Stent expansion display, system and method

Abstract

The present disclosure relates in part to systems and methods for assessing stent / scaffold expansion in a vessel on an accelerated time scale after stent / scaffold placement and expansion. In one embodiment, the method generates a first representation of a stented segment of a vessel indicating a level of stent expansion; determines a first end of the stent and a second end of the stent using detected stent struts; and generates a second representation of the segment of the vessel by interpolating a lumen contour using offset distances from the first end and from the second end.

Description

[0001] This application is a divisional application of a patent application with an application date of May 29, 2019, application number 201980048432.0, and invention name “Stent Expansion Display, System and Method”.

[0002] Related Applications

[0003] This application claims priority to U.S. Provisional Application No. 62 / 677,623, filed May 29, 2018, which is incorporated herein by reference in its entirety. Technical Field

[0004] The present disclosure relates generally to the field of systems and methods for vascular system imaging and data collection. In particular, the present disclosure relates to methods for assessing stent expansion levels and presenting relevant diagnostic information. Background Art

[0005] Coronary artery disease is one of the leading causes of death worldwide. The ability to better diagnose, monitor and treat coronary artery disease can have life-saving importance. Intravascular optical coherence tomography (OCT) is a catheter-based imaging modality that uses light to peek into the coronary artery wall and generate images of the coronary artery wall for study. Using coherent light, interferometry and micro-optics, OCT is able to provide video-rate in vivo tomographic imaging with micron-level resolution within diseased blood vessels. Using fiber optic probes to view subsurface structures with high resolution makes OCT particularly useful for minimally invasive imaging of internal tissues and organs. This level of detail made possible by OCT allows users to diagnose and monitor the progression of coronary artery disease.

[0006] OCT imaging of various parts of a patient's body provides physicians and others with a useful diagnostic tool. For example, imaging of a coronary artery by intravascular OCT can reveal the location of a narrowing or stenosis. This information helps cardiologists choose between invasive coronary artery bypass surgery and less invasive catheter-based procedures such as angioplasty or stent delivery. Although stent delivery is a popular option, it has its own associated risks.

[0007] A stent is a tubular structure usually formed of a mesh. It can be inserted into a blood vessel and expanded to counteract a stenotic condition that constricts blood flow. Stents are usually made of metal or polymer stents. They can be placed to the site of the stenosis via a catheter. During cardiovascular surgery, a stent can be delivered to the site of the stenosis via a guidewire through a catheter and expanded using a balloon. Typically, the stent is expanded using a preset pressure to expand the lumen of the stenotic vessel.

[0008] When positioning a stent, there are several factors that influence patient outcomes. In some procedures, the stent should be expanded to a diameter that corresponds to the diameter of the adjacent healthy vessel segment. Overexpansion of the stent can result in extensive damage to the vessel, predisposing it to dissection, disarticulation, and intramural bleeding. Underexpansion of the stent may result in inadequate expansion of the vessel. If portions of the stent fail to contact the vessel wall, the risk of thrombosis may be increased. An underexpanded stent may not restore normal flow. Proper stent expansion is a difficult problem to solve.

[0009] There are other challenges associated with stent placement and related procedures. Visualizing stent placement relative to the wall of a blood vessel using an angiography system has been shown to be challenging. Manual review of images to determine stent position on a per-image basis is also prone to error.

[0010]

[0006] Therefore, a need exists for systems, methods, and devices that provide useful diagnostic information related to stent expansion.

[0011] The present disclosure addresses these challenges and others. Summary of the invention

[0012] The present disclosure relates in part to a method for evaluating stent / scaffold expansion in a blood vessel defining a lumen. In various embodiments, the blood vessel is an artery. The method may include one or more of the following: scanning a stented blood vessel using a first imaging system to obtain a first set of blood vessel image data; storing the first set of blood vessel image data in an electronic memory device in electronic communication with the first imaging system; detecting stent struts along the length of the stented blood vessel using one or more software modules; generating a first representation of a segment of the blood vessel that indicates a level of stent expansion; determining a first end of the stent and a second end of the stent using the detected stent struts; defining a first offset distance (D1) from the first end of the stent and a second offset distance (D2) from the second end of the stent; generating a second representation of the segment of the blood vessel using D1 and D2 in combination with a tapered profile of the segment; and assessing the level of target stent expansion along the segment of the blood vessel by comparing a first value associated with the first representation and a second value associated with the second representation at different locations along the length of the segment.

[0013] In one embodiment, scanning the blood vessel is performed using optical coherence tomography, ultrasound, x-ray based imaging, interferometric imaging, 2D imaging, MRI, 3D imaging, magnetic imaging, or optical imaging. In one embodiment, the blood vessel receives one or more stents during a first procedure, wherein scanning the stented blood vessel is performed as a diagnostic analysis as an extension of the first procedure.

[0014] In one embodiment, the first representation is a first lumen profile of a stented vessel, wherein the lumen profile is generated based on an actual level of expansion of the stent along the length of the segment. In one embodiment, the second representation is a second lumen profile generated based on geometric values ​​of the vessel for each of D1 and D2, wherein the second lumen profile is interpolated based on such geometric values ​​and a tapered profile of the vessel.

[0015] In one embodiment, the method further comprises detecting one or more side branches along the segment, wherein the interpolation of the second lumen contour is generated using the one or more detected side branches.In one embodiment, the geometric value of the vessel is selected from the group consisting of area, diameter, chord, Euclidean distance metric, and volume.

[0016] In one embodiment, wherein assessing the target stent expansion level further comprises determining the extent of stent expansion relative to a stent expansion threshold using a ratio of a first value of the first lumen contour to a second value of the second lumen contour at a plurality of locations along the segment.

[0017] In one embodiment, the first representation includes one or more views of the vessel, wherein the one or more views of the vessel display representations of detected stent struts and a lumen of the vessel. In one embodiment, the scanning of the stented vessel is performed using optical coherence tomography, angiography, ultrasound, x-ray, optical imaging, pressure sensing, flow sensing, and tomographic imaging. In one embodiment, the scanning of the stented vessel is performed using an intravascular data collection probe that is pulled back through the vessel. In one embodiment, the scanning of the stented vessel is performed using one or more shadows or reflections from the first set of vessel image data.

[0018] In one embodiment, when placing the stent, D1 and D2 are selected based on proximity to a user-selected target landing zone. In one embodiment, the method further comprises generating a vessel lumen contour using one or more computing devices after deploying the stent in the vessel. In one embodiment, the method further comprises displaying one or more views of the vessel and / or first vessel representation, and displaying one or more visual cues indicating areas of under-expanded stents along the length of the vessel segment.

[0019] In one embodiment, the method further comprises detecting side branches along the length of the segment of the blood vessel and displaying the side branches relative to the lumen. In one embodiment, the side branches are displayed as dots, ellipses, circles or other shapes relative to the first representation. In one embodiment, the first representation is displayed using a user interface of an imaging system. In one embodiment, the method further comprises scanning the blood vessel with an angiography system and co-registering the angiography data with the detected stent struts and a first visual cue (which indicates that the stent expansion is above the stent expansion threshold) and a second visual cue (which indicates that the stent expansion is below the stent expansion threshold). In one embodiment, the method further comprises visually emphasizing an area of ​​the first representation including the stent. In one embodiment, the user interface emphasizes the area by changing the contrast, intensity, color of another visual element relative to the area. In one embodiment, D1 and D2 are selected from distances in the range of about 0.1 mm to about 1.0 mm. In one embodiment, D1 and D2 are about 0.4 mm.

[0020] The present disclosure relates in part to a processor-based system for evaluating stent expansion in a stented blood vessel. The system includes one or more memory devices; and a computing device in communication with the memory devices, wherein the memory devices include instructions executable by the computing device to cause the computing device to perform the following steps: storing a first set of blood vessel image data in an electronic memory device in electronic communication with a first imaging system, generating the first set of blood vessel image data by scanning the blood vessel using the first imaging system; using one or more software modules to detect stent struts along a segment of the stented blood vessel; generating a first representation of the segment of the blood vessel, which indicates a level of stent expansion; using the detected stent struts to determine a first end of the stent and a second end of the stent; defining a first offset distance (D1) from the first end of the stent and a second offset distance (D2) from the second end of the stent; generating a second representation of the segment of the blood vessel using D1 and D2 in combination with a tapered profile of the segment; and assessing a level of target stent expansion along the segment of the blood vessel by comparing a first value associated with the first representation and a second value associated with the second representation at different locations along the segment.

[0021] In one embodiment, the first value is a first area or a first diameter, wherein the second value is a second area or a second diameter. In one embodiment, the system is one or a combination of an optical coherence tomography system, an angiography system, an ultrasound system, an x-ray system, a CT scanning system, an optical imaging system, a pressure sensing system, a flow sensing system, and a tomographic imaging system.

[0022] The OCT data can be used to generate 2-D views (e.g., cross-sectional and longitudinal views of a vessel) before or after a procedure associated with initial stent placement or correction stenting. The OCT data obtained using a data collection probe and various data processing software modules can be used to identify, characterize, and visualize a stent and / or one or more characteristics associated with the stent and / or lumen in which the stent is disposed.

