method or process and may include some features similar to those described in U.S. Patent No. 6501848, titled “METHOD AND APP ARTUS FOR THREE- DIMENSIONAL RECONSTRUCTION OF CORONARY VESSELS FROM ANGIOGRAPHIC IMAGES AND ANALYTICAL TECHNIQUES APPLIED THERETO” which is hereby incorporated by reference in its entirety. Generating the three-dimensional angiography-based model 900 may additionally include some features similar to those described in the publication entitled, “3-D RECONSTRUCTION OF CORONARY ARTERIAL TREE TO OPTIMIZE ANGIOGRAPHIC VISUALIZATION,” IEEE Trans. Med. Imag., vol. 19, no. 4, pp. 318-336, April 2000, doi: 10.1109/42.848183 by S. J. Chen and J. D. Carroll, which is also hereby incorporated by reference in its entirety.

[0068] At step 515, the method 500 includes receiving x-ray fluoroscopy images 810 of the patient vasculature from an arbitrary angle 895 while an intravascular device 820 moves through a blood vessel and acquires intravascular data. Step 515 will be described with reference to Fig. 8, which is a diagrammatic view illustrating a relationship between x-ray fluoroscopy images 810, intravascular data 830, a path 840 defined by the motion of an intravascular device 820, an x-ray angiography-based 3D model 700, and a roadmap image 880 based on the angiographybased model, according to aspects of the present disclosure.

[0069] At step 515, the patient anatomy may be imaged with an x-ray device while a physician performs a pullback with an intravascular device 820 such that the intravascular device 820 moves through a blood vessel of the anatomy. The x-ray device used to obtain the fluoroscopy images 810 may be substantially similar to the x-ray device 300 of Fig. 3 or the x- ray fluoroscopy imaging device 166 of Fig. 1. The x-ray fluoroscopy images 810 may include multiple images acquired over time to form a fluoroscopy image stream. In some embodiments, the fluoroscopy images 810 may be obtained while no contrast agent is present within the patient vasculature. Such an embodiment is shown in the fluoroscopy images 810 in Fig. 8. The radiopaque portion of the intravascular device 820 is visible within the displayed fluoroscopy image 810 as indicated by the circle 825. The fluoroscopy images 810 may correspond to a continuous image stream of fluoroscopy images and may be obtained as the patient anatomy is exposed to a reduced dose of x-radiation. It is noted that the fluoroscopy images 810 may be acquired with the x-ray source 360 and the x-ray detector 370 positioned at any suitable angle 895 in relation to the patient anatomy such that the fluoroscopy images 810 depict a view of the patient anatomy at an angle 895. The angle 895 of the source 360 and detector 370 need not be the same as either of the angles 690 and 695 of the angiography images 605 or 610 previously acquired as described with reference to Figs. 6A and 6B, though it may be. The angle 895 may be any suitable angle. The fluoroscopy images 810 are two-dimensional as shown by the axes 898.

[0070] The intravascular device 820 may be any suitable intravascular device. The device may be substantially similar to the device 146 of Figs. 1 and 2, including any of its described embodiments. As the intravascular device 820 moves through the patient vasculature, the x-ray imaging system may acquire multiple fluoroscopy images 810 showing the radiopaque portion of the intravascular device 820. In this way, each fluoroscopy image 810 may depict the intravascular device 820 positioned at a different location such that the x-ray system may track the position of the intravascular device 820 over time.

[0071] As the intravascular device 820 is pulled through the patient vasculature, it may acquire intravascular data 830. In an example, the intravascular data 830 shown in Fig. 8 may be IVUS images. However, the intravascular data 830 may be any suitable data, including IVUS images, FFR data, iFR data, OCT data, or any other measurements or metrics relating to blood pressure, blood flow, lumen diameter, or other physiological data acquired during a pullback of an intravascular device.

[0072] As the physician pulls the intravascular device 820 through the patient vasculature, the system 100 may co-register the intravascular data 830 to the fluoroscopy images 810, as indicated by the arrow 862. In this way, each intravascular measurement acquired by the intravascular device 820 may be associated with a position within the patient anatomy. For example, the IVUS image 830 shown in Fig. 8 may be associated with the fluoroscopy image 810 shown. The IVUS image 830 may be an image acquired by the intravascular device 820 at a position within the vasculature and within the fluoroscopy image 810 as shown by the circle 825. Similarly, an additional IVUS image 830 may be associated with an additional fluoroscopy image 810 showing the intravascular device 820 at a new location within the image 810.

