# US 11,298,096 B2 · Imaging method, controller and imaging system, for monitoring a patient post EVAR > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,096 B2 - Document ID: US11298096B2 - Status: Granted - Kind: B2 - Application number: 16/630,894 - Filed: 2018-07-12 - Published: 2020-05-21 - Granted: 2022-04-12 - Earliest claimed: 2017-07-17 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N. V. - Inventors: Laurence Rouet; Antoine Collet-Billon; Cecile Dufour; Robert Randall Entrekin - Web page: https://patentgrep.com/patent/US11298096B2 ## CPC - A61B 6/504: {for diagnosis of blood vessels, e.g. by angiography} - A61B 5/4842: {Monitoring progression or stage of a disease} - A61B 6/032: {Transmission computed tomography [CT]} - A61B 6/463: {characterised by displaying multiple images or images and diagnostic data on one display} - 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 8/54: {Control of the diagnostic device} - G16H 30/40: for processing medical images, e.g. editing - G16H 50/50: for simulation or modelling of medical disorders - 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 The invention provides a method of patient monitoring following endovascular aneurysm repair (EVAR) with a stent graft. It particularly applies to abdominal aortic aneurysm repair. A first 3D volume scan of the stent in situ is provided and a second, subsequent 3D volume scan of the stent is also provided. One or more fiducial markers are generated in a first image derived from the first scan and in a second image derived from the second scan. The fiducial markers identify recognizable features of the stent, such as the bifurcation point in the stent graft. A rigid 3D transform mapping based on the one or more fiducial markers is extracted and then a registration is applied to the first and second scans based on the 3D rigid transform between the first and second images. A size value is derived at the same location in the aneurysm from the first and second scans. The same location is determined with reference to the registered first and second images of the stent. A comparison of the size value from the first and second scans is used to assess a change in size of the aneurysm between the first and second scans. This change in size allows the clinician to evaluate disease progression. ## Claims ### Claim 1 A method of patient monitoring following endovascular aneurysm repair with a bifurcated stent graft having a stent body and two stent legs defining a bifurcation point at a junction of the two stent legs, the method comprising: receiving a previously generated first 3D volume scan of the bifurcated stent graft in situ; providing a second 3D volume scan of the bifurcated stent graft in situ; generating one or more fiducial markers in a first image derived from the first scan and in a second image derived from the second scan, wherein one of the fiducial markers is the bifurcation point; extracting a rigid 3D transform mapping based on the one or more fiducial markers; applying a registration to the first and second scans based on the 3D rigid transform between the first and second images; deriving a size value at the same location in the aneurysm from the first and second scans, where the same location is determined with reference to the registered first and second images of the bifurcated stent graft; and comparing the size value from the first and second scans to assess a change in size of the aneurysm between the first and second scans. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the aneurysm is an abdominal aortic aneurysm. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the first scan is a 3D-computed tomography scan. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the second scan is a 3D-ultrasound scan. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein the first scan is a baseline scan obtained within one month post-endovascular aneurysm repair. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein a time between the first and second scans is from one month to a lifetime of the patient. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein the first and second scans are consecutive scans. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein the registration applied to the first and second scans is a user-guided registration. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the method includes a further step after the registration of applying an imaged-based refinement of the registration. ### Claim 10 (depends on 1) The method as claimed in claim 1, wherein the size value is a diameter, area or volume of the aneurysm. ### Claim 11 (depends on 1) The method as claimed in claim 1, further comprising step of using the change in size to make a clinical evaluation of disease progression. ### Claim 12 (depends on 1) A tangible, non-transitory computer readable medium, which stores instructions, wherein the instructions, when executed by a processor, cause the processor to perform the method of claim 1. ### Claim 13 A controller for imaging a stent following endovascular aneurysm repair with a bifurcated stent graft having a stent body and two stent legs defining a bifurcation point at a junction of the two stent legs, wherein the controller is adapted to: receive a previously generated first 3D volume scan of the bifurcated stent graft in situ; acquire a second 3D volume scan of the bifurcated stent graft in situ; generate one or more fiducial markers in a first image derived from the first scan and in a second image derived from the second scan, wherein one of the fiducial markers is the bifurcation point; extract a rigid 3D transform mapping based on the one or more fiducial markers; apply a registration to the first and second scans based on the 3D rigid transform between the first and second images; derive a size value at the same location in the aneurysm from the first and second scans, where the same location is determined with reference to the registered first and second images of the bifurcated stent graft; and compare the size value from the first and second scans to assess a change in size of the aneurysm between the first and second scans. ### Claim 14 (depends on 13) The controller of claim 13, wherein the aneurysm is an abdominal aortic aneurysm. ### Claim 15 (depends on 13) The controller as claimed in claim 13, wherein the first scan is a 3D-computed tomography scan. ### Claim 16 (depends on 13) The controller as claimed in claim 13, wherein the second scan is a 3D-ultrasound scan. ### Claim 17 (depends on 13) The controller as claimed in claim 13, wherein the first scan is a baseline scan obtained within one month post-endovascular aneurysm repair. ### Claim 18 An imaging system, comprising: a beamformer; a display device; a controller; and a tangible, non-transitory computer readable medium, which stores instructions, which when executed by the controller, cause the controller to: receive a previously generated first 3D volume scan of a stent in situ; acquire a second 3D volume scan of the stent in situ; generate one or more fiducial markers in a first image derived from the first scan and in a second image derived from the second scan, wherein one of the fiducial markers is a bifurcation point; extract a rigid 3D transform mapping based on the one or more fiducial markers; apply a registration to the first and second scans based on the 3D rigid transform between the first and second images; derive a size value at the same location in an aneurysm from the first and second scans, where the same location is determined with reference to the registered first and second images of the stent; and compare the size value from the first and second scans to assess a change in size of the aneurysm between the first and second scans. ### Claim 19 (depends on 18) The controller of claim 18, wherein the aneurysm is an abdominal aortic aneurysm. ### Claim 20 (depends on 18) The imaging system as claimed in claim 18, wherein the first scan is a 3D-computed tomography scan. ### Claim 21 (depends on 18) The imaging system as claimed in claim 18, wherein the second scan is a 3D-ultrasound scan. ### Claim 22 (depends on 18) The imaging system as claimed in claim 18, wherein the first scan is a baseline scan obtained within one month post-endovascular aneurysm repair.