[0023] In one embodiment, one or more outputs are visual depictions of the target stent contour overlapped with one or more regions of the vessel lumen contour. In one embodiment, one or more outputs are comparative measures of changes in measured or calculated parameters relative to segments of the vessel. In one embodiment, the parameter is selected from the group consisting of fractional flow reserve, flow velocity, vascular resistance ratio, virtual fractional flow reserve, simulated fractional flow reserve, measured fractional flow reserve, and pressure measurement.

[0024] In one embodiment, the method includes generating a vessel lumen contour using one or more computing devices after placing a stent in the vessel, including generating a representation of a segment of the vessel using a second set of intravascular data obtained relative to the vessel. In one embodiment, the first set of intravascular data is obtained during a first optical coherence tomography session. In one embodiment, the second set of intravascular data is obtained during a second optical coherence tomography session.

[0025] One or more devices may display one or more user interfaces and intravascular data or other information derived from such data. Intravascular data may be obtained using an IVUS or OCT-based data collection system and probe or other imaging modality. The method may be implemented using one or more computing devices and memory storage that receive intravascular data and user input via a graphical user interface (GUI) and include one or more image processing and frame selection software components. The computing device may be a microprocessor, an ASIC, or other processor suitable for use with an intravascular imaging system.

[0026] Although the present invention relates to different aspects and embodiments, it should be understood that the different aspects and embodiments disclosed herein can be appropriately integrated as a whole or in part. Therefore, each embodiment disclosed herein can be appropriately incorporated into a given implementation to varying degrees in each aspect. In addition, various software-based tools for solving medical imaging problems and other related challenges and problems and the aforementioned parts can be used without restriction in medical applications and other applications for displaying information related to stents, blood vessels and their two-dimensional views and three-dimensional views. Other features and advantages of the disclosed embodiments will become apparent through the following description and accompanying drawings.

[0027] Although the present disclosure relates to various aspects and embodiments and other features as described and depicted herein, it should be understood that each of the foregoing disclosed herein may be appropriately integrated as a whole or in part. Therefore, each of the embodiments disclosed herein may be appropriately incorporated into a given implementation to varying degrees in each aspect. In addition, the various stent expansion diagnostic tools described herein may be used with various imaging modalities.

[0028] Other features and advantages of the disclosed embodiments will be apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] This application contains at least one drawing executed in color. Copies of this patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0030] The drawings are not necessarily drawn to scale, emphasis instead generally being placed upon the exemplary principles. The drawings are to be considered illustrative in all respects and are not intended to be limiting of the disclosure, the scope of which is defined solely by the claims.

[0031] Figure 1A A schematic diagram of an imaging and data collection system suitable for imaging arteries, stents, and other cardiovascular system components is shown in accordance with an illustrative embodiment of the present disclosure.

[0032] Figure 1B A schematic diagram of an imaging and data collection system suitable for imaging arteries, stents, and other cardiovascular system components and including multiple displays is shown in accordance with an illustrative embodiment of the present disclosure.

[0033] Figure 2A is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent dilatation analysis results associated with co-registered angiography data, contour views, and other intravascular imaging views.

[0034] Figure 2B is a graphical user interface that displays stent expansion analysis results associated with a contour view according to an illustrative embodiment of the present disclosure.

[0035] Figure 3 is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent dilatation analysis results associated with a contour view and stent struts detected in another artery view.

[0036] Figure 4A and Figure 4Bis a schematic representation of a blood vessel including one or more side branches as shown suitable for generating a lumen contour model suitable for analyzing stent expansion according to an illustrative embodiment of the present disclosure.

[0037] Figure 5A is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent dilatation analysis results associated with co-registered angiography data, contour views, arterial measurements, and other intravascular imaging views.

[0038] Figure 5B is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent expansion analysis results and details regarding balloon sizes suitable for adjusting stent expansion levels.

[0039] Fig. 6A and Figure 6B is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent dilatation analysis results relative to stent struts detected in a contour view and another artery view.

[0040] Figure 7 is a graphical user interface according to an illustrative embodiment of the present disclosure that displays stent dilatation analysis results relative to stent struts detected in a contour view and another artery view.

[0041] Figure 8 is a schematic diagram of a software-based image processing pipeline suitable for analyzing stent expansion and other artery-related parameters according to an illustrative embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] The present disclosure relates in part to systems and methods for solving the following technical problems: detecting an expanded stent and providing diagnostic information to support supplemental stent expansion and balloon selection in the context of a vascular imaging, analysis and diagnostic system. As a challenge related to stent placement and proper expansion, it is an important technical challenge to coordinate angiographic images with respect to one or more imaging modalities so that areas of under-expanded stents can be easily identified on an accelerated time scale. The use of co-registration and the generation of various lumen contours can be used to address this challenge.

[0043] If the stent is under-expanded, it can lead to vessel failure one year after initial treatment. Therefore, assessing stent expansion while the patient is in the catheterization lab immediately after stent placement, generating a representation of the stent relative to the artery in which it is placed and the corresponding angiographic view are technical solutions to the problem of achieving proper stent expansion. Also described is the use of a model to generate a proper / completely expanded lumen model to provide diagnostic guidance regarding stent expansion.

[0044] Properly expanding a stent in a blood vessel (e.g., a coronary artery) is a significant target outcome because it increases the likelihood that a constricted, stenotic region of the artery will be successfully expanded and remain expanded based on proper balloon selection and stent placement, while informing the end user using an imaging modality. Solving this technical problem mitigates adverse outcomes (e.g., bypass surgery or other procedures).

[0045] Figure 1A A system 5 is shown, which includes various data collection subsystems suitable for collecting data, or detecting characteristics of a subject 4, or sensing a condition of a subject 4, or otherwise diagnosing a subject 4. In one embodiment, the subject is placed on a suitable support 19 (e.g., a table, bed, and chair, or other suitable support). Typically, the subject 4 is a human or another animal with a specific region of interest 25.

[0046] The data collection system 5 includes a non-invasive imaging system, such as an MRI, x-ray, computer-assisted tomography, or other suitable non-invasive imaging technology. As shown as a non-limiting example of such a non-invasive imaging system, a vascular angiography system 21 suitable for generating a canine is shown. The vascular angiography system 21 may include a fluoroscopic system. The vascular angiography system 20 is configured to non-invasively image the subject 4 so that frames of vascular angiography data (usually in the form of frames of image data) are generated while performing a pullback process using the probe 30 so that blood vessels in a region 25 of the subject 4 are imaged using vascular angiography in one or more imaging techniques (e.g., OCT or IVUS).

[0047] In one embodiment, the angiography system 21 communicates with an angiography data storage and image management system 22, which may be implemented as a workstation or server. In one embodiment, data processing associated with the collected angiography signals is performed directly on the detector of the angiography system 21. Images from the system 20 are stored and managed by the angiography data storage and image management 22. Other imaging systems disclosed herein may replace or augment the system 21.

[0048] The present disclosure relates in part to software-based methods, systems, and apparatus suitable for evaluating and depicting information regarding a vessel, stent, or other vascular or other intravascular information of interest. Figure 2A , Figure 2B , Figure 3 , Figure 5A , Figure 5B , Fig. 6A , Figure 6B and Figure 7Various user interface views are shown as follows: these user interface views show details related to the relative positions of stent expansion, vessel representation, lumen contours of stent endpoints (partially expanded lumen and fully expanded lumen) in both angiography and other imaging modalities (such as OCT). In particular, these systems and methods are related to technical solutions to the following technical problems: detecting and mitigating stent under-expansion in general, with particular emphasis on using guided imaging / diagnostic systems to expand stents. Imaging data and data derived therefrom (such as vessel representation) are generated and displayed as part of a user interface to quickly provide diagnostic information. These can take the form of different lumen contours and ratios of values ​​(such as area, diameter or other geometric values) at corresponding locations along their length.

[0049] Figure 1A The system includes various components for imaging one or more arteries and / or components of the cardiovascular system using one or more of CT scanning, ultrasound, IVUS, x-ray-based imaging modalities, magnetic resonance imaging, optical coherence tomography, infrared, laser-based imaging, and other imaging modalities for intravascular and extravascular imaging. In one embodiment, the system server 50 or workstation 85 handles the functions of system 22. In one embodiment, the entire system 5 generates electromagnetic radiation, such as x-rays. System 22 also receives this radiation after it passes through subject 4. In turn, data processing system 22 uses signals from angiography system 21 to image one or more regions of subject 4 (including region 25).

[0050] As shown in this particular example, the region of interest 25 is a subset of a blood vessel or peripheral vascular system (e.g., a particular blood vessel). The subset can be imaged using OCT, ultrasound, or one of the other imaging modalities disclosed herein, alone or in combination. In one embodiment, the region of interest can include a stent. The stent can be imaged at different time points (e.g., after deployment, and after supplemental stent expansion).

