Method and system for comprehensive patient-specific modeling of the heart
View Patent ↗A method and system for patient-specific modeling of the whole heart anatomy, dynamics, hemodynamics, and fluid structure interaction from 4D medical image data is disclosed. The anatomy and dynamics of the heart are determined by estimating patient-specific parameters of a physiological model of the heart from the 4D medical image data for a patient. The patient-specific anatomy and dynamics are used as input to a 3D Navier-Stokes solver that derives realistic hemodynamics, constrained by the local anatomy, along the entire heart cycle. Fluid structure interactions are determined iteratively over the heart cycle by simulating the blood flow at a given time step and calculating the deformation of the heart structure based on the simulated blood flow, such that the deformation of the heart structure is used in the simulation of the blood flow at the next time step. The comprehensive patient-specific model of the heart representing anatomy, dynamics, hemodynamics, and fluid structure interaction can be used for non-invasive assessment and diagnosis of the heart, as well as virtual therapy planning and cardiovascular disease management. Parameters of the comprehensive patient-specific model are changed or perturbed to simulate various conditions or treatment options, and then the patient specific model is recalculated to predict the effect of the conditions or treatment options.
1. A method for simulating blood flow in the heart based on 4D medical image data, comprising:
generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data; and
simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework, wherein the simulating blood flow in the heart comprises:
imposing no-slip boundary conditions to a fluid region of the anatomical model based on a location of a zero level of a level set function used to embed the patient-specific 4D anatomical model in a computational domain.
2. The method of claim 1 , wherein the patient-specific 4D anatomical model of the heart comprises a plurality of heart components, and the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
simulating blood flow separately in one or more of the plurality of heart components of the patient-specific 4D anatomical model.
3. The method of claim 1 , wherein the patient-specific 4D anatomical model of the heart comprises a plurality of heart components, and the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
simulating blood flow simultaneously in each of the plurality of heart components of the patient-specific 4D anatomical model.
4. The method of claim 1 , wherein the patient-specific 4D anatomical model of the heart comprises a plurality of heart components, and the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises, for each of the plurality of time steps:
calculating convective updates to a level set function and velocity based on the location of the patient-specific 4D anatomical model at the current time step;
calculating a semi-implicit update for the velocity representing a viscous force contribution at the current time step;
calculating a pressure update at the current time step by solving a Poisson equation with Neumann boundary conditions; and
calculating a new velocity update for the current time step based on the semi-implicit velocity update and the pressure update.
5. The method of claim 1 , wherein the patient-specific 4D anatomical model comprises a sequence of patient-specific 3D anatomical models of the heart over the heart cycle, and the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
interpolating the sequence of patient-specific 3D anatomical models to derive a location of the patient-specific 4D anatomical model at at least one of the plurality of time steps.
6. The method of claim 1 , wherein the step of generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data comprises:
generating a patient specific multi-scale anatomical model of at least one heart component, the multi-scale anatomical model including a coarse anatomical model of the at least one heart component and a fine anatomical model of the at least one heart component.
7. The method of claim 6 , wherein the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
simulating the blood flow in the at least one heart component by solving Navier-Stokes equations constrained by the fine anatomical model of the at least one heart component.
8. The method of claim 7 , wherein the at least one heart component comprises the left ventricle and the fine anatomical model of the left ventricle includes the papillary muscles and trabeculae.
9. A method for comprehensive patient-specific modeling of the heart based on 4D medical image data, comprising:
generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data;
simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework;
calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step; and
repeating the simulating and calculating steps for a plurality of time steps, wherein the current location of the at least one heart component at the current time step is determined at least in part based on the deformation of the at least one heart component calculated at a previous time step.
10. The method of claim 9 , further comprising:
comparing the calculated deformation of the at least one heart component with an observed deformation of the at least one heart component in the 4D medical imaging data to determine a biomechanical parameter of the at least one heart component.
11. The method of claim 9 , wherein the at least one heart component is the aorta.
12. The method of claim 9 , wherein the step of simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework comprises:
calculating pressure at a wall interface of the at least one heart component at the current time step due to the simulated blood flow in the at least one heart component.
13. The method of claim 12 , wherein the step of calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprises:
calculating a deformation of a wall of the at least one heart component due to the pressure at the wall interface of the at least one heart component.
14. The method of claim 9 , wherein the step of calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprises:
calculating the deformation of the at least one heart component based on an internal force that models passive properties of the tissue of the at least one heart component and an external force that models loading generated by the blood flow inside the at least one heart component.
15. A method of predictive planning using a comprehensive patient-specific 4D heart model, comprising:
generating a comprehensive patient-specific 4D model of the heart from 4D medical imaging data;
adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition; and
re-generating the comprehensive patient-specific 4D model of the heart to simulate the effect of the adjusted portion on the comprehensive patient-specific 4D model.
