HYBRID INTRAVASCULAR
IMAGING
Hector M. Garcia-Garcia MD,
MSc, PhD, FESC, FACC
Director, Angio and IVUS/NIRS corelab
Chairman, Clinical Event Committee
Confidential 2016
• No disclosures
Outline
• IVUS and OCT combined catheters
• Scanning fiber endoscope
Hybrid Imaging –IVUS/OCT
1. OCT
1. PROS: Excellent resolution (10-20um)
enables more accurate visualization and
reconstruction of luminal , strut and plaque
morphology.
2. CONS: Limited penetration…
1. IVUS
1. PROS: Excellent penetration depth through
blood and soft tissue, enabling estimation of
vessel dimension, remodeling and plaque
burden
2. CONS: Limited soft tissue contrast and
resolution (>100um)
Hybrid Imaging –IVUS/OCT
The gray lines
OCT signal
through the optic
fiber, blue lines
signify electrical
signals and red
lines signify the
trigger signals
through electric
wires.
Schematic of IVUS-OCT imaging system and signal transmission system. (b) OCT and IVUS
images obtained (c) The imaging catheter . Li.J, Ma.T et al
COMBINED IVUS-OCT CATHETERS
Probe
Size
Probe
Arrangement
Probe
Characteristics
Image depth
Image
Axial
resolution
Frame Rate
Technical
Limitations
Histological
evidence
7.2Fr
First
reported
Side by Side
IVUS: 40 MHz
OCT: 1310nm
NA
IVUS: 38um
OCT: 8um
1/s
Large catheter size
Poor image
In vitro feasibility
study in rabbit
aorta
4Fr
(1m long
hybrid
catheter)
Side by side 90°
apart
IVUS: 42.5 MHz
OCT: 1325nm
OCT: 1mm
within tissue
NA
5/s
Increased
artefacts/moderate
image quality
Low frame rate
Poor co-registration in
the case of NURD
Qualitative
validation in
human cadavers
First coplanar
hybrid IVUS-OCT
catheter to image
human coronary
atherosclerosis.
3.6Fr
Sequential
arrangement
-2mm apart.
IVUS: 35 MHz
OCT: NA
IVUS: 4.5mm
OCT: NA
IVUS: 60um
OCT: 8um
20/s
Large catheter size
Inaccurate registration
of IVUS and OCT
Feasibility study
in human cadaver
and in vivo in the
aorta of the
rabbit
NA
NA
10/s
Low image acquisition
rate
Feasibility study
in human and
swine cadavers
NA
NA
100/s
None
Feasibilty in preclinical in-vivo
models
Plus fluorescence
imaging for plaque
characterization
2.7Fr
Back to back
IVUS: 45MHz
OCT: NA
Built to minimize
loss of coregistration caused
by cardiac motion
during pullback
3Fr
Co-linear ultrasound
and optical beams
Optics reside within
the ultrasound
transducer to
IVUS: 40 MHz
OCT: 1320nm
COMBINED IVUS-OCT CATHETERS
Catheterization and Cardiovascular Interventions 81:494–507 (2013)
COMBINED IVUS-OCT CATHETERS
The hybrid IVUS-OCT catheter has the potential to harness the
complementary advantages of both modalities and significantly improve the
ability to better characterize plaques.
Outline
• IVUS and OCT combined catheters
• Scanning fiber endoscope
Scanning fiber endoscope
excites tissues by blue, green and red lasers
Savastano L.E., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Garcia-Garcia H.M., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Scanning fiber endoscope
excites tissues by blue, green and red lasers
Backscattered (reflectance) light and fluorescent signal is collected by a
ring of optical fibers located in the periphery of the scanner housing and
shaft
Savastano L.E., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Garcia-Garcia H.M., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Scanning fiber endoscope
excites tissues by blue, green and red lasers
Savastano et al. demonstrated the first use of a novel multimodal endoscope
technology to collect laser-induced reflectance and fluorescence simultaneously and
perform structural and biological evaluation of atherosclerosis.
Savastano L.E., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Garcia-Garcia H.M., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
Scanning fiber endoscope
excites tissues by blue, green and red lasers
Ulcerated Plaque: Punched-out lesion with irregular elevated borders at the carotid
bifurcation on white-light system (k), red reflectance (l), and reflectance with green
(m) and blue (n) channels. Note the speckled pattern in the crater of the ulcer with
multiple irregular dots of strong autofluorescence in a background of very low
autofluorescence [>75 points of difference in color-coded bar chart of pixel values
of a line traced in (o), better appreciated in pseudocolor images (q)]. Histological
Savastano L.E., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
analysis of axial cut at the bifurcation reveals an atherosclerotic plaque [Movat’s
Garcia-Garcia H.M., et al. Nature Biomedical Engineering 1, Article number: 0023 (2017)
stain, (r)] with necrotic debris, some of which appears calcified, and fibrin (s), with
Multimodal laser-based angioscopy:
Conclusions
1. First intra-arterial forward-viewing device
capabe of generate real time structural,
chemical and biological images of the vascular
surface.
2. Feasibility for in vivo endovascular endoscopy
in an animal model with medium-sized
arteries.
3. Potential to become a new platorm for
research, diagnosis, prognosis and perhaps
image-guided local therapy in cardiovascular
disease.