[0051] A catheter-based data collection probe 30 is introduced into a subject 4 and positioned within the lumen of a particular blood vessel, such as, for example, a coronary artery. The probe or other device including a balloon may also be used to increase the level of stent expansion in response to detecting an under-expanded stent using one or more imaging modalities.

[0052] The probe 30 can be various types of data collection probes, such as, for example, an OCT probe, an FFR probe, an IVUS probe, a probe combination feature of two or more of the aforementioned features, and other probes suitable for intravascular imaging. In one embodiment, the balloon delivery device is moved along a guide wire (for the imaging probe disclosed herein). In one embodiment, the probe 30 generally includes a probe tip, one or more radiopaque markers, an optical fiber, and a torque line. In addition, the probe tip includes one or more data collection subsystems, such as a beam guide, an acoustic beam guide, a pressure detector sensor, other transducers or detectors, and combinations of the foregoing.

[0053] For probes that include a beam guide, the optical fiber 33 is in optical communication with the probe having the beam guide. The torque line defines a hole in which the optical fiber is disposed. Figure 1A , the optical fiber 33 is shown without a torque line around it. In addition, the probe 30 also includes a sheath, for example, a polymer sheath (not shown) that forms part of a catheter. The optical fiber 33 (which in the context of an OCT system is part of the sample arm of the interferometer) is optically coupled to a patient interface unit (PIU) 35 as shown.

[0054] The patient interface unit 35 includes a probe connector that is suitable for receiving one end of the probe 30 and optically coupling with it. Typically, the data collection probe 30 is disposable. The PIU 35 includes appropriate connectors and components based on the type of data collection probe used. For example, a combination of OCT and IVUS data collection probes requires an OCT and IVUS PIU. The PIU 35 also typically includes a motor that is suitable for pulling back the torque line, sheath, and optical fiber 33 disposed therein as part of the pullback process. In addition to being pulled back, the probe tip is also typically rotated by the PIU 35. In this way, the blood vessels of the subject 4 can be imaged longitudinally or via a cross-section. The probe 30 can also be used to measure specific parameters (such as blood flow reserve fraction (FFR) or other pressure measurements).

[0055] In turn, the PIU 35 is connected to one or more intravascular data collection systems 42. The intravascular data collection system 42 can be an OCT system, an IVUS system, another imaging system, and a combination of the foregoing systems. For example, in the case where the probe 30 is an OCT probe, the system 42 may include a sample arm of an interferometer, a reference arm of an interferometer, a photodiode, a control system, and a patient interface unit. Similarly, as another example, in the case of an IVUS system, the intravascular data collection system 42 may include an ultrasound signal generation and processing circuit, a noise filter, a rotatable joint, a motor, and an interface unit. In one embodiment, the data collection system 42 and the angiography system 21 have a shared clock or other timing signal configured to synchronize the angiography video frame timestamp and the OCT image frame timestamp.

[0056] Various extravascular imaging systems (e.g., angiography systems) can image a given region of interest (e.g., a stent in various states of expansion). The extravascular imaging data can be co-registered with the intravascular imaging data. Figure 1B The various displays shown in are used to display the output of the intravascular imaging modality and the output of the extravascular imaging modality regarding a patient in the catheterization laboratory.

[0057] Apart from Figure 1A In addition to the invasive image data collection systems and devices and non-invasive image data collection systems and devices of the subject, various other types of data can be collected about the region 25 of the subject and other parameters of interest of the subject. For example, the data collection probe 30 may include one or more pressure sensors (e.g., such as a pressure wire). The pressure wire can be used without the addition of an OCT component or an ultrasound component. Pressure readings can be obtained along a segment of a blood vessel in the region 25 of the subject 4.

[0058] Such readings may be relayed by a wired connection or via a wireless connection. As shown in the fractional flow reserve FFR data collection system, the wireless transceiver 48 is configured to receive pressure readings from the probe 30 and transmit them to the system or to further locations along the vessel being measured to generate an FFR measurement. One or more displays 82, 83 may also be used to display angiographic frame data, OCT frames, user interfaces for OCT data and angiographic data, and other controls and features of interest.

[0059] Intravascular image data (e.g., frames of intravascular data generated using the data collection probe 30) can be routed to a data collection processing system 42, which is coupled to the probe via the PIU 35. Non-invasive image data generated using the angiography system 22 can be transmitted to, stored in, and processed by one or more servers or workstations (e.g., the co-registration server 50 workstation 85). In various embodiments, a video frame grabber device 55 (e.g., a computer board configured to acquire angiography image data from the system 22) can be used.

[0060] In one embodiment, the server 50 includes one or more co-registration software modules 67, which are stored in the memory 70 and executed by the processor 80. The server 50 may include other typical components for a processor-based computing server. Alternatively, more databases (such as database 90) may be configured to be stored in the memory 70. Figure 1A One or more system devices or components shown in receive the generated image data, the subject's parameters, and other information generated, received, or transmitted to the database 90 by the database 90. Although the database 90 is shown as being connected to the server 50 and stored in the memory of the workstation 85, this is merely an exemplary configuration. For example, the software module 67 may be run on the processor of the workstation 85, and the database 90 may be located in the memory of the server 50. As an example, a device or system for running various software modules is provided. In various combinations, the hardware and software described herein can be used to obtain frames of image data, process such image data, and register such image data.

[0061] As otherwise noted herein, software modules 67 may include software (e.g., pre-processing software, transforms, matrices), and other software-based components for processing image data or responding to patient triggers to facilitate co-registration of different types of image data by other software-based components 67 or otherwise perform such co-registration. Modules may include lumen detection using scanline-based or image-based methods, stent detection using scanline-based or image-based methods, indicator generation, stent expansion assessment and evaluation, stent landing zone detection and indication of deployed stents; angiography and intravascular imaging co-registration, and other modules supported and programmed to perform the methods disclosed herein.

[0062] The database 90 may be configured to receive and store angiography image data 92, such as image data generated by the angiography system 21 and obtained by the frame grabber 55 server 50. The database 90 may be configured to receive and store OCT image data 95, such as image data generated by the OCT system 42 and obtained by the frame grabber 55 server 50.

[0063] In addition, subject 4 may be electrically coupled to one or more monitors (e.g., such as monitor 49) via one or more electrodes. Monitor 49 may include, but is not limited to, an electrocardiogram monitor configured to generate data related to cardiac function and to show various states of the subject, such as systole and diastole. Knowing the cardiac phase may be used to assist in tracking the vascular centerline, since the geometry of the heart (including the coronary arteries) is generally the same in a particular cardiac phase (even over different cardiac cycles).

[0064] The use of directional arrows or the lack of such arrows in a given figure is not intended to limit or require the direction in which information can flow. For a given connector, for example, Figure 1A The arrows and lines shown in the figure are shown as connecting elements, for example, for a given embodiment, information can flow in one or more directions or only in one direction as appropriate. The connection can include various suitable data transmission connections, such as optical, wire, power, wireless or electrical connections.

[0065] One or more software modules may be used to process data from an angiography system (e.g. Figure 1A Frames of angiographic data received by the system 22 shown in FIG. Various software modules may be used in given embodiments of the present disclosure, which may include but are not limited to software, components thereof, or one or more steps of a software-based or processor-implemented method.

[0066] Figure 1A and Figure 1BThe system is suitable for displaying intravascular image data and extravascular image data. In particular, the system is advantageous for stent planning and assessment of stent expansion and assessment of target stent expansion. In one embodiment, the stent expansion threshold can be provided by a diagnostic system (e.g., OCT, IVUS, or other image data collection system), or such a threshold can be adjusted and set by an end user via a user interface. In one embodiment, the range of the stent expansion threshold for identifying an area where the stent is under-expanded is about 80% to about 90%. Therefore, if the stent is expanded to a level of 48% at a first position along its length, the stent is identified or indicated by a visual cue or mark, and if in another area, the stent is expanded to a level at or above the threshold, the stent is identified by another visual cue or mark.

[0067] Figure 1B The imaging and data collection system (eg Figure 1A A catheterization laboratory is established with components of a system (system) for performing OCT, FFR, IVUS, angiography, CT scan or other types of imaging, measurement and assessment on one or more arteries of a patient. A user can interact with the data collection system through the various displays shown, or otherwise access and display stored image data. An exemplary user interface showing intravascular imaging data and stent expansion data co-registered with angiography data is shown. A support member 115 (e.g., an accessory) is laid on a table, bed or other support 120. In one embodiment, the support member 115 can be part of the support 120, and the controller can be directly attached to the support 120.

[0068] In one embodiment, the controller may include any suitable input device and may be used to navigate user interface screens and parameters (e.g., target stent expansion values ​​and other stent expansion thresholds). In one embodiment, the controller includes an attachment device 60, such as a clamp for mounting as shown. The controller may be used to display and navigate a graphical user interface displayed on one or more monitors or displays 123. In one embodiment, the monitors may be mounted on a ceiling suspension. A graphical user interface 127 may be displayed on a given monitor. Two exemplary graphical user interfaces 127a, 127b are shown in FIG. Figure 1B , including stent expansion and co-registered intravascular data, such as OCT data and angiography data.