16. The method of claim 15 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
adjusting an anatomical parameter of the comprehensive patient-specific 4D model.
17. The method of claim 15 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
adjusting a hemodynamic parameter of the comprehensive patient-specific 4D model.
18. The method of claim 15 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
adjusting a biomechanical parameter of the comprehensive patient-specific 4D model.
19. The method of claim 15 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
adjusting at least one of an anatomical parameter, a hemodynamic parameter, and a biomechanical parameter of the comprehensive patient-specific 4D model to simulate progression of a disease in the heart.
20. The method of claim 15 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart.
21. The method of claim 20 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart comprises:
virtually simulating percutaneous artificial valve implantation in the comprehensive patient-specific 4D model.
22. The method of claim 20 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart comprises:
virtually simulating stent deployment at an aneurysm in a portion of the comprehensive patient-specific 4D model.
23. The method of claim 20 , wherein the step of adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart comprises:
virtually simulating resection of an aneurysm in a portion of the comprehensive patient-specific 4D model.
24. The method of claim 23 , wherein the step of re-generating the comprehensive patient-specific 4D model of the heart to simulate the effect of the adjusted portion on the comprehensive patient-specific 4D model comprises:
simulating blood flow and fluid structure interactions in the portion of the comprehensive patient-specific 4D model based on the simulated resection of the aneurysm.
25. An apparatus for simulating blood flow in the heart based on 4D medical image data, comprising:
means for generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data; and
means for simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework, wherein the means for simulating blood flow comprises:
means for imposing no-slip boundary conditions to a fluid region of the anatomical model based on a location of a zero level of a level set function used to embed the patient-specific 4D anatomical model in a computational domain.
26. The apparatus of claim 25 , wherein the patient-specific 4D anatomical model of the heart comprises a plurality of heart components, and the means for simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
means for calculating convective updates to a level set function and velocity based on the location of the patient-specific 4D anatomical model at a current time step;
means for calculating a semi-implicit update for the velocity representing a viscous force contribution at the current time step;
means for calculating a pressure update at the current time step by solving a Poisson equation with Neumann boundary conditions; and
means for calculating a new velocity update for the current time step based on the semi-implicit velocity update and the pressure update.
27. The apparatus of claim 25 , wherein the means for generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data comprises:
means for generating a patient specific multi-scale anatomical model of at least one heart component, the multi-scale anatomical model including a coarse anatomical model of the at least one heart component and a fine anatomical model of the at least one heart component.
28. The apparatus of claim 27 , wherein the means for simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprises:
means for simulating the blood flow in the at least one heart component by solving Navier-Stokes equations constrained by the fine anatomical model of the at least one heart component.
29. An apparatus for comprehensive patient-specific modeling of the heart based on 4D medical image data, comprising:
means for generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data;
means for simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework, wherein the current location of the at least one heart component at the current time step is determined at least in part based on a deformation of the at least one heart component calculated at a previous time step; and
means for calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step.
30. The apparatus of claim 29 , further comprising:
means for comparing the calculated deformation of the at least one heart component with an observed deformation of the at least one heart component in the 4D medical imaging data to determine a biomechanical parameter of the at least one heart component.
31. The apparatus of claim 29 , wherein the means for simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework comprises:
means for calculating pressure at a wall interface of the at least one heart component at the current time step due to the simulated blood flow in the at least one heart component.
32. The apparatus of claim 31 , wherein the means for calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprises:
means for calculating a deformation of a wall of the at least one heart component due to the pressure at the wall interface of the at least one heart component.
33. The apparatus of claim 29 , wherein the means for calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprises:
means for calculating the deformation of the at least one heart component based on an internal force that models passive properties of the tissue of the at least one heart component and an external force that models loading generated by the blood flow inside the at least one heart component.
34. An apparatus for predictive planning using a comprehensive patient-specific 4D heart model, comprising:
means for generating a comprehensive patient-specific 4D model of the heart from 4D medical imaging data;
means for adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition; and
means for re-generating the comprehensive patient-specific 4D model of the heart to simulate the effect of the adjusted portion on the comprehensive patient-specific 4D model.
35. The apparatus of claim 34 , wherein the means for adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
means for adjusting at least one of an anatomical parameter, a hemodynamic parameter, and a biomechanical parameter of the comprehensive patient-specific 4D model.
36. The apparatus of claim 34 , wherein the means for adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
means for adjusting at least one of an anatomical parameter, a hemodynamic parameter, and a biomechanical parameter of the comprehensive patient-specific 4D model to simulate progression of a disease in the heart.
37. The apparatus of claim 34 , wherein the means for adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprises:
means for adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart.
