083 non invasive imaging of the vulnerable plaque
TRANSCRIPT
Non-Invasive Imaging of the Vulnerable Plaque and the
Vulnerable Patient
Non-invasive coronary angiography by CT and EBT
David G. King;Director, Clinical Sciences
GE Imatron
Acknowledgements:
John Rumberger:
“The tip of the iceberg” ….
20%20%
66%66%
33%33%
20%20%
Lipid RichLipid Rich
FibroticFibrotic
Fibrotic &Fibrotic &CalcifiedCalcified
The “Tip of theThe “Tip of theAtheroscleroticAtherosclerotic
IcebergIceberg””
Coronary Artery Plaque:Coronary Artery Plaque:approximate amounts of lipid rich, fibrotic and calcified plaqueapproximate amounts of lipid rich, fibrotic and calcified plaque
PlaquePlaqueDetectableDetectableby Intravascularby IntravascularUltrasound,Ultrasound,PathologyPathology
PlaquePlaqueDetectableDetectableby EBTby EBT
Acknowledgements:
John Rumberger:
“The tip of the iceberg” …..
“The Vulnerable Patient” ….. Jim Fixx,
1932-1984
Sir Winston Churchill
1874-1965
Non-calcified plaque components by EBT
Clinical significance unclear!
Points for discussion
Why non-invasive CTA?Who/what needs to be imaged?
What needs to be measured?
How can the patient outcome be changed as a result?
EBT 50 ms movie
Points for discussionCritical scanning parameters?
Scan speed
Triggering
Slice width
Image noise
Best use of dose delivered?
With or w/o contrast injection? EBT 50 ms movie
Points for discussionOptimum display of results:
Volume rendered?
Multiplanar reconstructions?
Maximum intensity projection?
Density distribution analysis?
EBT 50 ms movie
MSCT: LightSpeed – longer exposure, improved contrast resolutionSoft Plaque with Central Ulcer
Courtesy of Dr. Dowe, Atlantic Medical Imaging
Courtesy Dr. Sablayrolles Centre Cardiologique du Nord – Saint Denis
MSCT: SnapShot LightSpeed UltraStenosis in LAD 2nd Segment
Non-contrast EBT or EBA?
CAC study 50 ms EBA movie
Non-calcified ROI analysis
NormalNormal
CorAthCorAthCourtesy L.` Teichholz, MD
Density distribution in CAC studies
Density distribution• The mean voxel intensity (HU) within the ROI in
the proximal LAD is lower in patients with disease as compared to normals (p<0.005).
• The standard deviation of voxel intensities (HU) within the ROI in the proximal LAD is higher in patients with disease as compared to normals (p<0.00001).
• The percent of voxels with HU < 0 within the ROI in the proximal LAD is higher in patients with disease as compared to normals (p<0.00001).
Courtesy L. Teichholz, MD
Contrast-enhanced EBA
High speed & thin slices, yield improved spatial resolution
Venous branches, motion –diagnostic value?
The need for speed
300 msec 250 msec 200 msec 150 msec 100 msec 50 msec
Phantom “stenoses”
Requires coronary angiography?
250 msec 100 msec 50 msec
???
???
Conclusions• Benefits of high resolution
coronary vessel imaging:– Learn more about the
atherosclerotic disease process, hard & soft plaque
– Steer high risk subjects towards the appropriate intervention
– Reassure those with low probability of obstruction
– Keep the “normals” out of the cathlab