Methods and systems for determining hemodynamic information for one or more arterial segments

Abstract

The systems and methods can accurately and efficiently determine boundary conditions for an arterial segment and thereby efficiently determine hemodynamic information for that segment. The method may include receiving medical image data of a patient. The method may further include generating a geometrical representation of the one or more arterial segments from the medical image data. The method may further include determining boundaries and geometry data for each arterial segment. The method may further include determining boundary conditions for the inflow boundary and each outflow boundary. The boundary conditions for each outflow boundary may be determined using an outflow distribution parameter. The outflow distribution parameter may be determined using the geometry data for one or more of the one or more outflow boundaries, stored hemodynamic data, or a combination thereof. The method may further include determining flow field for each arterial segment and determining hemodynamic information.

What is claimed: 
     
         1 . A computer-implemented method of determining hemodynamic information for a patient, the method comprising:
 receiving medical image data of the patient, the medical image data including representations of tissue and blood of one or more arterial segments and surrounding area;   generating a geometrical representation of the one or more arterial segments from the medical image data, wherein a resulting geometrical representation is a three-dimensional model of a spatial volume of lumens of one or more arterial segments;   determining boundaries and geometry data for each arterial lumen segment, the boundaries of which include a luminal volume, an inflow boundary, one or more outflow boundaries, and additional outflow boundaries that each represent a branch or bifurcation in the one or more arterial segments and are disposed between the inflow boundary and a first outflow boundary of the one or more outflow boundaries, wherein the inflow boundary and the one or more outflow boundaries corresponding to a luminal cross-section of the each arterial segment, and the geometry data including a radius for the inflow boundary and a radius for each outflow boundary;   determining boundary conditions for the geometrical representation using the three-dimensional model, the boundary conditions including an interface between a luminal volume and arterial walls, an inflow boundary condition for the inflow boundary, an outflow boundary condition determined using stored hemodynamic data and the radius for each outflow boundary, and a final outflow rate distribution among the outflow boundaries of the segments that is determined using a minimization of outflow energy approach encompassing all outflow boundaries;   determining a patient-specific flow field for each arterial segment incorporating all of the boundary conditions;   determining hemodynamic information using the boundary conditions, the flow field, and patient-specific pressure; and   providing an interactive display output of the hemodynamic information that enables receipt of user inputs to manipulate arterial segments and assess diagnostic information associated with the hemodynamic information.   
     
     
         2 . The method according to  claim 1 , wherein:
 an outflow distribution parameter is determined using a ratio of a radius for the first outflow boundary and a radius for a second outflow boundary, and the stored hemodynamic data; and   the stored hemodynamic data defines a relationship between (i) the ratio of the radius of the first outflow boundary and the radius of the second outflow boundary and (ii) a ratio of an outflow boundary condition for the first outflow boundary and an outflow boundary condition for the second outflow boundary.   
     
     
         3 . The method according to  claim 2 , wherein:
 the outflow distribution parameter is used to determine an outflow boundary condition for the first outflow boundary, the second outflow boundary, and each additional outflow boundary.   
     
     
         4 . The method according to  claim 1 , wherein:
 the geometrical representation of the one or more arterial segments is discretized into a three-dimensional volumetric mesh; and   the geometrical representation includes a surface mesh representing a boundary of a vessel wall of each segment.   
     
     
         5 . The method according to  claim 1 , wherein the flow field is determined using only the geometrical representation, the geometrical data and the boundary conditions. 
     
     
         6 . The method according to  claim 1 , wherein the medical image data is computed tomography image data of the patient. 
     
     
         7 . The method according to  claim 1 , wherein the hemodynamic information includes fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), wall shear stress (WSS), axial plaque stress (APS), hyperemic and resting diastolic pressure (Pd)/aortic pressure (Pa) indexes, pressure indices over a range of physiologic states, or a combination thereof. 
     
     
         8 . The method according to  claim 1  further comprising:
 receiving information regarding a position of a virtual stent disposed along one or more of the segments of the geometrical representation; and 
 updating the display output of the hemodynamic information. 
 
     
     
         9 . The method according to  claim 1 , wherein:
 the one or more arterial segments correspond to one or more coronary arterial segments.   
     
