Method and system for patient-specific modeling of blood flow
Embodiments include a system for determining cardiovascular information for a patient. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart, and create a three-dimensional model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create a physics-based model relating to a blood flow characteristic of the patient's heart and determine a fractional flow reserve within the patient's heart based on the three-dimensional model and the physics-based model.
1. A system for evaluating cardiovascular treatment options for a patient, the system comprising:
at least one data storage device storing instructions for evaluating cardiovascular treatment options for a patient; and
at least one processor configured to execute the instructions to perform operations comprising:
receiving a three-dimensional model representing at least a portion of the patient's heart or vasculature based on patient-specific data regarding a geometry of the patient's heart or vasculature, the portion of the patient's heart or vasculature having a patient-specific stenosis or diseased area, the three-dimensional model representing at least the portion of the patient's heart or vasculature including a representation of at least a portion of the patient's blood vessels;
removing and replacing a portion of the three-dimensional model with a patient-specific reduced order model of blood flow, the patient-specific reduced order model comprising a one-dimensional or two-dimensional model and including a plurality of segments, the plurality of segments including a segment modeling the patient-specific stenosis or diseased area, each segment represented by a respective component having one or more values of a linear resistance, a non-linear resistance, a capacitance, or an inductance, the one or more values representative of one or more of:
a resistance to blood flow of the segment;
an elasticity of vessel walls of the segment; or
inertial effects related to one or more of acceleration or deceleration of blood flow through the segment;
for each of a plurality of treatment options, determining a size of the treatment option or a location of the three-dimensional model associated with the treatment option;
for each of the plurality of treatment options, determining a modification to the one or more values of the component of at least one segment of the patient-specific reduced order model based on the determined size or the determined location of the treatment option, the modification representing the treatment option;
for each of the plurality of treatment options, applying the determined modification of the one or more values to the component of the at least one segment of the patient-specific reduced order model to thereby determine a respective modified patient-specific reduced order model modeling an application of the treatment option to the portion of the patient's heart or vasculature;
determining respective values of a blood flow characteristic of the modified patient-specific reduced order models; and
based on the determined values of the blood flow characteristic, identifying one of the plurality of treatment options that solves an optimization model having an objective function of at least the blood flow characteristic.
2. The system of claim 1 , the operations further comprising modifying the three-dimensional model for a subset of each of the plurality of treatment options in locations that exhibit a hemodynamic significance.
3. The system of claim 1 , wherein:
the blood flow characteristic indicates a ratio between a pressure in a blood vessel and a pressure at a location in a plurality of branched vessels of said blood vessel; and
the operations further comprise determining the blood flow characteristic at a plurality of locations in the plurality of branched vessels of said blood vessel.
4. The system of claim 1 , wherein the patient-specific data includes imaging data provided by computer tomography or magnetic resonance imaging techniques.
5. The system of claim 1 , wherein the patient-specific reduced order model includes at least one lumped parameter model representing a blood flow through boundaries of the three-dimensional model.
6. The system of claim 1 , wherein the at least one processor is configured to determine the blood flow characteristic using a parameter associated with at least one of a level of hyperemia, a level of exercise, or a medication.
7. The system of claim 1 , wherein
the optimization model is based on the modified patient-specific reduced order models respectively obtained for the plurality of treatment options, the values of the blood flow characteristic respectively determined for the plurality of treatment options, and costs respectively associated the plurality of treatment options, and
a solution of the determined optimization model is a treatment option that is, according to the objective function, optimal among the plurality of treatment options for a combination of (1) maximizing blood flow in a patient's vasculature, (2) minimizing pressure changes in a patient's vasculature, and (3) minimizing a cost associated with the identified treatment option.
8. The system of claim 1 , the operations further comprising:
dividing the three-dimensional model into a plurality of three-dimensional-model segments;
for each of the plurality of three-dimensional-model segments, determining a respective component having one or more values to represent the three-dimensional-model segment based on whether the three-dimensional-model segment includes a representation of the patient-specific stenosis or diseased area; and
determining the patient-specific reduced order model so that the plurality of segments of the patient-specific reduced order model are respectively defined by the one or more values of the components determined for the plurality of three-dimensional-model segments.
9. The system of claim 1 , wherein, to modify the patient-specific reduced order model based on the determined modification respectively representing the treatment option to thereby determine the respective modified patient-specific reduced order model, the at least one processor is configured to:
apply the one or more values of the determined modification representing the treatment option to the component representative of one of the plurality of segments of the patient-specific reduced order model or to a component of a new segment of the patient-specific reduced order model.