[0073] Any suitable number of IVUS images or other intravascular data 830 may be acquired during an intravascular device pullback and any suitable number of fluoroscopy images 810 may be obtained. In some embodiments, there may be a one-to-one ratio of fluoroscopy images 810 and intravascular data 830. In other embodiments, there may be differing numbers of fluoroscopy images 810 and/or intravascular data 830. The process of co-registering the intravascular data 830 with the fluoroscopy images 810 at step 515 may include some features similar to those described in U.S. Patent No. 7930014, titled, “VASCULAR IMAGE COREGISTRATION,” and filed January 11, 2006, which is hereby incorporated by reference in its entirety. The co-registration process may also include some features similar to those described in U.S. Patent No. 8,290,228, U.S. Patent No. 8,463,007, U.S. Patent No. 8,670,603, U.S. Patent No. 8,693,756, U.S. Patent No. 8,781,193, U.S. Patent No. 8,855,744, and U.S. Patent No. 10,076,301, all of which are also hereby incorporated by reference in their entirety. [0074] The different positions of the intravascular device 820 as shown in the fluoroscopy images 810 may define a two-dimensional path 840, as shown by the arrow 860. The two- dimensional path 840 reflects the path of the intravascular device 820 as it moved through the patient vasculature. The two-dimensional path 840 defines the path as measured by the x-ray device which acquired the fluoroscopy images 810, and therefore shows the path from the same angle 895 at which the fluoroscopy images 810 were acquired. The axes 899 denotes that the path 840 is two-dimensional.

[0075] As shown by the arrow 864, because the two-dimensional path 840 is generated based on the fluoroscopy images 810, each position along the two-dimensional path 840 may be associated with one or more fluoroscopy images 810. As an example, at a location 841 along the path 840, the fluoroscopy image 810 may depict the intravascular device 820 at that same position 841. In addition, because a correspondence was also established between the fluoroscopy images 810 and the intravascular data 830 as shown by the arrow 862, intravascular data 830, such as the IVUS image shown, may also be associated with the location 841 along the path 840 as shown by the arrow 866.

[0076] At step 520, the method 500 includes co-registering the intravascular data 830 to the x-ray angiography-based 3D model 700. For example, a processor circuit can apply a 3D transformation matrix to project a 2D model to a 3D model based on the angle at which the 2D view is taken. The step 520 will also be described with reference to Fig. 8. After the two- dimensional path 840 is generated based on the fluoroscopy images 810, the path 840 may be projected onto the three-dimensional angiography-based model 700 described with reference to Fig. 7. Because the angle at which the fluoroscopy images 810 were obtained is known, this same angle may be used to project the two-dimensional path 840 onto the angiography-based three-dimensional model 700 as shown in Fig. 8. In an example, the coordinates of the two- dimensional path 840 may be stored as an additional matrix A₃. The matrix A₃ may then be multiplied by a transformation matrix corresponding to the angle at which the fluoroscopy images 810 were obtained and the three-dimensional coordinates of same vessel within the angiography-based 3D model 700 as stored in matrix M described previously. The result may map the locations of pathway 840 to the 3D angiography-based model 700. This projection of the 2D path 840 to the 3D angiography-based model 700 may also use any of the same or similar mathematical processes relating to matrix transformations or matrix projections previously presented with reference to Fig. 7. The system 100 may use the known angle 895 at which the fluoroscopy images 810 were obtained during the matrix transformation process. In this way, the two-dimensional path 840 may become a three-dimensional path 850 overlaid on the three- dimensional model 700. Just as different fluoroscopy images 810 and intravascular data 830 were associated with various locations along the two-dimensional path 840, the fluoroscopy images 810 and intravascular data 830 may be associated with the same locations along the three-dimensional path 850 on the angiography-based three-dimensional model 700 as shown by the arrow 868 and the arrow 869. For example, the same location 841 may be identified on the angiography-based model 700 using any of the techniques previously described. The same fluoroscopy images 810 associated with the location 841 on the two-dimensional path 840 may be associated with the same location 841 on the three-dimensional path 850 and three- dimensional model 700. Similarly, the same intravascular data 830 associated with the location 841 on the two-dimensional path 840 may also be associated with the same location 841 on the three-dimensional path 850 and three-dimensional model 700.