     
         10 . A system for determining hemodynamic information for a patient, the system comprising:
 at least one processor; and   a memory that stores computer-executable instructions,   wherein the processor executes the computer-executable instructions to:   obtain medical image data of the patient, the medical image data including representations of tissue and blood of one or more arterial segments and surrounding area;   generate a geometrical representation of the one or more arterial segments from the medical image data, wherein a resulting geometrical representation is a three-dimensional model of a spatial volume of the one or more arterial segments;   determine boundaries and geometry data for each arterial lumen segment, the boundaries of which include a luminal volume, an inflow boundary, one or more outflow boundaries, and additional outflow boundaries that each represent a branch or bifurcation in the one or more arterial segments and are disposed between the inflow boundary and a first outflow boundary of the one or more outflow boundaries, wherein the inflow boundary and the one or more outflow boundaries corresponding to a luminal cross-section of each arterial segment; the geometry data including a radius for the inflow boundary and for each outflow boundary;   determine boundary conditions for the geometrical representation using the three-dimensional model, the boundary conditions including an interface between a luminal volume and arterial walls, an inflow boundary condition for the inflow boundary, an outflow boundary condition determined using stored hemodynamic data and the radius for each outflow boundary, and a final outflow rate distribution among the outflow boundaries of the segments that is determined using a minimization of outflow energy approach encompassing all outflow boundaries;   determine a patient-specific flow field for each arterial segment incorporating all of the boundary conditions;   determine hemodynamic information using the boundary conditions, the flow field, and patient-specific pressure; and   provide an interactive display output of the hemodynamic information that enables receipt of user inputs to manipulate arterial segments and assess diagnostic information associated with the hemodynamic information.   
     
     
         11 . The system according to  claim 10 , wherein:
 an outflow distribution parameter is determined using a ratio of a radius for the first outflow boundary and a radius for a second outflow boundary and the stored hemodynamic data; and   the stored hemodynamic data defines a relationship between (i) the ratio of the radius of the first outflow boundary and the radius of the second outflow boundary and (ii) a ratio of the outflow boundary condition for the first outflow boundary and the outflow boundary condition for second outflow boundary.   
     
     
         12 . The system according to  claim 11 , wherein:
 the outflow distribution parameter is used to determine an outflow boundary condition for the first outflow boundary, the second outflow boundary, and each additional outflow boundary.   
     
     
         13 . The system according to  claim 10 , wherein:
 the geometrical representation of the one or more arterial segments is discretized into a three-dimensional volumetric mesh; and   the geometrical representation includes a surface mesh representing a boundary of a vessel wall of each segment.   
     
     
         14 . The system according to  claim 10 , wherein the flow field is determined using only the geometrical representation, the geometrical data and the boundary conditions. 
     
     
         15 . The system according to  claim 10 , wherein the medical image data is computed tomography image data of the patient. 
     
     
         16 . The system according to  claim 10 , wherein the hemodynamic information includes fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), wall shear stress (WSS), axial plaque stress (APS), hyperemic and resting diastolic pressure (Pd)/aortic pressure (Pa) indexes, pressure indices over a range of physiologic states, or a combination thereof. 
     
     
         17 . The system of according to  claim 10 , wherein information regarding a position of a virtual stent disposed along one or more of the segments of the geometrical representation is received, and wherein the display output of the hemodynamic information is updated in accordance with the information. 
     
     
         18 . The system according to  claim 10 , wherein:
 the one or more arterial segments corresponds to one or more coronary arterial segments.   
     
     
         19 . A non-transitory computer-readable medium storing instructions that, when executed by a processor, causes an information processing apparatus connected to:
 receive medical image data of a patient, the medical image data including representations of tissue and blood of one or more arterial segments and surrounding area;   generate a geometrical representation of the one or more arterial segments from the medical image data, wherein a resulting geometrical representation is a three-dimensional model of a spatial volume of lumens of one or more arterial segments;   determine boundaries and geometry data for each arterial lumen segment, the boundaries of which include a luminal volume, an inflow boundary, one or more outflow boundaries, and additional outflow boundaries that each represent a branch or bifurcation in the one or more arterial segments and are disposed between the inflow boundary and a first outflow boundary of the one or more outflow boundaries, wherein the inflow boundary and the one or more outflow boundaries corresponding to a luminal cross-section of the each arterial segment, and the geometry data including a radius for the inflow boundary and a radius for each outflow boundary;   determine boundary conditions for the geometrical representation using the three-dimensional model, the boundary conditions including an interface between a luminal volume and arterial walls, an inflow boundary condition for the inflow boundary, an outflow boundary condition determined using stored hemodynamic data and the radius for each outflow boundary, and a final outflow rate distribution among the outflow boundaries of the segments that is determined using a minimization of outflow energy approach encompassing all outflow boundaries;   determine a patient-specific flow field for each arterial segment incorporating all of the boundary conditions;   determine hemodynamic information using the boundary conditions, the flow field, and patient-specific pressure; and   provide an interactive display output of the hemodynamic information that enables receipt of user inputs to manipulate arterial segments and assess diagnostic information associated with the hemodynamic information.   
     
     
         20 . The non-transitory computer-readable medium of  claim 19 , further storing instructions that, when executed by a processor, causes an information processing apparatus connected to:
 determine an outflow distribution parameter using a ratio of a radius for the first outflow boundary and a radius for a second outflow boundary and the stored hemodynamic data, wherein the outflow distribution parameter is used to determine an outflow boundary condition for the first outflow boundary, the second outflow boundary, and each additional outflow boundary; and   define the stored hemodynamic data as relationship between (i) the ratio of the radius of the first outflow boundary and the radius of the second outflow boundary and (ii) a ratio of the outflow boundary condition for the first outflow boundary and the outflow boundary condition for second outflow boundary.