38. A non-transitory computer readable medium encoded with computer executable instructions for simulating blood flow in the heart based on 4D medical image data, the computer executable instructions defining steps comprising:
generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data; and
simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework, wherein the simulating blood flow comprises:
imposing no-slip boundary conditions to a fluid region of the anatomical model based on a location of a zero level of a level set function used to embed the patient-specific 4D anatomical model in a computational domain.
39. The computer readable medium of claim 38 , wherein the patient-specific 4D anatomical model of the heart comprises a plurality of heart components, and the computer executable instructions defining the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprise computer executable instructions defining the steps of, for each of the plurality of time steps:
calculating convective updates to a level set function and velocity based on the location of the patient-specific 4D anatomical model at the current time step;
calculating a semi-implicit update for the velocity representing a viscous force contribution at the current time step;
calculating a pressure update at the current time step by solving a Poisson equation with Neumann boundary conditions; and
calculating a new velocity update for the current time step based on the semi-implicit velocity update and the pressure update.
40. The computer readable medium of claim 38 , wherein the computer executable instructions defining the step of generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data comprise computer executable instructions defining the step of:
generating a patient specific multi-scale anatomical model of at least one heart component, the multi-scale anatomical model including a coarse anatomical model of the at least one heart component and a fine anatomical model of the at least one heart component.
41. The computer readable medium of claim 40 , wherein the computer executable instructions defining the step of simulating blood flow in the heart by solving Navier-Stokes equations constrained by the patient-specific 4D anatomical model at each of a plurality of time steps in a heart cycle using a level set framework comprise computer executable instructions defining the step of:
simulating the blood flow in the at least one heart component by solving Navier-Stokes equations constrained by the fine anatomical model of the at least one heart component.
42. A non-transitory computer readable medium encoded with computer executable instructions for comprehensive patient-specific modeling of the heart based on 4D medical image data, the computer executable instructions defining steps comprising:
generating a patient-specific 4D anatomical model of the heart from the 4D medical imaging data;
simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework;
calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step; and
repeating the simulating and calculating steps for a plurality of time steps, wherein the current location of the at least one heart component at the current time step is determined at least in part based on the deformation of the at least one heart component calculated at a previous time step.
43. The computer readable medium of claim 42 , further comprising computer executable instructions defining the step of:
comparing the calculated deformation of the at least one heart component with an observed deformation of the at least one heart component in the 4D medical imaging data to determine a biomechanical parameter of the at least one heart component.
44. The computer readable medium of claim 42 , wherein the computer executable instructions defining the step of simulating blood flow in at least one heart component of the patient-specific 4D anatomical model at a current time step by solving Navier-Stokes equations constrained by the location of the at least one heart component at the current time step using a level set framework comprise computer executable instructions defining the step of:
calculating pressure at a wall interface of the at least one heart component at the current time step due to the simulated blood flow in the at least one heart component.
45. The computer readable medium of claim 44 , wherein the computer executable instructions defining the step of calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprise computer executable instructions defining the step of:
calculating a deformation of a wall of the at least one heart component due to the pressure at the wall interface of the at least one heart component.
46. The computer readable medium of claim 42 , wherein the computer executable instructions defining the step of calculating a deformation of the at least one heart component at the current time step based on the simulated blood flow at the current time step comprise computer executable instructions defining the step of:
calculating the deformation of the at least one heart component based on an internal force that models passive properties of the tissue of the at least one heart component and an external force that models loading generated by the blood flow inside the at least one heart component.
47. A non-transitory computer readable medium encoded with computer executable instructions for predictive planning using a comprehensive patient-specific 4D heart model, the computer executable instructions defining steps comprising:
generating a comprehensive patient-specific 4D model of the heart from 4D medical imaging data;
adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition; and
re-generating the comprehensive patient-specific 4D model of the heart to simulate the effect of the adjusted portion on the comprehensive patient-specific 4D model.
48. The computer readable medium of claim 47 , wherein the computer executable instructions defining the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprise computer executable instructions defining the step of:
adjusting at least one of an anatomical parameter, a hemodynamic parameter, and a biomechanical parameter of the comprehensive patient-specific 4D model.
49. The computer readable medium of claim 47 , wherein the computer executable instructions defining the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprise computer executable instructions defining the step of:
adjusting at least one of an anatomical parameter, a hemodynamic parameter, and a biomechanical parameter of the comprehensive patient-specific 4D model to simulate progression of a disease in the heart.
50. The computer readable medium of claim 47 , wherein the computer executable instructions defining the step of adjusting a portion of the comprehensive patient-specific 4D model to simulate a condition comprise computer executable instructions defining the step of:
adjusting a portion of the comprehensive patient-specific 4D model to virtually simulate applying a therapy to a corresponding portion of the heart.