10. The system of claim 1 , wherein the component representing each segment has:
at least one of a linear resistance value or a non-linear resistance value that is representative of the resistance to blood flow of the segment;
a capacitance value representative of the elasticity of the vessel walls of the segment; and
an inductance value representative of the inertial effects related to one or more of acceleration or deceleration of blood flow through the segment.
11. A method for evaluating cardiovascular treatment options for a patient, the method comprising:
receiving a three-dimensional model representing at least a portion of the patient's heart or vasculature based on patient-specific data regarding a geometry of the patient's heart or vasculature, the portion of the patient's heart or vasculature having a patient-specific stenosis or diseased area, the three-dimensional model representing at least the portion of the patient's heart or vasculature including a representation of at least a portion of the patient's blood vessels;
removing and replacing a portion of the three-dimensional model with a patient-specific reduced order model of blood flow, the patient-specific reduced order model comprising a one-dimensional or two-dimensional model and including a plurality of segments, the plurality of segments including a segment modeling the patient-specific stenosis or diseased area, each segment represented by a respective component having one or more values of a linear resistance, a non-linear resistance, a capacitance, or an inductance, the one or more values representative of one or more of:
a resistance to blood flow of the segment;
an elasticity of vessel walls of the segment; or
inertial effects related to one or more of acceleration or deceleration of blood flow through the segment;
for each of a plurality of treatment options, determining a size of the treatment option or a location of the three-dimensional model associated with the treatment option;
for each of the plurality of treatment options, determining a modification to the one or more values of the component of at least one segment of the patient-specific reduced order model based on the determined size or the determined location of the treatment option, the modification representing the treatment option;
for each of the plurality of treatment options, applying the determined modification of the one or more values to the component of the at least one segment of the patient-specific reduced order model to thereby determine a respective modified patient-specific reduced order model modeling an application of the treatment option to the portion of the patient's heart or vasculature;
determining respective values of a blood flow characteristic of the modified patient-specific reduced order models; and
based on the determined values of the blood flow characteristic, identifying one of the plurality of treatment options that solves an optimization model having an objective function of at least the blood flow characteristic.
12. The method of claim 11 , further comprising modifying the three-dimensional model for a subset of each of the plurality of treatment options in locations that exhibit a hemodynamic significance.
13. The method of claim 11 , wherein:
the blood flow characteristic indicates a ratio between a pressure in a blood vessel and a pressure at a location in a plurality of branched vessels of said blood vessel; and
the method comprises determining the blood flow characteristic at a plurality of locations in the plurality of branched vessels of said blood vessel.
14. The method of claim 11 , wherein the patient-specific data includes imaging data provided by computer tomography or magnetic resonance imaging techniques.
15. The method of claim 11 , wherein the patient-specific reduced order model includes at least one lumped parameter model representing a blood flow through boundaries of the three-dimensional model.
16. The method of claim 11 , further comprising determining the blood flow characteristic using a parameter associated with at least one of a level of hyperemia, a level of exercise, or a medication.
17. The method of claim 11 , wherein
the optimization model is based on the modified patient-specific reduced order models respectively obtained for the plurality of treatment options, the values of the blood flow characteristic respectively determined for the plurality of treatment options, and costs respectively associated the plurality of treatment options, and
a solution of the determined optimization model is a treatment option that is, according to the objective function, optimal among the plurality of treatment options for a combination of (1) maximizing blood flow in a patient's vasculature, (2) minimizing pressure changes in a patient's vasculature, and (3) minimizing a cost associated with the identified treatment option.
18. The method of claim 11 , wherein the removing and replacing of the portion of the patient-specific reduced order model comprises:
dividing the three-dimensional model into a plurality of three-dimensional-model segments;
for each of the plurality of three-dimensional-model segments, determining a respective component having one or more values to represent the three-dimensional-model segment based on whether the three-dimensional-model segment includes a representation of the patient-specific stenosis or diseased area; and
determining the patient-specific reduced order model so that the plurality of segments of the patient-specific reduced order model are respectively defined by the one or more values of the components determined for the plurality of three-dimensional-model segments.
19. The method of claim 11 , wherein modifying the patient-specific reduced order model based on the determined modification respectively representing the treatment option to thereby determine the respective modified patient-specific reduced order model comprises:
applying the one or more values of the determined modification representing the treatment option to the component representative of one of the plurality of segments of the patient-specific reduced order model or to a component of a new segment of the patient-specific reduced order model.
20. The method of claim 11 , wherein the component representing each segment has:
at least one of a linear resistance value or a non-linear resistance value that is representative of the resistance to blood flow of the segment;
a capacitance value representative of the elasticity of the vessel walls of the segment; and
an inductance value representative of the inertial effects related to one or more of acceleration or deceleration of blood flow through the segment.