SHAPE Society

1. CdK ‘02
ICIN
Intravascular Elastography:
from Bench to Bedside
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)

2. CdK ‘02
ICIN
Background : Vulnerable plaque
que vulnerability :
que composition
• Large lipid pool
Mechanical
properties
• High strain region
• Thin fibrous cap
• presence of Macrophages

3. CdK ‘02
ICIN
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

4. CdK ‘02
ICIN
IVUS elastography
(t1, P1)
(t2,P2)
Processing
IVUS at 100mmHg
IVUS at 80mmHg
IVUS elastogram
strain
1%
0%

5. CdK ‘02
ICIN
strain
1%
0%
Picrosirius-red Anti-CD68 antibodyAlpha-actin
Circulation 102(6) 617-623 (2000)
IVUS elastography plaque characterization

6. CdK ‘02
ICIN
Vulnerable plaque detection
In vitro 25 human coronary arteries with
78 cross-sections.
Histology:
• lipid core (> 40%)
• thin cap with moderate/heavy macrophage infiltration
Elastography:
• high strain region on the surface of the plaque
• an adjacent low strain region
Definition used for plaque
Vulnerability :

7. CdK ‘02
ICIN
strain
1%
0%
Picrosirius-red Anti-CD68 antibodyAlpha-actin
IVUS elastography vulnerable plaque detection
Circulation 104 (17): II-459 (2001)

8. CdK ‘02
ICIN
sensitivity specificity
Sensitivity and Specificity
3
0
0 0.5 1 1.5 2 2.5
Strain [%]
1
Strain 1.26 %: Sensitivity 88%
Specificity 89%
Circulation 104 (17): II-459 (2001)

9. CdK ‘02
ICIN
IVUS elastography in patients
• Patients referred for Percutaneous Coronary intervention
• Pre intervention IVUS assessment of the culprit lesion
using 20 MHz JOMED Avanar®
IVUS catheter.
• JOMED InVision Gold Echo system with digital
acquisition system for off-line processing
• Find phase of heart-cycle with minimal motion of
catheter since motion decreases elastographic quality.

10. CdK ‘02
ICIN
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)

11. CdK ‘02
ICIN
Cross-section LAD of patient with U.A.P
Strain [%]
2.0
0.0

12. CdK ‘02
ICIN
Patient with Angina Pectoris
Strain [%]
1.0
0.0

13. CdK ‘02
ICIN
Intravascular Elastogram
of lesion pre-stenting
Strain [%]
1.0
0.0

14. CdK ‘02
ICIN
Intravascular Elastogram of stented lesion
Strain [%]
1.0
0.0

15. CdK ‘02
ICIN
• 6 Yucatan minipigs of 40 kg.
• Acquired elastographic data in left and right
femoral and external iliac artery (n=24).
• Cross-sections marked using angiography after
termination.
• Processed for histology: Elastic-von Giesson
Picro-Sirius red
Acid Phosphatase
Validation in atherosclerotic
Yucatan minipig

16. CdK ‘02
ICIN
Echogram and elastogram obtained in vivo in Yucatan
strain
1%
0%
Elastic-von Giesson Picro-Sirius red Acid Phosphatase
Polarized light
Circulation 105 (14): 1627-1630 (2002)

17. CdK ‘02
ICIN
Correlation elastography with histology
• Relation mean strain in total plaque with plaque
composition (fibrous, fatty, macrophages)
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 [%]
*
* P=0.007
Circulation 105 (14): 1627-1630 (2002)

18. CdK ‘02
ICIN
Correlation elastography with histology
• Presence of a high strain spot (>1% strain) with
presence of fat and or macrophages.
fat no fat
↑ ε 9 3
↓ ε 0 12
MΦ no MΦ
↑ ε 11 1
↓ ε 1 11
Circulation 105 (14): 1627-1630 (2002)

19. CdK ‘02
ICIN
3 Dimensional Elastography

20. CdK ‘02
ICIN
Conclusion
Intravascular Ultrasound Elastography:
A powerful technique to identify
the vulnerable plaque.