Non-invasive systems and methods for determining fractional flow reserve

Patent metadata

Field	Value
Publication number	US-9974508-B2
Application number	US-201213603073-A
Country	US
Kind code	B2
Filing date	Sep 4, 2012
Priority date	Sep 1, 2011
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Non-invasive systems and methods for determining fractional flow reserve. At least one method of determining fractional flow reserve within a luminal organ of the present disclosure comprising the steps of positioning a monitoring device external to a luminal organ and near a stenosis, the monitoring device capable of determining at least one characteristic of the stenosis, operating the monitoring device to determine the at least one characteristic of the stenosis, and determining fractional flow reserve at or near the stenosis based upon the at least one characteristic determined by the monitoring device.

First claim

What is claimed is:

1. A non-invasive method for determining fractional flow reserve within a luminal organ, the method comprising the steps of:
positioning a monitoring device external to a luminal organ at or near a stenosis, the monitoring device capable of determining at least one characteristic of the stenosis from such position, the monitoring device comprising an angiography device using angiography to determine the at least one characteristic of the stenosis;
operating the monitoring device to obtain a medical image of the luminal organ at or near the stenosis and noninvasively identify at least one characteristic of the stenosis directly from the medical image;
determining fractional flow reserve at or near the stenosis based upon at least the at least one characteristic identified by the monitoring device;
wherein the step of determining fractional flow reserve comprises the step of:
computing the fractional flow reserve using a data acquisition and processing system using an algorithm selected from the group consisting of the equation:

Δ
⁢

⁢
P

=

ρ
⁢

⁢

Q
2

2

⁢

(

1

CSA
outlet
2

-

1

CSA
inlet
2

)

+

Δ
⁢

⁢

P
diffusive

+

Δ
⁢

⁢

P
expansion

;

the equation:

FFR
=

P
distal

P
a

=

P
a

-

Δ
⁢

⁢
P

P
a

;

a combination thereof, and a mathematical equivalent of any of the aforementioned equations; and

wherein ΔP is a pressure gradient along an axis of a segment of the luminal organ from a proximal position to a distal position of the stenosis, ρ is a density of blood, Q is a hyperemic flow rate in the segment of the luminal organ determined based on an analytical model, CSA outlet is an outlet cross-sectional area, CSA inlet is an inlet cross-sectional area, ΔP diffusive is a diffusive energy loss, and ΔP expansion is an energy loss due to enlargement in cross-sectional area from the stenosis to a distal normal vessel segment, FFR is the fractional flow reserve, P a is a mean aortic pressure, and P distal is a hyperemic coronary pressure distal to the stenosis;
assessing hemodynamic function of the luminal organ based on the fractional flow reserve at or near the stenosis computed using the algorithm by comparing the computed fractional flow reserve to a comparison value in a database to determine the degree of stenosis; and
treating the stenosis if the hemodynamic function assessed by computing the fractional flow reserve using the algorithm and comparing the fractional flow reserve to the comparison value in the database indicates the stenosis is functionally significant.

2. The method of claim 1 , wherein the at least one characteristic is selected from the group consisting of a stenosis geometry and a flow rate in the vessel at or near the stenosis.

3. The method of claim 2 , wherein the stenosis geometry comprises at least one geometry selected from the group consisting of a cross-sectional area of the luminal organ distal to the stenosis, a cross-sectional area of the luminal organ proximal to the stenosis, at least one cross-sectional area of the luminal organ at the stenosis, a percentage maximum stenosis of the luminal organ, and the length of the lesion of the luminal organ.

4. The method of claim 1 , further comprising the step of:
diagnosing a disease based upon the determination of the fractional flow reserve within the vessel; and
wherein the step of determining fractional flow reserve at or near the stenosis is performed in less than about 2 minutes.

5. The method of claim 1 , wherein the determination of fractional flow reserve is indicative of a degree of stenosis within the luminal organ.

6. The method of claim 1 , wherein the step of determining fractional flow reserve is performed using a data acquisition and processing system in communication with the database containing one or more variables relating to the stenosis.

7. The method of claim 6 , wherein the database contains a comparison value, and wherein the method further comprises the step of:
diagnosing a disease by comparing the determined fractional flow reserve to the comparison value.

8. The method of claim 1 , wherein:
the monitoring device operates to noninvasively identify the at least one stenosis characteristic through angiography; and
the hyperemic flow rate is determined from a flow-diameter scaling law directly using an equation:

Resistance
=

99
×
1333.22

10
×

D
s

Assignees

• Kassab Ghassan S
• Huo Yunlong

Inventors

• Kassab Ghassan S
• Huo Yunlong

Classifications

• A61B6/507

  for determination of haemodynamic parameters, e.g. perfusion CT · CPC title

• A61B5/02007

  Evaluating blood vessel condition, e.g. elasticity, compliance · CPC title

• A61B6/5217

  extracting a diagnostic or physiological parameter from medical diagnostic data · CPC title

• A61B5/0263

  using NMR · CPC title

• A61B6/504 Primary

  for diagnosis of blood vessels, e.g. by angiography · CPC title