Dynamic holographic imaging of the beating heart. How far to go ? Patrick Hunziker, MD ICU / Cardiology / Physics in Medicine Research Group Basel University.

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