[0069] In one embodiment, the controller has a feature set that is configured to map to commands and menus available to a user as part of a graphical user interface 127. An angiography system or other imaging system disclosed herein 125 can be positioned relative to the support 120 to obtain an x-ray of a patient while another data collection process (e.g., an OCT process) is in progress. The graphical user interface 127 can display such OCT, angiography, FFR, IVUS, and other data of interest to the user. The controller is configured to control the interface 127 and navigate the menus and image display features that it presents to the user. Co-registering the angiography data with the intravascular imaging supports the assessment of the level of stent expansion.

[0070] In one embodiment, a first geometric value for simulating the far end of a healthy blood vessel and a second geometric value for the proximal end of a healthy blood vessel are used to effectively simulate a healthy lumen profile. In one embodiment, these geometric values ​​are determined at a position offset or shifted relative to the profile of the stented blood vessel. These shift values ​​or offset values ​​are shown as D1 and D2 in each figure. The geometric value can be a cross-sectional area, a diameter, a chord, a flow value, or other values ​​suitable for interpolating a healthy lumen profile. Then, by comparing the geometric values ​​of each corresponding profile in proportion, the simulated healthy lumen profile can be compared with the stent profile.

[0071] The present disclosure describes systems and methods for delineating regions of stent under-expansion and at target expansion levels relative to a representation of a vessel generated using intravascular data to facilitate targeted balloon placement and sizing of a placed stent. Optical coherence tomography and other imaging modalities can be used to generate various vessel representations and to perform various image data processing techniques to detect and / or visualize the lumen L, stent struts SS, side branches SB, and other components as shown and described herein.

[0072] One or more stent expansion measures may be used. In one embodiment, the stent expansion measure may be adjustable by an end user. Thus, a physician may set a stent expansion threshold to a percentage of stent expansion, such as 90% or another percentage. Figure 2A Such a threshold for depicting whether a stent has expanded to the 90% level is shown in the figure by legend 231, which shows the area of ​​underexpansion along the lumen contour of the stented vessel based on the threshold, the red area, also shown as area 220. In turn, the area along the length of the stent in which it has expanded to 90% or above the threshold is shown in white, or as area 225. The minimum stent area (MSA) in the vessel is also shown in each figure by cursor 227 and the MSA.

[0073] If stent under-expansion has been detected in one or more regions of the vessel as part of the user interface, a marker 220 (e.g., red or another visual cue) can be used to show the physician the regions where the stent has expanded to the target expansion level (90% in this example), or above that expansion level: region 225. In this way, the end user can choose to select a balloon based on the appropriate diameter to achieve the target expansion level, and can reference angiographic images and other imaging data to position the selected balloon and increase expansion of one or more stents in the regions where they are under-expanded.

[0074] Figure 5B An updated view of a vessel representation is shown showing a white area 225 above the N% expansion threshold, and a shaded area 220 below the N% threshold. A user interface component showing balloons B1, B2, B3, and B4 with various diameters can be used to overlay them on the diagram, or measurements can be performed relative to the various representations to select an appropriate balloon diameter. Balloon sizes are provided based on the level of stent expansion (which is required based on a target expansion threshold or target). In one embodiment, the balloon size is calculated based on the unexpanded diameter of the artery at one or more locations. In one embodiment, the balloon is a movable graphical element that can be user-selectable and placed relative to a given artery view described herein. Exemplary balloon B4 is shown as being placed in the artery at an area 230 that overlaps the MSA. This area is a location where expansion is warranted based on stent expansion analysis and thresholds.

[0075] Regions of stents shown as appropriately expanded (e.g., 90% level, or above 90% level) can maintain their current expansion levels while allowing the end user to address under-expanded regions. Selecting an appropriate balloon diameter allows the user to quickly return to the patient, position the stent and under-expanded regions on angiography, and use the lumen contour view shown herein as a guide to position the balloon in one or more regions of under-expanded regions, and further expand the stent before concluding the overall session in the catheterization laboratory and releasing the patient. Using these various technical diagnostic tools as well as lumen contours and expansion ratios, stent placement that may lead to the need for bypass can be corrected, and the likelihood of successful patient outcomes is increased.

[0076] To further address the issue of properly expanding the stent, a co-registration was performed between the stent position and expansion level and the angiographic system. Figure 2AAn overall user interface generated using imaging data from two or more imaging modalities is shown. An angiographic image is shown in the angiography interface panel 205, which shows reference positions R1 and R2, which are generated after performing stent detection on a second imaging modality (e.g., OCT, ultrasound, or other). The area of ​​the under-expanded stent 220 is shown in the angiography view 205 and the lumen contour view 211. A cross-section of the vessel at the cutting plane (CP) is shown in the interface panel 205. The average diameter value is shown in the panel as the lumen L and the stent strut shadow. The cutting plane is divided into two parts labeled B and Y, which can be color-coded as a blue line and a yellow line.

[0077] Figure 2A An exemplary output of diagnostic results for guiding an end user after a stent has been placed in a blood vessel is shown. The various diagnostic results are organized in a graphical user interface 200. As shown, various panels or areas of the graphical user interface 200 are shown. These include an upper left panel 205 displaying angiographic image data that is co-registered with one or more related images or vessel representations. In addition to Figure 2A In addition to the common interface display shown in , an auxiliary display may also be used to display the angiography diagnostic interface 205 .

[0078] The longitudinal view is shown as part of interface panel 215, which also shows the various stent struts SS in the longitudinal view of the imaged vessel. Co-registration has been performed between the angiographic image and the lumen contour view 211. The lumen contour view includes a highlighted HL area designed to attract the user's attention. In this portion of the contour, the cutting plane line CP or 240 corresponds to line segments B and Y, which are shown together in other views of the intravascular image shown in panels 209 and 215. A dark lumen L is shown in the middle of the lumen contour view. The stents are encoded using visual cues such as those shown in areas 220 and 225. These correspond to legend 231, which is used to show the stents for under-expansion and expansion above a target expansion threshold (in Figure 2A The distal direction is on the left and the proximal direction is on the right.

[0079] The minimum stent area MSA or 245 is shown and is also tracked using a vertical line cursor 227. The MSA is the narrowest area of ​​the stent. In addition, the area 220 clearly extends into the vessel wall representation that constrains the lumen L and is shown as narrowing relative to the vessel wall representation. In one embodiment, the MSA is identified as an area for balloon deployment to adjust stent expansion after initial deployment. These areas 220 show areas where the stent has not been properly expanded to reach the 90% expansion threshold. The area 225 shown to the left of the cutting plane 240 is expanded at or above the 90% threshold. These representations allow the end user to return to the patient and place a balloon on the delivery catheter while the guidewire is still in the vessel and use real-time angiography and reference. Figure 2B 225 to properly place a balloon with the correct diameter to expand the target area 225. These various tools solve the complex technical problem of properly expanding a stent. The process reduces the overall time a patient spends in the catheterization lab by speeding up subsequent stent expansion if the area requires it.

[0080] These systems, devices and methods are implemented when a subject is evaluated for the first time using a diagnostic method (e.g., one or more cardiac imaging modalities. These imaging modalities may include, but are not limited to, OCT, IVUS, computer-assisted tomography, MRI, angiography, x-ray, pressure data-based models of cardiac and / or vascular operation and status.

[0081] The present disclosure relates in part to systems, methods and devices for evaluating a stent placed in a blood vessel relative to one or more planned stages and profiles obtained about a blood vessel or stent. Profiles and information related to a blood vessel or stent can be obtained using an intravascular data collection system and associated probes (e.g., optical coherence tomography (OCT), or intravascular ultrasound (IVUS), or other intravascular data collection modalities). In addition, the present disclosure provides an automated method for a user (e.g., a clinician or other person) to assess whether a stent placed in a blood vessel has expanded to an appropriate level, such as a substantially optimal level or other appropriateness measure. In one embodiment, these measures can be specified by a user.

[0082] The present disclosure relates in part to a method of evaluating stent placement in a blood vessel. The method includes using one or more computing devices to generate a representation of a segment of a blood vessel using a first set of intravascular data obtained about a blood vessel in which a stent has been positioned. This is shown in various lumen contour views 211, 211b, 211c, 211d, 211e (see Figure 2A , Figure 2B , Figure 5A , Figure 5B , Fig. 6A and Figure 6B ), in which a stent is shown, and regions of proper expansion and under-expansion are shown relative to an expansion threshold of N%. Fig. 6A and Figure 6B User interfaces 320, 321 are shown including detected stent struts 325 in the bottom panel and lumen contour views 211d and 221e showing MSA, EXP, and regions of dilation with a threshold of about 90% (see legend 231). Regions 220 that would benefit from further dilation are shown in each respective lumen contour view. These views can also be co-registered with an angiography system.

