# US 2023/0054891 A1 · Systems And Methods Of Identifying Vessel Attributes Using Extravascular Images > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054891 A1 - Document ID: US20230054891A1 - Status: Published application - Kind: A1 - Application number: 17/890,672 - Filed: 2022-08-18 - Published: 2023-02-23 - Earliest claimed: 2021-08-19 - Assignees: LightLab Imaging, Inc. - Applicants: LightLab Imaging, Inc. - Inventors: Wei Chiu; Shimin Li; Ajay Gopinath; Jacob Segev; Lorina Dascal - Web page: https://patentgrep.com/patent/US20230054891A1 ## CPC - A61B 5/0066: {Optical coherence imaging} - A61B 5/02007: {Evaluating blood vessel condition, e.g. elasticity, compliance} - A61B 5/066: {Superposing sensor position on an image of the patient, e.g. obtained by ultrasound or x-ray imaging} - A61B 5/7425: {Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image} - A61B 6/504: {for diagnosis of blood vessels, e.g. by angiography} - A61B 6/5217: {extracting a diagnostic or physiological parameter from medical diagnostic data} - A61B 6/5247: {combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound} - A61B 8/0891: {for diagnosis of blood vessels} - A61B 8/12: in body cavities or body tracts, e.g. by using catheters - A61B 8/5223: {for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012)} - A61B 8/5261: {combining images from different diagnostic modalities, e.g. ultrasound and X-ray} - G16H 30/20: for handling medical images, e.g. DICOM, HL7 or PACS - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA ## Abstract Systems and methods are disclosed for identifying features of a blood vessel using extravascular and intravascular images in order to estimate a virtual flow reserve (VFR) of the imaged blood vessel. Aspects of the disclosure include using extravascular images to estimate the size of the blood vessel in regions that have not been intravascularly imaged. The VFR estimation may be based on a resistance model that incorporates both the intravascular image data and the estimated blood vessel size. In other aspects, multiangled extravascular images are captured and analyzed in order to identify the size and orientation of branch vessels. ## Claims ### Claim 1 A method for identifying attributes of a blood vessel, the method comprising: receiving, by one or more processors, a plurality of extravascular images of a vessel during a pullback of an intravascular imaging probe having a defined pullback length along a first region of the vessel; detecting, by the one or more processors, locations of one or more markers in the plurality of extravascular images; correlating, by the one or more processors, the first region of the vessel represented in the plurality of extravascular images with the pullback length based on the location of the one or more markers in the plurality of extravascular images; and determining, by the one or more processors, a size of a second region of the vessel represented in the plurality of extravascular images based the correlation of the first region of the vessel represented in the plurality of extravascular images with the pullback length. ### Claim 2 (depends on 1) The method of claim 1, wherein the size of the second region of the vessel includes at least one of a length of the second region, a cross-section diameter within the second region, and a cross-sectional area within the second region. ### Claim 3 (depends on 1) The method of claim 1, further comprising computing, by the one or more processors, a virtual flow reserve (VFR) of the vessel based on a plurality of images captured by the intravascular imaging probe and based on the determined size of the second region of the vessel. ### Claim 4 (depends on 3) The method of claim 3, wherein the VFR of the vessel is computed based on a distance between a vessel centerline and a boundary of the vessel the second region of the vessel identified in at least one of the plurality of extravascular images. ### Claim 5 (depends on 1) The method of claim 1, wherein the second region of the vessel includes at least one of a distal epicardial region and a proximal epicardial region of the vessel. ### Claim 6 (depends on 5) The method of claim 5, wherein determining a size of a second region of the vessel includes determining a length of the distal epicardial region and a length of the proximal epicardial region. ### Claim 7 (depends on 1) The method of claim 1, wherein correlating the first region of the vessel represented in the plurality of extravascular images with the pullback length includes scaling a lumen size represented in at least one of the plurality of the extravascular images. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of extravascular images are taken from a plurality of locations relative to the vessel. ### Claim 9 (depends on 8) The method of claim 8, further comprising analyzing, by the one or more processors, the plurality of extravascular images so as to identify a three-dimensional orientation of one or more objects relative to the vessel. ### Claim 10 (depends on 9) The method of claim 9, wherein the one or more objects comprises a branch from the vessel and wherein the three-dimensional orientation of the branch includes a position and takeoff angle of the branch relative to the vessel. ### Claim 11 (depends on 10) The method of claim 10, further comprising computing, by the one or more processors, a virtual flow reserve (VFR) of the vessel based on the identified position and takeoff angle of the branch. ### Claim 12 A system for identifying attributes of a blood vessel, the system comprising: one or more memories for storing images of a vessel; and and one or more processors configured to: capture a plurality of extravascular images of a vessel during a pullback of an intravascular imaging probe having a defined pullback length along a first region of the vessel; detect locations of one or more markers in the plurality of extravascular images; correlate the first region of the vessel represented in the plurality of extravascular images with the pullback length based on the location of the one or more markers in the plurality of extravascular images; and determine a size of a second region of the vessel represented in the plurality of extravascular images based the correlation of the first region of the vessel represented in the plurality of extravascular images with the pullback length. ### Claim 13 (depends on 12) The system of claim 12, wherein the size of the second region of the vessel includes at least one of a length of the second region, a cross-section diameter within the second region, and a cross-sectional area within the second region. ### Claim 14 (depends on 12) The system of claim 12, wherein the one or more processors are further configured to compute a virtual flow reserve (VFR) of the vessel based on a plurality of images captured by the intravascular imaging probe and based on the determined size of the second region of the vessel. ### Claim 15 (depends on 14) The system of claim 14, wherein the VFR of the vessel is computed based on a distance between a vessel centerline and a boundary of the vessel the second region of the vessel identified in at least one of the plurality of extravascular images. ### Claim 16 (depends on 12) The system of claim 12, wherein the second region of the vessel includes at least one of a distal epicardial region and a proximal epicardial region of the vessel. ### Claim 17 (depends on 12) The system of claim 12, wherein correlating the first region of the vessel represented in the plurality of extravascular images with the pullback length includes scaling a lumen size represented in at least one of the plurality of the extravascular images. ### Claim 18 (depends on 12) The system of claim 12, wherein the one or more processors are further configured to analyze the plurality of extravascular images so as to identify a position and takeoff angle of a branch relative to the vessel. ### Claim 19 (depends on 18) The system of claim 18, wherein the one or more processors are further configured to compute a virtual flow reserve (VFR) of the vessel based on the identified position and takeoff angle of the branch. ### Claim 20 A method for identifying attributes of a vessel, the method comprising: receiving, by one or more processors, a plurality of extravascular images captured at a plurality of angulations relative to a patient; generating, by the one or more processors, a three-dimensional model of a vessel based on the plurality of extravascular images; identifying, by the one or more processors, locations within the vessel for which an intravascular pullback procedure will be conducted; estimating, by the one or more processors, a size of the vessel at one or more regions not included within the identified locations, wherein the estimation is based on the three-dimensional model; and computing a virtual flow reserve (VFR) of the vessel based on the estimated size of the vessel. ### Claim 21 (depends on 20) The method of claim 20, further comprising: identifying, by the one or more processors, one or more bifurcations along the vessel; and estimating, by the one or more processors, a size and orientation of a branch vessel at the one or more bifurcations; wherein computing the VFR of the vessel is based on the estimated size and orientation of the branch vessel. ### Claim 22 (depends on 21) The method of claim 21, wherein the orientation of the branch vessel comprises a takeoff angle of the branch vessel relative to the vessel.