SHAPE Society

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Intravascular Elastography:
palpating plaques with the finger of IVUS
C.L. de Korte1
, F. Mastik1
, J.A. Schaar1
,
M. Sierevogel1,3
,G. Pasterkamp3
,
P.W. Serruys1
and A.F.W van der Steen1,2
1
Erasmus University, Thoraxcentre, Rotterdam, The Netherlands
2
Interuniversity Cardiology Institute of the Netherlands
3
Experimental Cardiology Laboratory, University Medical Center, Utrecht, The Netherlands
Supported by Netherlands Organization for Scientific Research (NWO)
and the Dutch Technology Foundation (STW)

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Background : Vulnerable plaque
que vulnerability :
que composition
• Large lipid pool
Mechanical
properties
• High strain region
• Thin fibrous cap
• presence of Macrophages

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Background : Principle of elastography
Soft Harduncompressed
compressed
• The response of tissue to mechanical excitation (e.g.
compression) is a function of its mechanical
properties.
Force Soft Hard

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IVUS elastography
(t1, P1)
(t2,P2)
Processing
IVUS at 100mmHg
IVUS at 80mmHg
IVUS elastogram
strain
1%
0%

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strain
1%
0%
Picrosirius-red Anti-CD68 antibodyAlpha-actin
Circulation 102(6) 617-623 (2000)
IVUS elastography plaque characterization

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strain
1%
0%
Picrosirius-red Anti-CD68 antibodyAlpha-actin
IVUS elastography vulnerable plaque detection
ACC 2002, presentation 1054-20

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Predictive power of elastography
to identify the vulnerable plaque
1 - Specificity
1.00.75.50.25
Sensitivity
1.00
.75
.50
.25
0
Strain 1.26 %:
Sensitivity 88%
Specificity 89%
ACC 2002, presentation 1054-20

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0 20 40 60 80 100 120
40
60
80
100
120
140
Frame no.
Intra-coronary
pressure[mmHg]
In vivo elastography
Strain [%]
1.0
0.0
Eur Heart J 23(5): 405-413 (2002)

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Cross-section LAD of patient with U.A.P
Strain [%]
2.0
0.0

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IVUS elastography before atherectomy
Strain [%]
1.0
0.0

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Fibrous cap tissue
Fibro-fatty core tissue
Histology atherectomy specimen

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Echogram and elastogram obtained in vivo in Yucatan
strain
1%
0%
Elastic-von Giesson Picro-Sirius red Acid Phosphatase
Polarized light
Circulation (2002) in press

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Tissue mean std
Normal segments (n=6) 0.21 0.09
Early fatty lesion (n=9) 0.46 0.17
Early fibrous lesion (n=3) 0.24 0.03
Advanced fibrous lesion (n=6) 0.22 0.04
Strain [%]
*
Strain and plaque composition in Yucatan
Univariate ANOVA on strain
Fat p=0.007
MΦ p=0.966
1 - Specificity
1.00.75.50.250.00
Sensitivity
1.00
.75
.50
.25
0.00
Area=0.952
Circulation (2002) in press

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3 Dimensional Elastography

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Conclusion
Intravascular Ultrasound Elastography:
A powerful technique to identify
the vulnerable plaque.