[0083] As part of an overall system and method, using a system (e.g., the system disclosed herein, including Figure 1A , Figure 1B and Figure 8 ) to perform various imaging processing techniques. Image processing steps may include lumen boundary detection, corresponding to the boundary between the lumen L and the vessel wall (which constrains it), stent detection, side branch detection, and others. Lumen detection informs stent detection because it gives relative positions to which stents will exist in the image.

[0084] The lumen detection software may include one or more steps. For example, in one embodiment, to perform lumen detection, a filter or other image processing device may be applied to a two-dimensional image to detect edges in the image that indicate lumen boundaries. In another embodiment, a scan line based method is used. During one or more pullbacks, optical or ultrasound signals are collected as scan lines about a blood vessel and one or more stents disposed in the lumen of the blood vessel. In one embodiment, lumen detection software executing a computing device uses the computing device to generate one or more images from a collection of scan lines. Lumen detection may also be performed using other image data sets from other imaging systems.

[0085] Once the stent struts are detected, they can be displayed as shown in the various images. After stent detection, and as part of the generated lumen contour views, offset distances D1 and D2 are generated. These can be shifts of distance to the left and right (proximal and distal), or vice versa. Figure 2A In FIG. 5 , these references are shown by lines R1 and R2 .

[0086] exist Figure 2BIn FIG. 1 , R1 and R2 are shown as dashed lines. The end points of the stent are shown by vertical lines EP1 and EP2, which are the first and second end points of the stent. These can be automatically detected once the stent detection software module has detected the stent. The stent end points are used to generate reference lines R1 and R2, which are automatically generated lines that are a certain distance away from the lumen. These distances are D1 and D2, as shown in FIG. Figure 2B The double-headed arrow in FIG. 1 is also shown as the area of ​​the lumen at these offset distances. The further side area at offset distance D1 is shown as 8.5 mm. 2 , and another larger proximal area of ​​offset distance D2 is shown as 11.23 mm 2 . The lengths of D1 and D2 are typically equal, but may vary. They are typically a relatively short distance from the stent endpoints and are in the range of about 0.1 mm to about 1 mm. Values ​​of, for example, about 0.4 mm or about 0.5 mm are desired, but other offset distances may be selected. The first reference line R1 may be a distal reference and the second reference line R2 may be a proximal reference, or vice versa.

[0087] The offset distances D1 and D2 are used to move a distance away from the end points of the stent because the lumen area, distance or other geometric values ​​at these points are used to generate another lumen profile having a tapered profile 290, such as 211a (see Figure 3 ) and 211f (see Figure 7 ). Stent placement can be considered a proxy for healthy areas of the vessel. The selection of the stent endpoints themselves may have various errors due to the viewing plane, the output of the stent detection software module, and reflections from the stent struts at the endpoints, blooming effects, and other factors.

[0088] Thus, selecting the position offsets D1 and D2 from the stent endpoints allows geometric values ​​of the lumen profile (e.g., the area or diameter of the lumen to be selected at the two points). These values ​​can be used to interpolate a tapered profile 290, which can be used as a fully expanded lumen profile. Thus, by interpolating such a lumen profile 290 (which corresponds to the result if no stent is needed and there is no stenosis between reference lines R1 and R2), an lumen profile can be generated using image data processing software. A lumen profile corresponding to a fully expanded lumen spanning the same area as the stent allows the expansion ratio to be calculated at each position along the stented area.

[0089] Specifically, the ratio of the cross-sectional area, or diameter, or another value from the stented lumen profile can be compared to the corresponding cross-sectional area, or diameter, or another value from the interpolated, fully expanded lumen profile to generate a stent expansion threshold value N%. Figure 7In the example, the dashed tapered contour shows what the fully expanded lumen would look like if the tissue was not stenotic. This can be compared to the area or diameter values ​​obtained from the lumen contour generated after stent detection to show the amount of expansion at different points. In one embodiment, the minimum expansion frame 48% (EXP) is also automatically called, as shown in FIG. Figure 2B , Figure 3 and Figure 7 This frame indicates where the stent is at least expanded. As a result, this can be used as a target for further expansion with a balloon. Co-registration with angiography can further help guide such balloon placement.

[0090] In one embodiment, the method includes generating and displaying the expansion level based on an expansion ratio of N% obtained using a first representation of the vessel (based on stent expansion) and an interpolated second representation of the expansion (generated in the absence of the stent). Simulating the healthy lumen contour representation facilitates generating a metric to assess the level of stent expansion and display when the metric is met (expansion above N%) or not met (failure to expand sufficiently to reach N% expansion at position X). These representations can be obtained using intravascular data or other imaging data. The foregoing steps are performed so that the representation is co-registered with one or more angiographic images of the vessel. In view of this diagnostic representation of the imaging data, the user can then place a stent in a stenotic area identified as a target for stent placement.

[0091] Additionally, after one or more stents have been placed in the artery, a second imaging session is performed, such as performing a second intravascular pullback during angiography. A second representation of the artery can be generated, and the repositioned or expanded one or more stents can be assessed.

[0092] The present disclosure relates in part to a processor-based stent placement evaluator or evaluation system. The system or evaluator includes one or more memory devices; and a computing device in communication with the memory device, wherein the memory device includes instructions that are executable by the computing device so that after performing stent detection, the computing device generates one or more representations of the blood vessel so that the level of stent expansion achieved relative to a threshold or other metric can be displayed by appropriate markings or graphical user interface elements, thereby quickly presenting information to the end user to reduce the time spent by the subject in the catheterization laboratory. The user can use interface features (e.g., such as Figure 5A In addition, once the diagnostic information is available to the end user, they can select the appropriate balloon based on the required diameter to further expand the stent and thereby increase blood flow in the stenotic area and avoid subsequent procedures.

[0093] Figure 5A Various user interface panels are shown in FIG. Various measurements can be determined (by using Figure 8 ) and displayed as shown in the measurement interface panel 267. For a given lumen profile, the area, mean diameter, radius, minimum diameter, and maximum diameter can be determined and displayed. The various regions of the detected stent are shown in the highlighted area of ​​the middle contour view 211b, where the lumen L and R1 and R2 are marked. In one embodiment, the area along the length of the stent (in which the stent has been expanded to 90% or above a threshold) is displayed in white, or as area 225. The minimum stent area (MSA) in the vessel is also shown by the cursor 227 and MSA in each figure. The expansion of the stent at the MSA is shown to be approximately 48%. The reference to white and red in the accompanying drawings is merely an example of distinguishing colors or markings. Other markings can be used in a given embodiment.

[0094] If stent under-expansion has been detected in one or more areas of the vessel that are part of the user interface, marking 220 (e.g., red or another visual cue) can be used to show the physician areas where the stent has expanded to a target expansion level (90% in this example), or areas above that expansion level, area 225.

[0095] The present disclosure relates in part to operations and methods performed on diagnostic data (e.g., intravascular data generated using a diagnostic system). Examples of such systems may include optical coherence tomography, intravascular ultrasound imaging, and other intravascular data collection systems. The methods and systems described herein may use various steps and processing stages to perform one or more imaging pullbacks to collect intravascular data. Each or a subset of one or more pullback imaging sessions may also be imaged in parallel using an angiography system.

[0096] The present disclosure relates to various methods, systems and devices related to stent detection and stent representation as part of a diagnostic and process information system suitable for assisting stent planning. The present disclosure is partially included in the patent application entitled "STENT AND VESSEL VISUALIZATION AND DIAGNOSTIC SYSTEMS, DEVICES, AND METHODS", filed on July 24, 2015, and U.S. Patent Application Publication No. 20160022208, and in the patent application entitled "METHOD AND APPARATUS FOR AUTOMATED DETERMINATION OF ALUMEN CONTOUR OF A STENTED BLOOD VESSEL", filed on March 12, 2013, and U.S. Patent Application Publication No. 20150297373, the entire disclosure of each of which is incorporated herein by reference.

[0097] The present disclosure relates in part to computer-based methods, apparatus, and systems adapted to image a vessel using one or more imaging modalities, co-register the imaging modalities, and represent the imaged vessel with a detected stent shown relative thereto. Under-expansion of the stent and expansion levels within a predetermined target expansion level are also shown. Various systems and imaging modalities can be used to solve the problem of how to properly expand a stent as disclosed herein. This document (including regarding Figure 1A and Figure 1B ) discusses additional details about an exemplary system. The following output of the system provides useful information: The output description is used to provide diagnostic guidance to address technical challenges of stent expansion.

[0098] A two-dimensional view of a blood vessel with a labeled lumen L is shown in the graphical user interface panel 209. The line segments labeled B or Y correspond to the segments in the bottom panel 215. A lumen outline panel 211 is shown in the middle of the entire interface 200. The lumen outline view has two central reference frames R1 and R2 that combine the portion of the blood vessel where the stent has been detected and is displayed in the shown representation.

[0099] Figure 2B A zoomed in view of the lumen profile 211 graphical user interface is shown, with the end points of the stent shown by vertical dashed lines EP1 and EP2. These end points of the stent are determined using a subset of the detected stent struts that span the segment of the vessel.