[0077] In some embodiments, the two-dimensional path 840 need not be generated by the system 100. Rather, the locations of the intravascular device 820, as shown in the fluoroscopy images 810, may be directly projected to the three-dimensional angiography-based model 700 using the same or similar matrix projection techniques previously described. The intravascular data may additionally be directly associated with the three-dimensional model 700 without generating a two-dimensional path 840.

[0078] The procedures described thus far, including obtaining two x-ray angiography images 605 and 610 (Figs. 6A and 6B) at different angles, and obtaining intravascular data 630 and fluoroscopy images 810 may be performed at various times in relation to one another. In some embodiments, each procedure may be performed concurrently such that one procedure is completed immediately following another. In other embodiments, more time may pass between each procedure. The amount of time between each procedure may be limited to prevent significant change to the patient anatomy between each procedure. Such change may be a result of natural growth, trauma, healing, therapy, or any other event or process which may alter the patient anatomy between procedures. The length of time between each procedure may be between one day and several weeks, several months, or several years. However, the period of time between the listed procedures should not include an event or process which may alter the patient anatomy between procedures.

[0079] At step 525 the method 500 includes projecting the three-dimensional model 700 with the co-registered intravascular data 830 to a two-dimensional plane at the arbitrary angle 897 to generate a roadmap image 880. Step 525 will also be described with reference to Fig. 8.

[0080] After having constructed a three-dimensional model 700 of the patient vasculature tree as shown in Fig. 8 based on the two angiography images 605 and 610, the model 700 may be projected from the three-dimensional space to the two-dimensional space using an inverse of the matrix transformation equations presented with reference to Fig. 7. Projecting the three- dimensional model 700 to the two-dimensional space creates a two-dimensional roadmap image 880 which may be displayed to a user. It is noted that the roadmap image 880 is not an image directly acquired by an imaging device or system. Rather, it is a computer generated, two- dimensional projection of the 3D model. In some aspects, however, the roadmap image 880 may resemble and is based on one or more angiography images received from an x-ray imaging device. In that sense, the roadmap image 880 can be referred to an as an angiography-based image. The intravascular data 830 which was co-registered to the angiography-based three- dimensional model 700 may also be projected to the two-dimensional space with any of the previously mentioned matrix transformation or projection techniques as shown by the arrows 870 and 867. The three-dimensional path 850 may also be projected to the two-dimensional image 880 and appear within the image 880 as a path 872 with any of the previously mentioned matrix transformation or projection techniques. The three-dimensional model 700 may be projected to a two-dimensional image at any arbitrary angle 897, including an angle differing from the angles 690 (Fig. 6A), 695 (Fig. 6B), and/or 895. This allows a user of the system 100 to view the intravascular data 830 overlaid on an angiography-based image at any suitable angle. For example, if a physician desires to view intravascular data overlaid or otherwise in conjunction with a curved vessel, views of different angles of the vasculature would show the curve differently. If the two or more angiography images obtained did not show the region of the curved vessel at an ideal angle, the physician may input to the system 100 any desired angle. The system 100 may then display to the user an angiography-based roadmap image 880 at the desired angle with co-registered data. In this way, a physician may view a patient vasculature with coregistered data from an angle at which no x-ray angiography image was obtained. This is because a 2D projection can be generated at any viewing angle or source angle of the 3D model. The axes 896 denote that the angiography-based roadmap image 880 is two-dimensional. [0081] In other embodiments, a physician may need to view the intravascular data in conjunction with an angiography image obtained at the same angle 895 at which the fluoroscopy images 810 were obtained but may not have acquired an angiography image at that angle 895. The physician may similarly input to the system the desired angle 895 and view the intravascular data 830 overlaid over an angiography-based image 880 showing the vasculature at the angle 895 desired although no angiography image was obtained at that desired angle 895. In an embodiment in which the angle 897 is the same as the angle 895, the path 872 may be substantially similar in shape and orientation to the path 840 previously described.

[0082] At a high level, in the example shown in Fig. 8, the location of the IVUS image 830 is identified in its corresponding fluoroscopy image 810 as shown by the arrow 862. The location at which that image 830 was obtained along the vessel may then be identified as the point 841 along the path 840. Through the matrix transformation techniques discussed with reference to Fig. 7, the IVUS image 830 and its corresponding location along the path 840 may be projected onto the angiography-based model 700 as shown by the arrow 868, such that the point 841 is also identified along the vessel in the three-dimensional model 700. At step 525, the three- dimensional path 850 may be inversely projected to the two-dimensional path 872, identifying the same point 841 at which the image 830 was obtained. This same process may be used to coregister any suitable intravascular data with a three-dimensional angiography-based model 700 which may then be displayed as a two-dimensional angiography-based roadmap image 880 at any angle 897.

[0083] At step 530, the method 500 includes displaying the roadmap image 880 with a visual representation (e.g., numerical/alphanumerical, graphical, symbolic, etc.) of the intravascular data 830. Step 530 will be described with reference to Figs. 9 and 10. Fig. 9 is a diagrammatic view of a graphical user interface 900 displaying intravascular data 910 co-registered to an angiography-based roadmap image 880, according to aspects of the present disclosure. Fig. 9 additionally depicts an indicator 915, an image longitudinal display (ILD) 912, an indicator 905, a patient name 950, and a time metric 952.

[0084] The angiography-based image 880 with co-registered intravascular data 910 may be displayed to a user in any suitable format. For example, as shown in Fig. 9, the angiography- based image 880 may be displayed adjacent to the corresponding intravascular data 910. The intravascular data 910 may be an IVUS image. In other embodiments, co-registered intravascular data 910 may include any other suitable images, metrics, or other data and may be overlaid over the angiography-based image 880 or arranged or displayed in any other suitable configuration. [0085] In the embodiment shown in Fig. 9, the indicator 905 is positioned over the angiography-based image 880 at a location along a vessel imaged by the intravascular device 820 (Fig. 8). The IVUS image 910 displayed adjacent to the angiography-based image 880 is an image acquired by the intravascular device 820 at the location identified by the indicator 905. The image 910 may be included within the intravascular data 830 of Fig. 8. In one example, the location identified by the indicator 905 could correspond to the location 841 previously identified in Fig. 8. The fluoroscopy image 810 and IVUS image 830 shown in Fig. 8 may be associated with the location 841 on the angiography-based model 700 and subsequently the angiography-based image 880 in Fig. 8 through three-dimensional to two-dimensional matrix transformation. This allows the IVUS image obtained at the location 841 to be displayed alongside the angiography-based image 880 indicating the location 841 at which the IVUS image was obtained via the indicator 905. In some embodiments, a user of the system 100 may also select an additional IVUS image to be displayed in the graphical user interface 900. As a different IVUS image is selected, the indicator 905 may move to a different location along the vessel corresponding to the location at which the selected IVUS image was obtained. In some embodiments, a user of the system 100 may additionally move the indicator 905 along any vessel shown in the angiography-based image 880 and an IVUS image corresponding to the selected location would be displayed to the user if an IVUS image was obtained at the selected location. [0086] In some embodiments, additional images may be included and displayed to a user of the system 100, including the image longitudinal display (ILD) 912. The ILD 912 may provide the user with a longitudinal view of the vessel imaged with the intravascular device. Specifically, one end of the ILD 912 may correspond to the proximal most region of the imaged vessel and the opposing end of the ILD 912 may correspond to the distal most region of the imaged vessel. The ILD 912 may provide a visual representation (e.g., numerical/alphanumerical, graphical, symbolic, etc.) of relative diameters of the imaged vessel at all positions along the imaged vessel. The ILD 912 may include an indicator 915. The indicator 915 may correspond to the position of the intravascular device relative to the entire imaged vessel at the location at which the displayed IVUS image was obtained. In this way, as the indicator 905 is moved by a user to a different location along the vessel, a different IVUS image would be displayed adjacent to the angiography-based image 880 and the indicator 915 would also move to a different corresponding position within the ILD 912. In some embodiments, a user may be able to move the indicator 915 to a different location within the ILD 912 as well and cause the system 100 to recall and display an associated IVUS image as well as move the indicator 905 to a different corresponding position within the angiography-based image 880.

