1. Dynamic holographic imaging of the beating heart. How far to go ?
Patrick Hunziker, MD
ICU / Cardiology / Physics in Medicine Research Group
Basel University Hospital, Switzerland
Massachusetts General Hospital, Boston USA
Massachusetts Institute of Technology, Cambridge USA

2. Höhlen

3. Display of Multidimensional Echo Data
dimensions 2 3 4
M-mode
Static 2D
dynamic 2D
surface-rendered 3D
true 3D/4D
+/- color
Info content:
0.2 MB
2 MB MB
Reporting:
page
videotapes
digital loops
? print ?

4. History of Echo Display
Dimension Display type
time strip
1954
1970’s
2D movie
2000’s
space Z hologram
1960’s
space Y
2D still image
space X
1980’s
flow field D color movie

5. What is holography ? l1 l2 l2 l1
holography = recording of data by light diffraction/interference l1 l2
interference pattern
object beam
reference beam
photosensitive substrate
fix pattern
in substrate l2
reference beam l1
reconstructed object

6. Kinds of holography optical holography digital holography Aim
static 3D image
change of viewing angle
change of perspective
Aim
To explore the ability of
holography
to display
cardiac motion
space X
space Y
space Z
Hologram
TIME
Conventional Holography
static 3D image
change of viewing angle
change of perspective
Dynamic Holography
moving object
change of viewing angle
change of timepoint
Kinds of holography
Production of Holograms:
Optical
Computational
technique:
technique:
Object
‘virtual
Laser
Laser
optical holography
object
digital holography
Laser
beam
object’
calculation of
hypothetical
reference
interference pattern
HOE
beam
LCD
interference
pattern
light sensitive
light sensitive
substrate
substrate
Methods
reformatting
MEDIS PC
optical disk
HP software
data acquisition
Echocardiogram
HP Sonos 2500
One-step
digital hologram
postprocessing
printing
filter,crop,contrast
NIH image
Conventional
Dynamic heart
hologram
motion hologram
conventional holograms
dynamic heart motion
contains multiple
holograms contains
perspective views
multiple timeframes
Viewing of dynamic
heart holograms
Characteristics of
dynamic heart holograms:
Resolution / Sharpness:
currently: 640*480 pixels*32 time-frames.
practically limited by computer power.
theoretically limited only by wavelength of laser.
no distortion
Color:
B/W & color images
Printing time :
Conventional methods: days to weeks.
Prototype ‘one-step laser-printers’: minutes.
additional applications of
dynamic heart holograms:
-2D echo + motion +
color Doppler -
rendered 3D
+ motion -
true 3D
+ motion -
true 3D +
color Doppler
+ motion
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
Holographic representation of heart motion
-is feasible
-allows printing & display of the complete
heart cycle on a two-dimensional medium.
This novel technique has the potential to
improve visualisation and
archiving of echocardiographic imaging.
Hunziker P, Circulation 1998, in print
Hypothesis:
Computational, dynamic holography
can be applied
to echo imaging of cardiac motion
in a variety of clinical states

7. types of holography: optical vs computational
real object
‘virtual object’
computation of
virtual
interference pattern
HOE
light sensitive substrate
Laser
LCD
Laser
reference
beam
object
interference
pattern
light sensitive substrate
illumination of real object
with light necessary
virtual representation of object
is enough

8. types of holography
interferometry
holographic storage

9. types of holography
display holography
holographic video

10. conventional display holography: static representation of 3D objects
multiple perspective views
conventional hologram: static 3D shape

11. prior uses of holography in medicine
Display holography
Create static 3D representation from X-rays
(Redman, Nature 1968)
holographic interferometry:
nondestructive surface testing
of heart valve prostheses (Zarubin, J Heart Valve Dis 1993)

12. conventional holography in cardiology
Excised bovine heart
use ultrasound to create static, volumetric multiplexed display hologram
Vannan et al.
J Am Soc Echocardiogr. 1995;8:567–575

13. 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

14. Display of motion by dynamic holography
static 3D image
change of viewing angle
change of perspective
Conventional Holography
moving object
change of viewing angle
change of timepoint
Dynamic Holography

15. Static versus dynamic holography
Conventional, static 3D hologram
conventional holograms
contains multiple
perspective views
Dynamic heart motion hologram
dynamic heart motion
holograms contains
multiple timeframes

16. Methods Echocardiogram HP Sonos 2500 data acquisition optical disk
reformatting PC
HP software
MEDIS
filter,crop,contrast
NIH image software
postprocessing
One-step
digital hologram
printing
UNIX

17. Viewing of dynamic heart holograms

18. dynamic (2d + time) hologram from standard echo images
Hunziker, Circulation 1999

19. 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

20. Dynamic holographic images preserves quantitation
Hunziker, Circulation 1999

21. dynamic (2D+time) holograms: comparative views
HOCM
normal MV
MV prolapse
myxoma

22. dynamic surface-rendered (3D + time ) hologram

23. 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

24. Summary Holographic 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.

25. parallax in holography -> representation of 4 kinds of image information
horizontal parallax
vertical
parallax
Smith, MIT Media Lab

26. Work in progress:
Exploitation of independence of horizontal and vertical parallax in digital holograms
=> combination of
true (volumetric) 3D + motion

27. work in progress II full color holograms 3 laser wavelengths
for RGB recording
full color
holograms
-> 3D + time + flow
in a simple printout !
Hunziker et al
Smith SL,
MIT Media Lab

28. 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 ?

29. 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” ?

30. Thanks to My teachers in echocardiography My family for support
Osmund 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