[0100] In one embodiment, an offset distance is used to shift away from the edge of the first stent strut detected in a frame of image data and the edge of the last stent strut detected in a frame of image data. If the end stent struts throw off geometric values ​​that should be used to model the healthy lumen contour, the tapered contour interpolated using the first reference frame and the second reference frame may be modeled incorrectly. Therefore, an offset that is far shifted or a position along the vessel representation that is moved a distance away from the end of the stent is selected. These distances are in Figure 2B These can be used to generate lumen profile 211a, which shows a tapered profile 290 that can be used as a basis for comparison with the lumen profiles of stents described and depicted herein.

[0101] When placing a stent, it is advantageous to select a landing zone of normal / healthy tissue, which facilitates interpolation of a simulation of a healthy fully dilated vessel as a baseline comparator for the lumen contour generated based on how dilated / under-dilated the stent actually is. In one embodiment, a cursor or other on-screen user interface element is placed at both ends of the stented area, such as reference points R1 and R2. The cross-sectional area or another vessel parameter is automatically displayed relative to each end of the stented area. The D1 and D2 offsets can be calculated by shifting away from the stent endpoints at R1, R2 / EP1, EP2.

[0102] Figure 4A and Figure 4B A schematic representation of a vessel is shown including one or more side branches as shown suitable for generating a lumen contour model / representation of a healthy version of the imaged vessel for comparison with a recent stented and imaged vessel. Various methods may be used to interpolate the tapered contour to generate a basis for comparison with the actual level of stent expansion performed and measured after stent detection is complete.

[0103] The imaged vessel (e.g., coronary artery) tapers from proximal to distal, and the size of the side branches in between affects the amount of taper. As part of the taper, the vessel diameter decreases when moving from proximal to distal. The step-like decrease in diameter when passing through the side branches is proportional to the diameter of the intermediate side branches. Figure 4A shows the tapering of the middle side branch SB, where D prox is the diameter of the proximal vessel, and D dist is the diameter of the distal reference, B is the diameter of the middle side branch, and the scaling exponent (exp) ranges over various values ​​according to the model and related equations disclosed herein, and various values ​​of the model and related equations disclosed herein.

[0104] The vessel tapering profile or relationship for a single side branch can be used to calculate the ideal tapering in the stented segment using the distal and proximal reference frames and multiple intermediate side branches. Figure 4B In FIG. 1 , the taper from the proximal segment to the distal segment and the two intermediate side branches are shown. The increment can be calculated using the vessel scaling law and To provide a continuous tapering reference from the proximal section to the distal section.

[0105] If there is Figure 4B If there are multiple intermediate side branches as shown, the increment due to each side branch needs to be calculated, and the intermediate reference diameter D can be calculated i The intermediate reference diameter will then allow for a continuous estimate of the taper from the proximal reference segment to the distal reference segment. Other interpolation techniques may also be used to generate the tapering profile. In one embodiment, the following relationship is used.

[0106]

[0107] The side branch location and diameter can be measured when the diameter of the distal and proximal reference frames are known. The unknown single increment needs to be calculated. and A generalized method for estimating the increment that can be used for any number of intermediate side branches is shown below:

[0108] The difference between the proximal and distal reference diameters is:

[0109]

[0110] d prox is the diameter of the proximal reference frame, and d dist is the diameter of the distal reference frame.

[0111]

[0112] and are the increment or step size from the distal reference to the proximal reference at the ith branch, where there are a total of N branches. The segment increment at each branch is proportional to the diameter of branch B raised to the scaling law exponent.

[0113]

[0114] The increment of the i-th branch to the i-th segment The contributions are:

[0115]

[0116] The diameter of the reference profile in segment i is calculated as:

[0117]

[0118] In various embodiments, a tapered reference profile / tapered profile 290 is shown on the lumen profile, for example in FIGS. Figure 7 Increments in tapering occur at each automatically detected side branch, as shown on the lumen outline. The proximal and distal frames are automatically positioned using the stent detection feature. Figure 3 Also shown is the location of the minimum dilation frame (EXP), and the dilation percentage at that frame and the MSA frame.

[0119] The adaptive ideal reference profile is calculated using the natural tapering of the vessel due to side branches. There is a mathematical relationship between the distal reference and the proximal reference of Equation 1 and the medial side branches.

[0120]

[0121] Where D prox is the diameter of the proximal vessel, and D dist is the diameter of the distal reference and B is the diameter of the intermediate side branches. In the case where no major side branches were detected between the distal and proximal references, the ideal lumen diameter at each location was calculated by using linear interpolation between the distal and proximal references.

[0122] In the case of multiple side branches, the ideal reference profile between the distal reference frame and the proximal reference frame tapers in a step-like manner at each side branch, with larger side branches contributing proportionally larger steps. This can be seen in the dashed line of the tapered profile 290.

[0123] If the distal reference frame and the proximal reference frame are in the same segment, the stent contour is a linear interpolation between the distal reference frame and the proximal reference frame. In one embodiment, a method for determining a target stent contour in response to one or more user-selected reference frames is as follows. The total number of side branches between the reference frames is input as N.

[0124] For example, if four (N=4) side branches between the farthest and closest frames of a segment are shown. The side branches are shown as SB in the figure, or as a visual cue as circles or dots, e.g. Figure 1AThe side branches in are located at the top of the lumen, and three are located at the bottom. exp=2.3 is a scaling exponent. In one embodiment, the exp value ranges from greater than or equal to about 2 to less than or equal to about 3. The exp value describes the tapering scalability of the segment between user-selected reference frames. In normal subjects, the exp value ranges from about 2.2 to about 2.7. In one embodiment, the exp value is about 7 / 3, or about 2.333. In other embodiments, exp is less than about 3.

[0125] The difference between the proximal and distal reference diameters is:

[0126]

[0127] d prox is the diameter of the proximal reference frame, and d dist is the diameter of the distal reference frame.

[0128]

[0129] is the increment of the bracket segment at the nth branch (to be calculated)

[0130] The segment increment at each branch is proportional to the diameter of the branch raised to the exponential of the scaling law.

[0131]

[0132] Diameter of the stent in segment n+1:

[0133]

[0134] The above segment diameters provide a delta measurement by which the boundaries of the upper and lower tapers of the target stent profile undergo a step-like change in quantity (e.g., delta measurement) as the tapered boundaries are generated across the vessel segment. This tapering, along with information about healthy regions in the vessel, can be used to interpolate a lumen profile representative of a healthy vessel—which can be achieved through appropriate stent expansion over the entire length of the stent.

[0135] After the stent has been placed, the stent detection algorithm locates the lumen area with the stent. The lumen profile in the stented area is compared with a second lumen profile, which is generated by interpolating between the first position and the second position of the blood vessel from the detected endpoint displacement distances D1 and D2 of the stent. The stent landing area (which corresponds to its corresponding endpoint) is associated with healthy tissue in the blood vessel. By displacing the endpoint displacement distances D1 and D2 relative to the detected stent, the diameter, area, chord, etc. of two healthy lumens can be selected. These two selected distances are used together with the tapered profile of the blood vessel and other blood vessel parameters and models to interpolate the tapered profile 290, which can be shown in one or more lumen profile views.

[0136] Any over-expansion or under-expansion can be determined by comparing two lumen contour views (measured and interpolated) or ratios, or other metrics based on geometric values ​​at the same location on each contour. For each point along the stent, a ratio of values ​​(e.g., diameter or area from an interpolated lumen contour view indicating the result from an ideal stent expansion)) can be generated relative to the corresponding area value or diameter value of the lumen contour generated using the detected stent struts. The contour generated from the detected stent struts represents the level of expansion obtained when a balloon is initially used to expand the stent positioned in a blood vessel. The stent is placed in a target landing zone. In one embodiment, based on the selection of these landing zones, correlation with these zones selected as healthy has been used as a measurable parameter to address the technical challenges of assessing stent expansion. These and other metrics can be used to generate tools for end users as part of stent expansion assessment and correction.

[0137] The systems and software-based methods described herein can process frames of optical coherence tomography data obtained relative to a blood vessel so that a stent disposed in the blood vessel can be evaluated or otherwise characterized. In one embodiment, each cross-sectional image can constitute a frame of OCT image data. For example, in one embodiment, such a stent is identified on a graphical user interface that shows a three-dimensional image or a two-dimensional image of a blood vessel generated using the collected image data.

[0138] The software modules and stented vessel expansion assessment and display features described herein may be implemented using a non-transitory computer readable storage medium. In one embodiment, the non-transitory computer readable storage medium stores a program that, when executed by a computing device, causes the computing device to perform methods for processing or otherwise manipulating intravascular image data and intravascular parameters. Each method may include one or more of the steps outlined herein.

[0139] The systems and software-based methods described herein can process frames of optical coherence tomography data obtained relative to a blood vessel so that a stent disposed in the blood vessel can be evaluated or otherwise characterized. In one embodiment, each cross-sectional image can constitute a frame of image data. For example, in one embodiment, such a stent is identified on a graphical user interface that shows a three-dimensional image or a two-dimensional image of a blood vessel generated using the collected image data.