[0087] The system 100 may display additional images or metrics to a user. For example, the system 100 may display any of the previously discussed images such as the fluoroscopy images 810, the two-dimensional path 840, the three-dimensional path 850, the projected two- dimensional path 872, the angiography-based model 700 (Fig. 8), or the angiography images 605 (Fig. 6A) and 610 (Fig. 6B). The system 100 may additionally display any suitable indicators or metrics associated with any of these images.

[0088] In some embodiments, the system 100 may display to a user pressure data, including any of data 1010 of Fig. 10 discussed hereafter in conjunction with an IVUS image 910. For example, an IVUS image 910 may be saved on a memory in communication with the system 100 along with one or more pressure measurements, flow measurements, volume measurements, or other measurements associated with the position within the vessel shown in the IVUS image 910. In this way, overlaid over, adjacent to, or in any other position within the graphical user interface 900, these additional measurements may be displayed.

[0089] In some embodiments, the system 100 may not complete step 525 of the method 500 of projecting the angiography-based model 700 to the two-dimensional plane to create the angiography-based image 880. Rather, the system 100 may display to a user the angiographybased model 700 with the co-registered intravascular data in place of the angiography-based image 880. In such an embodiment, the user may be able to rotate the model 700 with an input to the system 100 to view the model 700 with the co-registered intravascular data from any desired angle.

[0090] Additional metrics displayed to a user may include the patient’s name 950 and a time metric 952 indicating either the date and time a procedure was performed, such as the intravascular imaging procedure or any other described procedure. The time metric 952 may additionally convey a length of time of a procedure, a date and time of a scheduled procedure, or any other suitable time metric. The system 100 may also display to a user any other suitable metrics relating to the identification of the patient, characteristics of the patient, medical history of the patient, information relating to previous exams, or any other suitable data. The system 100 or any suitable processor of the system 100 may be in communication with a memory or server containing all of this and any other suitable data and/or metrics which may be displayed to the user.

[0091] Fig. 10 is a diagrammatic view of a graphical user interface 1000 displaying intravascular data 1010 co-registered to an angiography-based roadmap image 880, according to aspects of the present disclosure. In the example graphical user interface 1000 shown in Fig. 10, the intravascular data 1010 may correspond to intravascular data other than IVUS data. For example, the intravascular 1010 may correspond to iFR data, but in other embodiments, the intravascular data may alternatively correspond to FFR data, or any other suitable intravascular data. The intravascular data 1010 may be included in the intravascular data 830 of the Fig. 8. The intravascular data 1010 shown in Fig. 10 includes pressure difference indicators 1011, an indicator 1016, pressure metrics 1020, a chart 1025, a region 1027, a graphical element 1012, and metrics 1014.

[0092] As shown in Fig. 10, visual representations (e.g., numerical/alphanumerical, graphical, symbolic, etc.) corresponding to intravascular data 1010 may be overlaid over the angiography-based image 880 or displayed adjacent to the angiography-image 880 or in any other configuration. In the embodiment shown in Fig. 10, the intravascular data 1010 includes multiple pressure difference indicators 1011. The pressure difference indicators 1011 may convey to a user the severity of differences in pressure at various locations along the measured vessel. For example, each symbol can be representative of a unit change in the pressure ratio (e.g., 0.01 change in iFR). Accordingly, the number of indicators 1011 may correspond to the severity of pressure difference. For instance, near an occlusion, the difference in pressure may be the most significant. A large number of indicators 1011 may be positioned by the location of the occlusion. In the embodiment shown, the indicators 1011 may be positioned extending in a straight line perpendicular to the vessel. However, the pressure difference indicators 1011 may be arranged in any suitable manner. For example, they may not extend in a straight line, but may extend in any angled or curvilinear line. The indicators 1011 may also be arranged according to any suitable arrangement or pattern which may convey to a user any suitable metric associated with the vessel at a particular location. Although the pressure difference indicators 1011 are of a circular shape in Fig. 10, the indicators 1011 may be of any suitable type. For example, they may be of any suitable geometric or non-geometric shape or size or may be or include any suitable alphanumeric characters.

