Method and system for functional assessment of renal artery stenosis from medical images

Patent metadata

Field	Value
Publication number	US-9629563-B2
Application number	US-201414477770-A
Country	US
Kind code	B2
Filing date	Sep 4, 2014
Priority date	Sep 4, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method and system for non-invasive assessment of renal artery stenosis is disclosed. A patient-specific anatomical model of at least a portion of the renal arteries and aorta is generated from medical image data of a patient. Patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta are estimated based on the patient-specific anatomical model. Blood flow and pressure are simulated in the portion of the renal arteries and aorta using the computational model based on the patient-specific boundary conditions. At least one hemodynamic quantity characterizing functional severity of a renal stenosis region is calculated based on the simulated blood flow and pressure in the portion of the renal arteries and aorta.

First claim

The invention claimed is:

1. A method for assessment of renal artery stenosis, comprising:
generating a patient-specific anatomical model of at least a portion of the renal arteries and aorta from medical image data of a patient;
estimating patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta based on the patient-specific anatomical model;
simulating blood flow and pressure in the portion of the renal arteries and aorta using the computational model based on the patient-specific boundary conditions; and
calculating at least one hemodynamic quantity characterizing functional severity of a renal stenosis region based on the simulated blood flow and pressure in the portion of the renal arteries and aorta,
wherein the computational model comprises a reduced order stenosis pressure-drop model representing the renal stenosis region coupled to a one-dimensional computational model representing a renal artery and the reduced order stenosis pressure-drop model calculates a pressure drop across the renal stenosis region as a sum of a viscous term, a turbulent term, and an inertance term.

2. The method of claim 1 , further comprising:
quantifying at least one inflow and at least one outflow to the portion of the renal arteries and aorta.

3. The method of claim 2 , wherein estimating patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta based on the patient-specific anatomical model comprises:
determining inlet and outlet boundary conditions using the quantified at least one inflow and at least one outflow to the portion of the renal arteries and aorta.

4. The method of claim 2 , wherein quantifying at least one inflow and at least one outflow to the portion of the renal arteries and aorta comprises:
measuring flow rates in each of a plurality of 2D flow slices corresponding to inlet and outlet positions of the portion of the renal arteries and aorta.

5. The method of claim 4 , wherein the plurality of 2D flow slices comprise a first 2D flow slice that is a supra-renal cross-section of the aorta, a second 2D flow slice that is a infra-renal cross-section of the aorta, a third 2D flow slice that is a cross-section of a target renal artery distal to the renal stenosis region, and a fourth 2D flow slice that is a cross-section of a non-target renal artery.

6. The method of claim 4 , wherein each of the plurality of 2D flow slices is a 2D phase-contrast magnetic resonance imaging (PCMRI) image.

7. The method of claim 2 , wherein quantifying at least one inflow and at least one outflow to the portion of the renal arteries and aorta comprises:
masking a flow image of the patient using the patient-specific anatomical model to obtain flow information in a lumen of the portion of the renal arteries and aorta.

8. The method of claim 1 , wherein estimating patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta based on the patient-specific anatomical model comprises:
estimating patient-specific boundary conditions of the computational model for a plurality of physiological states of the patient.

9. The method of claim 8 , wherein estimating patient-specific boundary conditions of the computational model for a plurality of physiological states of the patient comprises:
estimating the patient-specific boundary conditions for each of the plurality of physiological states based on a respective patient-specific anatomic model extracted from medical image data acquired at each of the plurality of physiological states.

10. The method of claim 8 , wherein estimating patient-specific boundary conditions of the computational model for a plurality of physiological states of the patient comprises:
estimating patient-specific boundary conditions for a rest state based on the patient-specific anatomical model extracted from medical image data acquired at a rest state; and
estimating patient-specific boundary conditions for a hyperemic state based on the estimated patient-specific boundary conditions for the rest state.

11. The method of claim 1 , wherein calculating at least one hemodynamic quantity characterizing functional severity of a renal stenosis region based on the simulated blood flow and pressure in the portion of the renal arteries and aorta comprises:
calculating a pressure drop across the renal stenosis region based on the simulated blood flow and pressure.

12. The method of claim 1 , wherein calculating at least one hemodynamic quantity characterizing functional severity of a renal stenosis region based on the simulated blood flow and pressure in the portion of the renal arteries and aorta comprises:
calculating fractional flow reserve (FFR) for the renal stenosis region based on the simulated blood flow and pressure.

13. The method of claim 1 , wherein computational model comprises one-dimensional computational models representing the renal arteries and aorta of the patient.

14. The method of claim 1 , wherein the computational model comprises lumped models representing microvascular beds, each coupled to a termination of a one-dimensional computational model representing a respective renal artery.

15. An apparatus for assessment of renal artery stenosis, comprising:
a processor; and
a memory storing computer program instructions, which when executed by the processor cause the processor to perform operations comprising:
generating a patient-specific anatomical model of at least a portion of the renal arteries and aorta from medical image data of a patient;
estimating patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta based on the patient-specific anatomical model;
simulating blood flow and pressure in the portion of the renal arteries and aorta using the computational model based on the patient-specific boundary conditions; and
calculating at least one hemodynamic quantity characterizing functional severity of a renal stenosis region based on the simulated blood flow and pressure in the portion of the renal arteries and aorta,

wherein the computational model comprises a reduced order stenosis pressure-drop model representing the renal stenosis region coupled to a one-dimensional computational model representing a renal artery and the reduced order stenosis pressure-drop model calculates a pressure drop across the renal stenosis region as a sum of a viscous term, a turbulent term, and an inertance term.

16. The apparatus of claim 15 , wherein the operations further comprise:
quantifying at least one inflow and at least one outflow to the portion of the renal arteries and aorta.

17. The apparatus of claim 16 , wherein estimating patient-specific boundary conditions of a computational model of blood flow in the portion of the renal arteries and aorta based on the patient-specific anatomical model comprises:
determining inlet and outlet boundary conditions using the quantified at least one inflow and at least one outflow to the portion of the renal arteries and aorta.

18. The apparatus of claim 16 , wherein quantifying at least one inflow and at least one outflow to the portion of the renal arteries and aorta comprises:
measuring flow rates in each of a plurality of 2D flow slices corresponding to inlet and outlet positions of the portion of the renal arteries and aorta.

19. The apparatus of claim 18 , wherein the plurality of 2D flow slices comprise a

Assignees

• Sharma Puneet
• Rapaka Saikiran
• Mihalef Viorel
• Kamen Ali
• Siemens Healthcare Gmbh

Inventors

• Sharma Puneet
• Rapaka Saikiran
• Mihalef Viorel
• Kamen Ali

Classifications

• G01R33/5635

  Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA] · CPC title

• G01R33/56316

  involving phase contrast techniques · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title

• A61B5/021

  Measuring pressure in heart or blood vessels · CPC title

• A61B5/055

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title