# US 8,543,187 B2 · Non-contrast MRI signal acquisition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,187 B2 - Document ID: US8543187B2 - Status: Granted - Kind: B2 - Application number: 12/923,892 - Filed: 2010-10-13 - Published: 2012-04-19 - Granted: 2013-09-24 - Earliest claimed: 2010-10-13 - Assignees: Kabushiki Kaisha Toshiba; Toshiba Medical Systems Corporation - Applicants: Mitsue Miyazaki - Inventors: Mitsue Miyazaki - Web page: https://patentgrep.com/patent/US8543187B2 ## CPC - G01R 33/4838: {using spatially selective suppression or saturation of MR signals} - A61B 5/0037: {Performing a preliminary scan, e.g. a prescan for identifying a region of interest} - A61B 5/055: involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging - G01R 33/5635: {Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA]} - A61B 2576/00: Medical imaging apparatus involving image processing or analysis (A61B1/00009, A61B6/52 and A61B8/52 take precedence) - G16H 30/40: for processing medical images, e.g. editing - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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 A first plurality of MR signals from a patient's tissue at respectively corresponding successive first time increments extending over a first time interval including a substantial majority of a subject's cardiac cycle is acquired and analyzed to define a second time interval, shorter than the first time interval, during the cardiac cycle whereat there is a relatively steep rise in signal magnitudes as a function of time (e.g., corresponding with systole and diastole events of the cardiac cycle). A second plurality of MR signals is then acquired from tissue of the patient at respectively corresponding successive second time increments during the second time interval, the second time increments being substantially shorter than said first time increments. Image data representing at least one contrast-free image of flowing fluid vessels is generated based on the second plurality of MR signals. ## Claims ### Claim 1 A computer-implemented method for acquiring a plurality of MR-images at respectively corresponding times related to a subject's cardiac cycle, said method comprising use of an MRI system having at least one programmed computer to: acquire a first plurality of MR signals from a patient's tissue at respectively corresponding successive first time increments extending over a first time interval including a substantial majority of a subject's cardiac cycle; analyze data representing magnitudes of the acquired first plurality of MR signals to define a second time interval, shorter than said first time interval, during the cardiac cycle whereat there is a relatively steep rise in signal magnitudes as a function of time corresponding with systole and diastole events of the cardiac cycle; acquire a second plurality of MR signals from tissue of said patient at respectively corresponding successive second time increments during said second time interval, said second time increments being substantially shorter than said first time increments; generate image data representing at least one contrast-free image of flowing fluid vessels based on said second plurality of MR signals respectively acquired at different times during said second time interval; and output said generated image data to at least one of: (a) a display, (b) a non-transitory data storage medium, and (c) a remote device. ### Claim 2 (depends on 1) A computer-implemented method as in claim 1, wherein said data representing magnitudes of the acquired first plurality of MR signals is displayed to an operator and an operator control input is accepted to define said second time interval based on such displayed data. ### Claim 3 (depends on 2) A computer-implemented method as in claim 2, wherein said second time increment is automatically determined by the programmed computer based on said operator-defined time interval. ### Claim 4 (depends on 1) A computer-implemented method as in claim 1, wherein said data representing magnitudes of the acquired first plurality of MR signals is automatically analyzed by said programmed computer and said second time interval is automatically defined by said programmed computer based on such data. ### Claim 5 (depends on 1) A computer-implemented method as in claim 1, wherein said first time increments are on the order of 100 ms and said second time increments are on the order of 10 ms. ### Claim 6 (depends on 1) A computer-implemented method as in claim 1, wherein said first time interval is triggered to begin by the occurrence of an R-peak in a QRS cardiac cycle. ### Claim 7 (depends on 1) A computer-implemented method as in claim 1, wherein an image subtraction process is implemented to produce an image of flowing fluid vessels and the second time interval defines a time interval between systole and diastole of a cardiac cycle. ### Claim 8 (depends on 7) A computer-implemented method as in claim 7, wherein successive difference images are generated between an MR-image acquired at systole and successive MR-images acquired at times approaching and/or at diastole. ### Claim 9 (depends on 8) A computer-implemented method as in claim 8, wherein said successive difference images are displayed in cine mode to display flow-like hemodynamic images. ### Claim 10 (depends on 7) A computer-implemented method as in claim 7, wherein said image of flowing fluid vessels is a 2D image. ### Claim 11 (depends on 7) A computer-implemented method as in claim 7, wherein said image of flowing fluid vessels is a 3D image. ### Claim 12 (depends on 1) A computer-implemented method as in claim 1, wherein a time-SLIP (spatial labeling inversion pulse) process is implemented to produce a contrast-free MR-image of flowing fluid vessels. ### Claim 13 (depends on 1) A computer-implemented method as in claim 1, wherein a 2D BBTI (black-blood time to inversion) preparation scan is implemented to produce a contrast-free MR-image of flowing fluid vessels. ### Claim 14 Apparatus for acquiring a plurality of MR-images at respectively corresponding times related to a subject's cardiac cycle, said apparatus comprising an MRI system having at least one programmed computer configured to include: means for acquiring a first plurality of MR signals from a patient's tissue at respectively corresponding successive first time increments extending over a first time interval including a substantial majority of a subject's cardiac cycle; means for analyzing data representing magnitudes of the acquired first plurality of MR signals to define a second time interval, shorter than said first time interval, during the cardiac cycle whereat there is a relatively steep rise in signal magnitudes as a function of time corresponding with systole and diastole events of the cardiac cycle; means for acquiring a second plurality of MR signals from tissue of said patient at respectively corresponding successive second time increments during said second time interval, said second time increments being substantially shorter than said first time increments; means for generating image data representing at least one contrast-free image of flowing fluid vessels based on said second plurality of MR signals respectively acquired at different times during said second time interval; and means for outputting said generated image data to at least one of: (a) a display, (b) a non-transitory data storage medium, and (c) a remote device. ### Claim 15 (depends on 14) Apparatus as in claim 14, wherein said data representing magnitudes of the acquired first plurality of MR signals is displayed to an operator and an operator control input is accepted to define said second time interval based on such displayed data. ### Claim 16 (depends on 15) Apparatus as in claim 15, wherein said second time increment is automatically determined by the programmed computer based on said operator-defined time interval. ### Claim 17 (depends on 14) Apparatus as in claim 14, wherein said data representing magnitudes of the acquired first plurality of MR signals is automatically analyzed by said programmed computer and said second time interval is automatically defined by said programmed computer based on such data. ### Claim 18 (depends on 14) Apparatus as in claim 14, wherein said first time increments are on the order of 100 ms and said second time increments are on the order of 10 ms. ### Claim 19 (depends on 14) Apparatus as in claim 14, wherein said first time interval is triggered to begin by the occurrence of an R-peak in a QRS cardiac cycle. ### Claim 20 (depends on 14) Apparatus as in claim 14, wherein an image subtraction process is implemented to produce an image of flowing fluid vessels and the second time interval defines a time interval between systole and diastole of a cardiac cycle. ### Claim 21 (depends on 20) Apparatus as in claim 20, wherein successive difference images are generated between an MR-image acquired at systole and successive MR-images acquired at times approaching and/or at diastole. ### Claim 22 (depends on 21) Apparatus as in claim 21, wherein said successive difference images are displayed in cine mode to display flow-like hemodynamic images. ### Claim 23 (depends on 20) Apparatus as in claim 20, wherein said image of flowing fluid vessels is a 2D image. ### Claim 24 (depends on 20) Apparatus as in claim 20, wherein said image of flowing fluid vessels is a 3D image. ### Claim 25 (depends on 14) Apparatus as in claim 14, wherein a time-SLIP (spatial labeling inversion pulse) process is implemented to produce a contrast-free MR-image of flowing fluid vessels. ### Claim 26 (depends on 14) Apparatus as in claim 14, wherein a 2D BBTI (black-blood time to inversion) preparation scan is implemented to produce a contrast-free MR-image of flowing fluid vessels.