[0140] The software modules and stented vessel dilatation assessment and display features described herein may be implemented using non-transitory computer-readable storage media. In one embodiment, a non-transitory computer-readable storage medium stores a program that, when executed by a computing device, causes the computing device to perform a method for processing or otherwise manipulating intravascular image data and intravascular parameters. Each method may include one or more of the steps outlined herein. In one embodiment, the stent dilatation threshold is in the range of about 90% to about 100%. In one embodiment, the stent dilatation threshold is in the range of about 80% to about 90%. In one embodiment, the stent dilatation threshold is in the range of about 85% to about 95%. In one embodiment, the stent dilatation threshold is in the range of about 75% to about 85%.

[0141] Non-Limiting Software Features and Examples for Enabling Stent Expansion Assessment and User Feedback

[0142] The present disclosure relates in part to computer-based methods, systems and devices for visualizing stents. In one embodiment, the present disclosure relates to methods for evaluating the expansion of a stented blood vessel and whether further expansion is needed, or whether the stent needs to be repositioned. These methods of evaluation may include displaying one or more views of the stent in various states (e.g., relative to the expansion state of the blood vessel), and comparing the imaged stent relative to one or more selected stent contours. In one embodiment, the method is performed automatically. The methods of the present disclosure may be implemented using software (e.g., stent contour analysis software), which may include stent planning software and lesion preparation software (or vice versa).

[0143] The stent to be placed can be selected using OCT, IVUS, angiography, or other detection data obtained relative to the unstented vessel segment and then compared with the stented vessel. The stented and unstented stages of the stent planning can then be displayed longitudinally or in a cross-sectional view as part of one or more graphical user interfaces (GUIs) as an expanded state or an unexpanded state. Such an interface can include one or more views of the vessel generated using distance measurements obtained using an OCT system, an IVUS system, an angiography system, or other data collection system.

[0144] A second pullback may be performed just after stent placement, enabling further expansion or repositioning or removal. These may result in saving valuable time and the need for follow-up procedures.

[0145] Figure 8 An exemplary image processing pipeline 350 is depicted in the figure for transforming the collected OCT data into two-dimensional and three-dimensional views of the vessel and stent, and comparing the contours relative to the stent deployment. The image data processing pipeline or any method described herein is stored in a memory and executed using one or more computing devices (e.g., processors, devices, or other integrated circuits). In one embodiment, the computing device 340 includes or accesses software modules or programs, such as a side branch detection module, a guide wire detection module, an inner cavity detection module, a stent deployment analysis software, a stent expansion analysis and display software (e.g., Figure 1A Software 67), and other software modules. The software modules or programs may include an image data processing pipeline or its component modules, and one or more graphical user interfaces (GUIs).

[0146] like Figure 8 As shown in , one or more displays 346 can be used to display the following information: for example, cross-sectional views and longitudinal views of a blood vessel generated using collected intravascular data and angiographic data, such as blood vessel segment views and contours shown and disclosed herein. These displays 346 can be arranged as follows Figure 1BAs shown. One or more graphical user interfaces (GUIs) may be used to display the information. In addition, the information may include, but is not limited to, cross-sectional scan data, longitudinal scans, lumen contours, VRR values, FFR values, stents, malpositioned areas, lumen boundaries, imprisoned side branches, and other images or representations of blood vessels or potential distance measurements obtained using the system 355 and the data collection probe. In one embodiment, the computing device 340 may also include software or programs 344, which may be stored in one or more memory devices and configured to identify target stent contours, lumen contours, and stent expansion values, as well as target and other vascular features, such as with text, arrows, color coding, highlights, outlines, or other human or machine-readable marks. The software module pipeline may include features for supporting and providing stent expansion analysis and display. Various marks may be applied via a mark application module 370 to emphasize and distinguish any one or all of the detected and generated arterial image data and the generated contour views and parameters related to the stent.

[0147] Once image data is acquired using a probe or other imaging system (e.g., an angiography system) for OCT or IVUS image data, it is stored in a memory; it can be processed to generate information (e.g., cross-sectional, longitudinal, and / or three-dimensional views of a vessel along the length of a pullback region, or a subset thereof). These views can be depicted as part of the user interface depicted in the various figures. Images of the vessel generated using distance measurements obtained from the OCT system provide information about the vessel and objects disposed therein.

[0148] As shown, the pipeline can receive post-stent deployment pullback data 352 (post-stent deployment pullback data 352 will appear after the initial pullback) to image the vessel. User selections can be received via the GUI, and the stent planning data can be transferred to the stent contour or stent deployment analysis software (e.g. Figure 1A67 in the pipeline). The guide wire 354, side branch detection 356, stent detection 358 and lumen detection module 360 ​​can operate on post-stent deployment pullback data (which can be collected by the scan line). The stent expansion analysis and display software 362 can perform various steps as described herein, for example, evaluating the detected stent relative to the detected lumen shape, calculating stent expansion, calculating MSA, measuring stent parameters, and showing the expansion level of the stent at different frames along the artery and other features and methods disclosed herein. In addition, the pipeline may include co-registration software that is used to co-register the angiographic data and the intravascular data to show the stent expansion data relative to the angiographic data. In one embodiment, data from two or more intravascular imaging pullback sessions are used to evaluate stent expansion, wherein the probe is pulled back through a portion of the artery.

[0149] The following description is intended to provide an overview of the device hardware and other operating components suitable for performing the method of the disclosure described herein. This description is not intended to limit the applicable environment or scope of the present disclosure. Similarly, the hardware and other operating components may be suitable as a part of the above-mentioned equipment. The present disclosure may be practiced with other system configurations (including personal computers, multiprocessor systems, microprocessor-based or programmable electronic devices, network PCs, minicomputers, mainframe computers, etc.). The present disclosure may also be practiced in a distributed computing environment, wherein tasks are performed by remote processing devices linked by a communication network (e.g., in different rooms of a catheterization laboratory or a tube laboratory).

[0150] Some portions of the detailed description are presented in the form of algorithms and symbolic representations of operations on data bits within a computer memory. Those skilled in the art of computers and software can use these algorithmic descriptions and representations. In one embodiment, an algorithm is here (and generally) considered to be a self-consistent sequence of operations leading to a desired result. The operations performed as methods or in other ways described herein are those requiring physical manipulations of physical quantities. Typically (but not necessarily), these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, transformed, compared, and otherwise manipulated.

[0151] Unless otherwise specifically stated from the following discussion, it should be understood that throughout the specification, the use of terms (for example, "processing" or "computing", "covering" or "searching", or "detecting", or "measuring", or "calculating", or "comparing", "generating", or "determining" or "displaying"), or Boolean logic, or other set-related operations, etc., refers to the actions and processes of a computer system or electronic device that manipulates and transforms data represented as physical (electronic) quantities in the registers of the computer system, or the registers and memories of the electronic device into other data similarly represented as physical quantities in the electronic memory, or registers, or other such information storage, transmission or display devices.

[0152] In some embodiments, the present disclosure also relates to an apparatus for performing the operations herein. The apparatus may be specially constructed for the required purpose, or it may include a general-purpose computer that is selectively activated or reconfigured by a computer program stored in the computer.

[0153] Embodiments of the present disclosure may be embodied in many different forms, including but not limited to computer program logic used with a processor (e.g., a microprocessor, a microcontroller, a digital signal processor, or a general purpose computer), programmable logic used with a programmable logic device (e.g., a field programmable gate array (FPGA), or other programmable logic device), discrete components, integrated circuits (e.g., an application specific integrated circuit (ASIC)), or any other device including any combination thereof. In a typical embodiment of the present disclosure, some or all of the processing of data collected using an OCT probe and a processor-based system is implemented as a collection of computer program instructions that are converted into a computer executable form, stored in, for example, a computer readable medium, and executed by a microprocessor under the control of an operating system. Thus, query responses and input data are transformed into processor-understandable instructions that are suitable for generating imaging data, detecting lumen boundaries, detecting stent struts, comparing measured vertical distances relative to set thresholds, and otherwise performing image comparisons, signal processing, lumen detection, stent detection, and comparing detected stents and other features and embodiments described above.

[0154] The computer program logic that implements all or part of the functionality previously described herein may be embodied in various forms, including but not limited to source code form, computer executable form, and various intermediate forms (e.g., forms generated by an assembler, compiler, linker, or locator). The source code may include a series of computer program instructions implemented in any of various programming languages ​​(e.g., object code, assembly language, or high-level language (e.g., Fortran, C, C++, JAVA, or HTML)) for use with various operating systems or operating environments. The source code may define and use various data structures and communication messages. The source code may be in a computer executable form (e.g., via an interpreter), or the source code may be converted (e.g., via a translator, assembler, or compiler) into a computer executable form.

