1) Growing evidence suggests that CT-based characterization of coronary plaques and arteries is possible and may serve as an initial screening tool for at-risk patients. 2) 16 slice MS-CT can reliably detect coronary obstructions over 50% if combined with heart rate control under 65 bpm and can identify soft, intermediate, and calcified plaques. 3) Combining CT imaging with serum markers may provide a more powerful predictive value for identifying vulnerable plaque.

1. Editorial Slides
VP Watch – December 18, 2002 - Volume 2, Issue 50
Is CT-Based Characterization Of CoronaryIs CT-Based Characterization Of Coronary
Plaque/Artery Possible?Plaque/Artery Possible?
Provided by:
P.J. de Feijter, M.D.
Department of Cardiology and Radiology, Erasmus University
Rotterdam, The Netherlands

2. MS-CT : Goal
Visualizing and characterizing the diseased coronary
arterial wall in living patients. To evaluate:
- progression / regression
- risk factor modification
- coronary plaque treatment
- vulnerability to rupture
- site and extent of coronary obstruction

3. Milestones in Coronary Plaque
Imaging with (MS)-CT
- First EBCT coronary angiography
Achenbach NEJM 1998;339:1964
Rensing Circulation 1998; 98:2509
- First 4 slice MS-CT coronary angiography
Nieman Lancet 2001; 357: 599
- First in vivo 4 slice MS-CT coronary plaque imaging
Schroeder S. et al JACC 2001;37:1430-5
- First 16 slice MS-CT coronary angiography
Nieman Circulation 2002; 106: 2051
- Preliminary results 16 slice MS-CT
coronary plaque imaging

4. Coronary Plaque Imaging :
the “extreme” challenge
- small caliber vessels
- small size of plaques
- continuous cardiac and respiratory motion
- calcification (obscures underlying structures)
- modest attenuation variation between lipid-rich
and fibrous tissue components

5. 16 Slice MS-CT Coronary
Angiography
Suspected CAD : 58 subjects (53 male; 58 ± 12 yrs)
Average heart rate : 56 ± 6 b.p.m. (with additional ß-blocker)
Detection of ≥ 50% stenosis in all coronary vessels > 2.0mm
No exclusion of vessels (or segments)
Sensitivity : 95% Pos.Pred.Value : 80%
Specificity : 86% Neg.Pred.Value : 97%
Nieman Circulation 2002;106:2051

6. MS-CT – coronary angiography

7. Diagnostic Accuracy MS-CT
coronary angiography
4 slice MS-CT
Achenbach
Circulation 2001
4 slice MS-CT
Nieman
Heart 2002
16 slice MS-CT
Nieman
Circulation 2002
Detection of >50% diameter obstruction without exclusion of
coronary vessels or segments due to suboptimal image quality
Sensitivity 55% 65% 95%

8. MS-CT : Plaque Characterization
- Morphology
* presence, location,
distribution
* plaque size
* vessel remodeling
- Plaque composition
* Lipid
* fibrous tissue
* calcium
- Inflammation
MS - CT
+
+
Soft ( 0 – 30 HU )
Hard ( 31 – 130 HU )
Calcific ( >130 HU )

9. Coronary Plaque Imaging
- Examples
Normal
Calcific spots Calcium & stenosis
Severe stenosis
Total occlusion

10. 70
300 150
500
600
300
200
30
MS-CT Coronary Plaque Imaging

11. 4slice MS-CT Coronary Plaque Evaluation
Comparison of ICUS with MS-CT
Plaques
(n)
12
5
17
ICUS
(echogenicity)
Soft
Intermediate
Calcified
MS-CT
(Hounsfield Units)
14 ± 26
91 ± 21
419 ± 194
Schroeder et al JACC 2001;37:1430

12. 280HU
280HU80HU
30HU
450HU
MS-CT Coronary Plaque Imaging

13. Work-Up High Risk Patients
Clinical presentation
< 60 yrs old Diabetes Acute coronary syndrome
Biochemical markers
Elevated C-PR
Non-invasive MS-CT
Localization of plaque Characterization of plaque
Invasive techniques
IVUS Palpography Thermography OCT

14.  As reported in this week’s VP
Watch, Teichholz et al. showed
quantitative assessment of
atherosclerosis by EBT.
Teichholz LE, Petrillo S, Larson AJ, Klig V. Quantitative assessment of atherosclerosis by electron beam tomography.
Am J Cardiol. 2002 Dec 15;90(12):1416-9.

15.  They showed 3 new EBT parameters for
a region of interest (ROI):
 Mean value of Hounsfield Units (HU) within
the ROI
 Standard deviation (SD) of HU within the
ROI
 Percent of voxels with HU < 0 within the ROI
Teichholz LE, Petrillo S, Larson AJ, Klig V. Quantitative assessment of atherosclerosis by electron beam tomography.
Am J Cardiol. 2002 Dec 15;90(12):1416-9.

16.  The mean voxel intensity (HU) within the ROI in
the proximal LAD was lower in patients with CAD
compared to normals subjects.
 The standard deviation of voxel intensities within
the ROI in the proximal LAD was higher in patients
with CAD as compared to normal subjects.
 The percent of voxels with HU < 0 within the ROI
in the proximal LAD was higher in patients with
CAD.
Teichholz LE, Petrillo S, Larson AJ, Klig V. Quantitative assessment of atherosclerosis by electron beam tomography.
Am J Cardiol. 2002 Dec 15;90(12):1416-9.

17. 0
5
10
15
20
25
30
35
40
Normal
CAD
(p<0.005)
HU
Mean Voxel Intensity (HU) in LAD
Teichholz LE, Petrillo S, Larson AJ, Klig V. Quantitative assessment of atherosclerosis by electron beam tomography.
Am J Cardiol. 2002 Dec 15;90(12):1416-9.

18. • 16 MS-CT Coronary Imaging:
– A reliable non-invasive technique to detect
coronary obstructions if combined with intensive
heart rate control to <65 b.p.m.
– Can be used for identification of soft, intermediate
and calcific plaques.
– Offers great potential as an initial non-invasive
technique to identify vulnerable plaque / artery in
at risk population
Conclusion:

19. Conclusion:
• Growing body of evidence suggest
that CT-based characterization of
coronary plaques and/or artery is
possible, and this technology may
serve as the first line imaging tool for
screening vulnerable patients.
• Combination of CT with serum
markers of vulnerability may provide a
much more powerful predictive value.

20. Department of Cardiology1
and
Radiology2
Erasmus University
Rotterdam, The Netherlands
P.J. de Feijter1, 2
K. Nieman1 2
N.R.A. Mollet1 2
R. Raaijmakers2
F. Cademartiri2
J. Ligthart1
P. Lemos1
P.Pattynama2
P.W. Serruys1
Most of the Editorial Slides of this week were provided
by Dr de Feijter and his colleagues: