dynamic holographic imaging of the beating heart. how far to go ? patrick hunziker, md icu /...
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Dynamic holographic imaging of the beating heart.
How far to go ?
Patrick Hunziker, MDICU / Cardiology / Physics in Medicine Research Group
Basel University Hospital, Switzerland
Massachusetts General Hospital, Boston USA
Massachusetts Institute of Technology, Cambridge USA
Höhlen
Display of Multidimensional Echo Data
M-modeStatic 2D
dynamic 2Dsurface-rendered 3D
true 3D/4D+/- color
# ofdimensions 2 3 4
Info content:
Reporting:
0.2 MB
page
2 MB
videotapesdigital loops? print
20-100 MB
?
History of Echo Display
Dimension Display type
time strip 1954space X 1960’s
space Y
2D still image
1970’s2D movie
1980’sflow field 2D color movie
2000’sspace Z hologram
What is holography ?
interference patternobject beam
reference beam
holography = recording of data by light diffraction/interference
photosensitive substrate
fix pattern in substrate
reference beam
reconstructed object
types of holography:optical vs computational
real object
Laser
referencebeam
objectbeam
interferencepattern
light sensitive substrate
‘virtual object’
computation of virtual interference pattern
HOE
light sensitive substrate
Laser
LCD
illumination of real object with light necessary
virtual representation of object is enough
types of holography
holographic storageinterferometry
types of holography
display holography holographic video
conventional display holography: static representation of 3D objects
multiple perspective views
conventional hologram: static 3D shape
prior uses of holography in medicine
Display holographyCreate static 3D representation from X-rays
(Redman, Nature 1968)
holographic interferometry: nondestructive surface testingof heart valve prostheses (Zarubin, J Heart Valve Dis 1993)
conventional holography in cardiology
Vannan et al. J Am Soc Echocardiogr. 1995;8:567–575
Excised bovine heart
use ultrasound to create static, volumetric multiplexed display hologram
In echo, motion is key information
Goal:
to explore the ability of holography to display heart motion
by integration of space and time dimensions into digital print holograms
Display of motion by dynamic holography
static 3D imagechange of viewing angle
change of perspective
Conventional Holography
moving objectchange of viewing angle
change of timepoint
Dynamic Holography
Static versus dynamic holography
Conventional, static 3D hologram
conventional hologramscontains multiple
perspective views
Dynamic heart motion hologram
dynamic heart motionholograms containsmultiple timeframes
Methods
Echocardiogram HP Sonos 2500
data acquisition
optical disk
reformattingPCHP software
MEDIS
filter,crop,contrastNIH image software
postprocessingOne-stepdigital hologramprinting
UNIX
Viewing of dynamic heart holograms
dynamic (2d + time) hologram from standard echo images
1[1].mov
Hunziker, Circulation 1999
Results
- hologram printing pipeline- real-time preprocessing- printing time 10 min on prototype holographic printer ( technology similar to DVD reader/writer )
- plastic sheet of 0.3mm thickness- size 7x10cm- resolution >>> current echo machines- 640 x 480 pixels x 25 timeframes
Dynamic holographic images preserves quantitation
Hunziker, Circulation 1999
normal MV
dynamic (2D+time) holograms: comparative views
HOCM
MV prolapse myxoma
Quad.mov
dynamic surface-rendered (3D + time ) hologram
3d.mov
Advantages of dynamic heart holograms
display & reporting of echocardiograms:-a single page:
anatomy, contractile function, valvular function & Doppler
-no need for viewing stations
simple archiving scheme:-a single page
contains complete original image info
SummaryHolographic representation of heart motion
-is feasible -allows printing & display of the complete
heart cycle on a two-dimensional medium-can convey 3D anatomy + motion + flow
in a single printout
This novel technique has the potential to improve visualisation , reporting and archiving of echocardiographic imaging.
parallax in holography -> representation of 4 kinds of image information
horizontal parallax
vertical parallax
Smith, MIT Media Lab
Work in progress:
Exploitation of independence of horizontal and vertical parallax in digital holograms
=> combination of
true (volumetric) 3D + motion
work in progress II3 laser wavelengths
for RGB recording
full color
holograms
-> 3D + time + flow
in a simple printout !
Hunziker et al
Smith SL, MIT Media Lab
Outlook: holographic video
State of the art:
- a few prototypes worldwide
- still low resolution
- 15 fps
- monochrome
- need for huge bandwidths
-> display of moving 3D echo in the future ?
Will display holography ever play a role in echocardiography ?
Pro:
-currently, working with 3D echo is tedious ->
no widespread application outside the research lab.
-inherent problems of 3D display on a 2D screen
-hologram printer technology ~ level of DVD ROM
-capability of upcoming holographic video systems
Contra:
availability of hologram printers
will the future society be “all digital and all virtual” ?
Thanks to
My teachers in echocardiographyOsmund Bertel, Zurich
Dieter Burckhardt, Basel
Peter Buser, Basel
Mike Picard, Boston
Bob Levine, Boston
Arthur E Weyman, Boston
My family for support
The Swiss National Research Foundation