[0155] The computer program may be permanently or temporarily fixed in any form (e.g., source code form, computer executable form, or intermediate form) in a tangible storage medium, such as a semiconductor memory device (e.g., RAM, ROM, PROM, EEPROM, or flash programmable RAM), a magnetic memory device (e.g., a magnetic disk or fixed disk), an optical memory device (e.g., a CD-ROM), a PC card (e.g., a PCMCIA card), or other memory device. The computer program may be fixed in any form in a signal that can be transmitted to a computer using any of a variety of communication technologies (including but not limited to: analog technology, digital technology, optical technology, wireless technology (e.g., Bluetooth), network technology, and Internet technology). The computer program may be distributed in any form as a removable storage medium with the following accompaniment: printed or electronic documents (e.g., compressed package software), pre-loaded with a computer system (e.g., on a system ROM or fixed disk), or distributed from a server or electronic bulletin board through a communication system (e.g., the Internet or the World Wide Web).

[0156] Hardware logic (including programmable logic used with a programmable logic device) that implements all or part of the functionality previously described herein may be designed using conventional manual methods, or may be designed, acquired, simulated, or electronically documented using various tools such as computer-aided design (CAD), hardware description languages ​​(e.g., VHDL or AHDL), or PLD programming languages ​​(e.g., PALASM, ABEL, or CUPL).

[0157] The programmable logic may be permanently or temporarily fixed in a tangible storage medium, such as a semiconductor memory device (e.g., RAM, ROM, PROM, EEPROM, or flash programmable RAM), a magnetic storage device (e.g., a magnetic disk or fixed disk), an optical storage device (e.g., a CD-ROM), or other storage device. The programmable logic may be fixed in a signal that may be transmitted to a computer using any of a variety of communication technologies, including but not limited to analog, digital, optical, wireless (e.g., Bluetooth), network, and networking technologies. The programmable logic may be distributed as a removable storage medium with accompanying printed or electronic documents (e.g., compressed package software), preloaded with a computer system (e.g., on a system ROM or fixed disk), or distributed from a server or electronic bulletin board via a communication system (e.g., the Internet or the World Wide Web).

[0158] Various examples of suitable processing modules are discussed in more detail below. As used herein, module refers to software, hardware or firmware suitable for performing specific data processing or data transmission tasks. Generally, in a preferred embodiment, module refers to a software routine, program or other memory resident application suitable for receiving, transforming, routing and processing instructions, or various types of data (e.g., OCT scan data, IVUS scan data, interferometer signal data, target stent contour, stent post-expansion lumen contour and image, indicating a fully expanded stent through interpolation of the lumen contour view, based on the ratio of the lumen contour of the expanded stent to the geometric value of the fully expanded lumen contour, stent expansion level mark (color, shadow, etc.), highlight / emphasize pixel attributes, side branch position, side branch diameter, stent expansion percentage or score, stent preoperative FFR value, stent postoperative FFR value, and other preoperative stent values ​​and postoperative stent values, and other information of interest).

[0159] The computers and computer systems described herein may include operably associated computer-readable media, such as memory for storing software applications (which are used to obtain, process, store and / or communicate data). It will be understood that such memory may be internal, external, remote or local with respect to the computer or computer system to which it is operably associated.

[0160] The memory may also include any device for storing software or other instructions, including (for example, but not limited to): a hard disk, an optical disk, a floppy disk, a DVD (digital versatile disk), a CD (compact disk), a memory stick, a flash memory, a ROM (read-only memory), a RAM (random access memory), a DRAM (dynamic random access memory), a PROM (programmable ROM), an EEPROM (extended erasable PROM) and / or other similar computer-readable media.

[0161] Typically, the computer-readable storage medium used in association with the embodiments of the disclosure described herein may include any storage medium capable of storing instructions executed by a programmable device. Where applicable, the method steps described herein may be embodied or executed as instructions stored on a computer-readable storage medium or storage medium. These instructions may be software implemented in various programming languages ​​(e.g., C++, C, Java and / or various other software programming languages ​​that may be applied to create instructions according to embodiments of the disclosure).

[0162] The storage medium may be non-transitory or include a non-transitory device. Thus, a non-transitory storage medium or a non-transitory device may include a tangible device, meaning that the device has a specific physical form, although the device may change its physical state. Thus, for example, non-transitory means that despite this change in state, the device remains tangible.

[0163] The aspects, embodiments, features and examples of the present disclosure are considered to be illustrative in all respects and are not intended to limit the present disclosure, the scope of which is limited only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the disclosure claimed.

[0164] The use of headings and sections in this application is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.

[0165] Throughout the application, where compositions are described as having, containing, or comprising specific components, or where methods are described as having, containing, or comprising specific process steps, it is contemplated that the compositions of the present teachings also consist essentially of, or consist of, the recited components, and that the methods of the present teachings also consist essentially of, or consist of, the recited method steps.

[0166] In the present application, where an element or assembly is referred to as being included in a list of the element or assembly and / or selected from a list of the element or assembly, it should be understood that the element or assembly can be any one of the elements or assemblies described, and can be selected from a group consisting of two or more of the elements or assemblies described. In addition, it should be understood that the elements and / or features of the compositions, devices, or methods described herein can be combined in various ways without departing from the spirit and scope of the present teachings (whether explicit or implicit).

[0167] Use of the terms "includes," "comprising," "containing," "having," "having," or "having" should generally be construed as open ended and non-limiting unless specifically stated otherwise.

[0168] The use of the singular herein includes the plural (and vice versa) unless specifically stated otherwise. In addition, the singular forms "a", "an", and "the" include the plural forms unless the context clearly dictates otherwise. In addition, to the extent that the term "approximately" or "substantially" is used before a quantitative value, the present teachings also include the specific quantitative value itself unless specifically stated otherwise. As used herein, the terms "approximately" and "substantially" refer to variations that can occur in a quantity, for example, through real-world processes of measuring or processing; through unintentional errors in these processes; through differences / failures in the manufacture of materials (e.g., composite tapes); through defects; and equivalent variations recognized by those skilled in the art, as long as such variations do not encompass known values ​​of prior art practice. In general, the terms "approximately" and "substantially" refer to a value or range of values ​​that is greater than or less than 1 / 10 of the stated value, for example, ±10%.

[0169] It should be understood that the order of steps or the order for performing certain actions is unimportant as long as this teaching remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0170] The use of headings and sections in this application is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure. It is intended that only those claims that use the words "means for..." be interpreted under 35 USC 112, Section 6. In the absence of "means for..." in a claim, such claim should not be interpreted under 35 USC 112. Limitations in the specification are not intended to be interpreted as any claim unless such limitations are explicitly included in a claim.

[0171] When a value or range of values ​​is given, each value and the endpoints of the given range and the values ​​therebetween can be increased or decreased by 20% while still remaining within the teachings of the present disclosure, unless some different range is specifically mentioned.

[0172] In the case of providing a range or list of values, each intermediate value between the upper and lower limits of the list of the range or values ​​is considered individually and is included in the present disclosure, as if each value is specifically listed in this article. In addition, between the upper and lower limits of a given range and including the smaller range of the upper and lower limits is expected and is included in the present disclosure. The list of exemplary values ​​or ranges is not to abandon other values ​​or ranges between the upper and lower limits of a given range (and including the upper and lower limits of a given range).

[0173] It should be understood that the drawings and description of the present disclosure have been simplified to illustrate the elements related to the present disclosure for a clear understanding, while other elements have been removed for the purpose of clarity. However, it will be appreciated by those of ordinary skill in the art that these elements and other elements may be desirable. However, because such elements are well known in the art, and because they do not promote a better understanding of the present disclosure, discussion of these elements is not provided herein. It should be understood that the drawings are presented for illustrative purposes rather than as construction drawings. The details and modifications or alternative embodiments omitted are within the horizon of those of ordinary skill in the art.

[0174] It is understood that in some aspects of the present disclosure, a single component may be replaced by multiple components, and multiple components may be replaced by a single component to provide an element or structure, or to perform a given function or functions. Unless such replacement will not operate to practice certain embodiments of the present disclosure, such replacement is considered to be within the scope of the present disclosure.

[0175] The examples presented herein are intended to illustrate potential and specific implementation of the present invention. It will be appreciated that these examples are primarily intended to illustrate the purpose of the disclosure to those skilled in the art. Without departing from the spirit of the present disclosure, there may be variations of these figures or operations described herein. For example, in some cases, method steps or operations may be performed or may be added, deleted or modified in different orders.

Claims

1. A method of evaluating stent expansion in a blood vessel defining a lumen, comprising: Scanning a blood vessel with a stent using a first imaging system to obtain a first set of blood vessel image data; storing the first set of vascular image data in an electronic memory device in electronic communication with the first imaging system; detecting stent struts along a length of the stented blood vessel using one or more software modules; generating a first representation of a segment of the blood vessel indicative of a level of stent expansion; determining a first end of the stent and a second end of the stent using the detected stent struts; defining a first offset distance (D1) from the first end of the bracket and a second offset distance (D2) from the second end of the bracket; generating a second representation of the segment of the blood vessel using D1 and D2 in combination with a tapered profile of the segment; as well as A target level of stent expansion along a vessel segment is determined by comparing a first value associated with the first representation and a second value associated with the second representation at different locations along the length of the segment.

Images