image functional modeling: combining lung models with imaging modalities and mechanical measures...
Post on 19-Dec-2015
215 views
TRANSCRIPT
![Page 1: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/1.jpg)
Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures
Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,
Allison Bell, and K. R. Lutchen
October 14, 2004
BMES Conference
![Page 2: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/2.jpg)
Stimuli Cell activation Inflammatorymediators
Airway Changes
Airway Obstruction
(Allergens,outdoor pollutants and viruses)
(mast cells, eosinophils, neutrophils)
Size and Location Distribution
? ?
(proinflammatory mediators: histamine)
(inflammation, remodeling, bronchoconstriction)
Asthma
http://www.merckfrosst.ca/e/health/asthma/sum_01.html
![Page 3: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/3.jpg)
Mechanical Heterogeneity in Asthma
Which airways are most responsible for degradation inWhich airways are most responsible for degradation in function and hyperresponsiveness?function and hyperresponsiveness?
![Page 4: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/4.jpg)
Apnea
Time (secs)
Washout
PET Imaging: Tracer Kinetics
![Page 5: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/5.jpg)
Apnea
Time (secs)
Washout
PET Imaging: Tracer Kinetics
![Page 6: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/6.jpg)
PET Imaging
apex
base
Images from Mass General Hospital
Pre Challenge Post Challenge
![Page 7: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/7.jpg)
Hyperpolarized 3He MRI Imaging
Images from Brigham and Women’s Hospital
Pre Challenge Post Challenge
![Page 8: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/8.jpg)
Image-Functional Modeling (IFM)
Goal:
To synthesize the imaging and mechanical information in To synthesize the imaging and mechanical information in order to identify which airways are responsible for the order to identify which airways are responsible for the degradation in the mechanics and ventilation distribution on a degradation in the mechanics and ventilation distribution on a patient specific basis. patient specific basis.
Method:
Combine the imaging and mechanical data with 3D anatomically Combine the imaging and mechanical data with 3D anatomically consistent multi-scale lung models. consistent multi-scale lung models.
![Page 9: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/9.jpg)
Advancing 3D Models for Computation of Mechanical Function
Zw(n)
Z(n-1)
Z(n-1- )
Z(n) R(n)/2 I(n)/2
Cg(n)
R(n)/2 I(n)/2
• Impedance of a Single Airway
• Airways Terminate on Alveoli with Viscoelastic Tissue
Tawhai et al, 1999
![Page 10: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/10.jpg)
IFM:Mapping PET Ventilation Defects into 3D Model
Post Washout:Tracer Retention
Pre Washout:Baseline
![Page 11: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/11.jpg)
d < 2.5 mm
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
Baseline
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenge
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged< 0.6 mm
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged< 0.9mmd< 0.6 mm
Frequency (Hz)
Size Range of Allowable Closed Airways: 0.3-2.5 mm.Size Range of Allowable Closed Airways: 0.3-2.5 mm.
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged<2.5 mmd< 0.9mmd< 0.6 mm
Frequency (Hz)
d< .9 mm
PET: IFM Application
0 closed
100 open
Percent of Baseline Airway Diameter
80
60
40
20
d <.6 mm
![Page 12: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/12.jpg)
Hyperpolarized MRI : IFM Application
![Page 13: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/13.jpg)
2
1.6
1.2
.8
.4
0
Ventilation Spectrum: Fraction of Baseline Ventilation
normal
over
under
PET Based Model Based
Image and Model Based Ventilation Images
![Page 14: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/14.jpg)
Summary
We identified constriction conditions, which are consistent with both the lung mechanics and imaging information for 4 asthmatics:
Maximum airway size for closures: 0.9 -2.4 mmMean airway sizes affected: <1 mm and belowConstriction Conditions: = 60% , SD= 20%
The IFM paradigm provides a platform for multi-scale sensitivity analysis regarding how the integrated components of lung structure determined the degradation in function during airway disease.
![Page 15: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/15.jpg)
AcknowledgementsAnesthesia & Critical Care,MGH
Jose G. Venegas
R. Scott Harris
Marcos Vidal Melo
Guido Musch
Tilo Winkler
Giacomo Bellani
BU Respiratory Lab
Kenneth R. Lutchen
Carissa Bellardine
Derek Affonce
Brian Szender
Allison Bell
Mike Hamilton
Jen Kenyon
Adam LaPrad
University of Auckland, New ZealandMerryn Tawhai
Brigham and Women’s HospitalMitchell AlbertYang- Sheng Tzeng
Funding Sources
AAUW Selected Professions FellowshipNIHBMES
![Page 16: Image Functional Modeling: Combining Lung Models with Imaging Modalities and Mechanical Measures Nora T. Tgavalekos, Jose G. Venegas, Mitchell Albert,](https://reader035.vdocuments.us/reader035/viewer/2022081519/56649d3b5503460f94a1616f/html5/thumbnails/16.jpg)
PET: IFM Application
d < 2.5 mm
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
Baseline
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenge
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged< 0.6 mm
Frequency (Hz)
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged< 0.9mmd< 0.6 mm
Frequency (Hz)
Size Range of Allowable Closed Airways: 0.3-2.5 mm.Size Range of Allowable Closed Airways: 0.3-2.5 mm.
0 2 4 6 8
Res
ista
nce(
cmH
20/l/
s)
0
9
18
27
36
45
0 2 4 6 8
Ela
stan
ce(c
mH
20/l)
0
100
200
300
BaselinePost Challenged<2.5 mmd< 0.9mmd< 0.6 mm
Frequency (Hz)
d< .9 mm
100 open
Percent of Baseline Airway Diameter
80
60
40
20
0 closed
d <.6 mm