METHODS FOR THE NON-INVASIVE DETERMINATION OF HEART AND PULMONARY PRESSURES

• US 20140275961A1
• Filed: 03/16/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Ghassan S. Kassab, Yunlong Huo
• Original Assignee: Ghassan S. Kassab, Yunlong Huo
• Inventors: Kassab, Ghassan S., Huo, Yunlong
• Granted Patent: US 10,390,713 B2
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: A61B 5/02133 by using induced vibration of the blood vessel
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/0263 using NMR
• CPC Class Codes: A61B 5/0265 using electromagnetic means, e.g. electromagnetic flowmeter
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/0883 for diagnosis of the heart
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: G01R 33/20 involving magnetic resonance medical aspects A61B5/055; magnetic resonance gyrometers G01C19/60
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

The disclosure of the present application provides methods for the noninvasive determination of cardiac and pulmonary pressures based off of patient-specific medical images and one or more computations. In one exemplary embodiment, the method comprises noninvasively generating a patient-specific medical image of at least a portion of a heart, determining a free vibration measurement from the left ventricular free wall based on the patient-specific image, and performing at least one computation using the free vibration measurement to noninvasively determine a cardiac or pulmonary pressure.

Claims

1. A method for noninvasively determining one or more pressure measurements comprising the steps of:

generating a patient-specific medical image of at least one portion of a heart of a patient noninvasively;

determining at least one measurement from a portion of the heart in the patient-specific medical image; and

performing one or more computations using the measurement to noninvasively determine at least one targeted pressure within one or more portions of the heart and/or an adjacent vessel.

2. The method of claim 1, wherein one of the at least one measurements comprises a free vibration measurement.

3. The method of claim 1, wherein the targeted pressure is selected from the group consisting of a left ventricle end-diastolic pressure, a right ventricle pressure, and a pulmonary pressure.

4. The method of claim 1, wherein the patient-specific medical image of at least a portion of the heart is generated through magnetic resonance imaging or echocardiography.

5. The method of claim 2, wherein:

the free vibration measurement is obtained from a free wall of a left ventricle of the heart; and

at least one of the computations is for determining end-diastolic Young'"'"'s modulus of the left ventricular free wall using the free vibration measurement.

6. The method of claim 5, wherein at least one of the computations is for determining patient-specific material parameters of the heart in diastolic strain energy function through numerical optimization (inverse method) such that a Young'"'"'s modulus value from strain energy function is substantially equal to the value of the end-diastolic Young'"'"'s modulus of the left ventricular free wall determined from the free vibration measurement.

7. The method of claim 6, wherein:

at least one of the measurements determined from the patient-specific medical image relates to the position of the left ventricular free wall;

the at least one targeted pressure comprises a left ventricular end-diastolic pressure; and

at least one of the computations is for determining the left ventricular end-diastolic pressure by iterative solution such that a predicted left ventricular free wall position substantially matches the measurements related to the position of the left ventricular free wall.

8. The method of claim 7, wherein:

at least one of the measurements determined from the patient-specific medical image relates to the position of a interventricular septum; and

at least one of the computations is for determining right ventricular end-diastolic pressure by iterative solution such that a predicted end-diastolic interventricular septum position substantially matches the measurements related to the position of the interventricular septum.

9. The method of claim 6, further comprising the step of determining left ventricular systolic pressure by noninvasively measuring aortic pressure;

left ventricular systolic pressure being substantially equivalent to aortic pressure.

10. The method of claim 9, wherein:

at least one of the measurements determined from the patient-specific medical image relates to the position of the left ventricle systolic free wall;

at least one of the targeted pressures comprises right ventricular systolic pressure; and

at least one of the computations is for determining patient-specific material parameters of the heart in systolic second Piola-Kirchhoff stress by numerical optimization (inverse method) such that a predicted left ventricle systolic free wall position substantially matches the measurements related to the position of the left ventricle systolic free wall.

11. The method of claim 10, wherein:

at least one of the measurements determined from the patient-specific medical image relates to the position of a systolic interventricular septum; and

at least one of the targeted pressures comprises right ventricular systolic pressure; and

at least one of the computations is for determining right ventricular systolic pressure by iterative solution such that a predicted systolic interventricular septum position substantially matches the measurements related to the position of the systolic interventricular septum.

12. The method of claim 11, further comprising the step of calculating a blood flow velocity and determining a pressure gradient from the blood flow velocity, and wherein at least one of the targeted pressures comprises pulmonary pressure derived from the right ventricular systolic pressure and the pressure gradient.

13. The method of claim 12, wherein the pressure gradient is determined from magnetic resonance imaging blood flow velocity measurements through a right ventricle of the heart.

14. The method of claim 13, further comprising the steps of:

noninvasively determining venous pressure; and

using the venous pressure as reference for determining and/or validating the pressure gradient.

15. The method of claim 1, further comprising the steps of:

determining a pressure gradient based on blood flow velocity measurements obtained from the patient-specific medical image;

determining left ventricular systolic pressure by noninvasively measuring aortic pressure, left ventricular systolic pressure being substantially equivalent to aortic pressure; and

assessing the pressure difference across an interventricular septum in view of the left ventricular systolic pressure to determine right ventricular systolic pressure.

16. A method for noninvasively determining right ventricular systolic pressure comprising the steps of:

determining a pressure gradient based on blood flow velocity measurements through the right ventricle of a heart;

determining left ventricular systolic pressure by noninvasively measuring aortic pressure; and

assessing the pressure difference across an interventricular septum in view of the left ventricular systolic pressure to determine right ventricular systolic pressure.

17. The method of claim 16, wherein the blood flow velocity measurements are achieved through magnetic resistance imaging.

18. The method of claim 16, wherein the aortic pressure is obtained through blood pressure cuff measurements.

19. The method of claim 16, further comprising the steps of:

noninvasively determining venous pressure; and

using the venous pressure as reference for determining and/or validating the pressure gradient.

20. A method for noninvasively determining one or more cardiac pressure measurements comprising the steps of:

generating a patient-specific medical image of at least one portion of a heart noninvasively through magnetic resonance imaging or external ultrasound;

obtaining at least one measurement related to the position of the left ventricular free wall and the interventricular septum from the patient-specific medical image;

determining at least a free vibration measurement from a free wall of a left ventricle of the heart in the patient-specific medical image;

determining end-diastolic Young'"'"'s modulus of the left ventricular free wall using the free vibration measurement;

determining patient-specific material parameters of the heart in diastolic strain energy function through numerical optimization (inverse method) such that a Young'"'"'s modulus value from strain energy function is derived that is substantially equal to the value of the end-diastolic Young'"'"'s modulus of the left ventricular free wall determined from the free vibration measurement;

determining the left ventricular end-diastolic pressure by iterative solution such that a predicted left ventricular free wall position substantially matches the measurements related to the left ventricular free wall position; and

determining right ventricular end-diastolic pressure by iterative solution such that a predicted end-diastolic interventricular septum position substantially matches the measurements related to the position of the interventricular septum.