[0093] The chart 1025 adjacent to the angiography-based image 880 may indicate intravascular pressure at all locations along the measured length of the vessel. For example, an x- axis of the chart 1025 may indicate the distance of locations along the vessel from the most distal or most proximal position within the vessel at which intravascular measurements were obtained. A y-axis of the chart 1025 may indicate the quantity of intravascular measurement, in this case, iFR measurement data. In some embodiments, a user of the system 100 may select a region 1027 within the chart 1025. The region 1027 corresponds to a length of the measured vessel. The region 1027 may additionally correspond to the indicator 1016 overlaid on the angiography - based image 880. The indicator 1016 illustrates the same selected length of vessel on the angiography-based image 880. In some embodiments, the selected length may be selected by the user or the system 100 either on the angiography-based image 880 or on the chart 1025.

[0094] Upon selection of a region 1027 and/or length shown by the indicator 1016, the system 100 may generate and display one or more metrics associated with the selected length of vessel. For example, the metrics 1020 may include metrics such as iFR or other measurements relating to a drop or change in pressure across the selected region 1027. Any additional metrics may also be displayed, such as pressure data related to the distal most location within the selected region 1027, the proximal most location, an average pressure metric, or any other suitable metrics. The metrics 1020 may additionally include pressure or other intravascular data related to the measured vessel such as an iFR measurement at the distal most measured position of the vessel. The metrics 1020 may additionally include any other suitable intravascular data or metrics, such as average pressure or iFR measurements along the entire measured portion of the vessel, change in pressure or iFR measurements along the entire measured portion of the vessel, or any other suitable metrics. The metrics 1020 may be displayed in any suitable location within the graphical user interface, including overlaid on the angiography-based image 880, adjacent to or near the angiography-based image 880, overlaid on the chart 1025, or adjacent to or near the chart 1025, or at any other suitable position and in any other suitable arrangement, orientation, or organization. [0095] Upon selection of a region 1027 and/or length shown by the indicator 1016, the system 100 may also generate the graphical element 1012. The graphical element 1012 may display the same, similar, or different metrics associated with the selected region 1027. The metrics 1014 shown within the graphical element 1012 may indicate the length of the selected region 1027 and the change or drop in pressure or iFR measurements along the selected region 1027. The metrics 1014 may additionally or alternatively include any other suitable metrics including any of those listed with reference to metrics 1020. Similar to the metrics 1020, the metrics 1014 may be displayed in any suitable location within the graphical user interface 1000, including overlaid on the angiography-based image 880, adjacent to or near the angiographybased image 880, overlaid on the chart 1025, or adjacent to or near the chart 1025, or at any other suitable position and in any other suitable arrangement, orientation, or organization.

[0096] The system 100 may also display to a user any other suitable metrics relating to the identification of the patient, characteristics of the patient, medical history of the patient, information relating to previous exams, or any other suitable data. The system 100 may be in communication with a memory or server containing all of this and any other suitable data and/or metrics which may be displayed to the user. As stated with reference to the graphical user interface 900 of Fig. 9, the system 100 may display the intravascular data, including the pressure data 1010 shown in Fig. 10, overlaid on the angiography-based three-dimensional model 700. For example, the graphical user interface 1000 may include a depiction of the model 700 with pressure difference indicators 1011 displayed along the same vessel and shown at any angle. Any other metrics associated with the intravascular data 1010 may additionally be displayed overlaid on, or otherwise in conjunction with the three-dimensional model 700. In such an embodiment, the user may be able to rotate the model 700 with an input to the system 100 to view the model 700 with the co-registered intravascular data from any desired angle.

[0097] It is understood that the data, metrics, features, graphical elements, visual representations, images, or any other aspects of the graphical user interfaces 900 (Fig. 9) and/or 1000 are merely exemplary and any other additional data, metrics, features, graphical elements, visual representations, images, or any other aspects are fully contemplated. In addition, the arrangement of the elements listed above is also exemplary. Any suitable configuration, arrangement, or organization is also fully contemplated. [0098] Persons skilled in the art will recognize that the apparatus, systems, and methods described above can be modified in various ways. Accordingly, persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.

Claims

CLAIMS What is claimed is:

1. A co-registration system, comprising: a processor circuit configured for communication with a display, an x-ray fluoroscopy imaging device, and an intravascular catheter or guidewire, wherein the processor circuit is configured to: receive, from the x-ray fluoroscopy imaging device, a plurality of x-ray fluoroscopy images of a blood vessel while the intravascular catheter or guidewire moves through the blood vessel, wherein the plurality of x-ray fluoroscopy images comprise a view of the blood vessel at a first angle; receive, from the intravascular catheter or guidewire, intravascular data representative of the blood vessel while the intravascular catheter or guidewire moves through the blood vessel; generate a roadmap image of the blood vessel based on x-ray angiography data, wherein the roadmap image comprises a view of the blood vessel at a second angle different than the first angle; co-register the intravascular data to the roadmap image; and output, to the display, the roadmap image and a visual representation of the intravascular data overlaid on the roadmap image.

2. The system of claim 1, wherein the processor circuit is configured to: receive the x-ray angiography data from an x-ray angiography device in communication with the processor circuit, wherein the x-ray angiography data comprises a first x-ray angiography image of the blood vessel and the second x-ray angiography image of the blood vessel, wherein the first x-ray angiography image and the second x-ray angiography image are obtained at different angles; generate a three-dimensional (3D) model of the vessel based on the x-ray angiography data; and

35 co-register the intravascular data to the 3D model of the vessel based on the plurality of x-ray fluoroscopy images.

3. The system of claim 2, wherein the first angle is different than the angles at which the first x-ray angiography image and the second x-ray angiography image are obtained.

4. The system of claim 2, wherein the plurality of x-ray fluoroscopy images comprise two-dimensional (2D) images, wherein the processor circuit is configured to use a matrix transformation to project locations of the intravascular data from the 2D images to the 3D model to co-register the intravascular data to the 3D model.

5. The system of claim 4, wherein the processor circuit is configured to use an angle at which the plurality of x-ray fluoroscopy images were obtained to project the locations of the intravascular data from the 2D images to the 3D model with the matrix transformation.

6. The system of claim 2, wherein the processor circuit is configured to use a matrix transformation to project the 3D model to a 2D plane oriented at the second angle to generate the roadmap image.

7. The system of claim 6, wherein the roadmap image is a computer-generated representation of the vessel.

8. The system of claim 7, wherein the roadmap image is a 2D image.

9. The system of claim 6, wherein the processor circuit is configured to use the matrix transformation to project locations of the intravascular data in the 3D model to the 2D plane to co-register the intravascular data to the roadmap image.

36

10. The system of claim 2, wherein the processor circuit is configured to output, to the display, the 3D model and the visual representation of the intravascular data overlaid on the 3D model.

11. The system of claim 2, further comprising: the x-ray angiography device.

12. The system of claim 1, wherein the processor circuit is configured to output, to the display, a visualization of the intravascular data corresponding to a location of the visual representation along the blood vessel in the roadmap.

13. The system of claim 1, wherein the intravascular data comprises at least one of pressure data, flow data, or imaging data.

14. The system of claim 1, further comprising: the intravascular catheter or guidewire.

15. The system of claim 1, further comprising: the x-ray fluoroscopy device.

16. A co-registration method, comprising: receiving, at a processor circuit in communication with an x-ray fluoroscopy imaging device, a plurality of x-ray fluoroscopy images of a blood vessel while an intravascular catheter or guidewire moves through the blood vessel, wherein the plurality of x-ray fluoroscopy images comprise a view of the blood vessel at a first angle; receiving, at the processor circuit, intravascular data representative of the blood vessel from the intravascular catheter or guidewire while the intravascular catheter or guidewire moves through the blood vessel; generating, with the processor circuit, a roadmap image of the blood vessel based on x- ray angiography data, wherein the roadmap image comprises a view of the blood vessel at a second angle different than the first angle; co-registering, with the processor circuit, the intravascular data to the roadmap image; and outputting, to a display in communication with the processor circuit, the roadmap image and a visual representation of the intravascular data overlaid on the roadmap image.