6. S

UM

MA

RY

& C

ON

CLU

SIO

NS

6. S

UM

MA

RY

& C

ON

CLU

SIO

NS

A c

orre

latio

n-ba

sed

optic

al fl

ow (O

F) m

etho

d w

as e

valu

ated

on

RT3

D

ultra

soun

d fo

r tra

ckin

g of

the

LV e

ndoc

ardi

al s

urfa

ce d

efin

ed a

tED

via

m

anua

l tra

cing

or s

egm

enta

tion

with

the

QLA

B©

softw

are

from

Phi

lips

Med

ical

Sys

tem

.

Qua

ntita

tive

eval

uatio

n sh

owed

pro

mis

ing

abili

ty o

f OF

track

ing

to fo

llow

th

e en

doca

rdia

l sur

face

on

open

-che

st a

nd c

linic

al d

ata

sets

.

Com

bine

d w

ith e

pica

rdiu

m tr

acki

ng a

nd ra

dial

bas

is fu

nctio

n in

terp

olat

ion,

den

se-fi

eld

myo

card

ial m

otio

n w

as re

cove

red,

and

an

alyz

ed fo

r dyn

amic

car

diac

info

rmat

ion.

This

stu

dy p

rovi

ded

enco

urag

ing

resu

lts re

gard

ing

OF

perfo

rman

ceto

ac

cura

tely

trac

k LV

sur

face

s, y

ield

dyn

amic

info

rmat

ion

from

RT3

D

ultra

soun

d, a

nd p

rovi

de a

utom

ated

dyn

amic

inte

rpol

atio

n of

seg

men

ted

endo

card

ial s

urfa

ces.

As

a se

mi-a

utom

ated

met

hod,

OF

base

d su

rface

trac

king

can

min

imiz

e te

diou

s hu

man

inte

rven

tion

for v

entri

cula

r mot

ion

anal

ysis

.

5. C

OM

PUTA

TIO

NA

L TI

ME

5. C

OM

PUTA

TIO

NA

L TI

ME

1 C

olum

bia

Uni

vers

ity, N

ew Y

ork,

NY

, U.S

.A.

2 E

cole

Nat

iona

le S

upér

ieur

e de

s Té

léco

mm

unic

atio

ns, D

épar

tem

ent T

raite

men

t du

Sig

nal e

t des

Imag

es (T

SI),

Par

is, F

ranc

e3 P

hilip

s Fr

ance

, Sur

esne

s, F

ranc

e

Trac

king

of L

V En

doca

rdia

l Sur

face

on

Rea

lTr

acki

ng o

f LV

Endo

card

ial S

urfa

ce o

n R

eal -- T

ime

Thre

eTi

me

Thre

e --D

imen

sion

al

Dim

ensi

onal

U

ltras

ound

with

Opt

ical

Flo

wU

ltras

ound

with

Opt

ical

Flo

w1 Q

i Dua

n, 2 E

lsa

Ang

elin

i, 1 S

usan

Her

z, 3 O

livie

r Ger

ard,

3 Pas

cal A

llain

, 1C

hris

toph

er In

gras

sia,

1 K

evin

Cos

ta,1

Jeffr

ey H

olm

es,1

Shun

ichi

Hom

ma,

1 And

rew

Lai

ne

1. IN

TRO

DU

CTI

ON

1. IN

TRO

DU

CTI

ON

Rea

l-tim

e th

ree-

dim

ensi

onal

(RT3

D) u

ltras

ound

with

mat

rix-p

hase

d ar

ray

trans

duce

rs [1

] ena

ble

fast

, non

-inva

sive

vis

ualiz

atio

n of

car

diac

ven

tricl

es.

Seg

men

tatio

n of

ven

tricu

lar v

olum

es o

n R

T3D

ultr

asou

nd is

typi

cally

per

form

ed a

t en

d-di

asto

le (E

D) a

nd e

nd-s

ysto

le (E

S).

Aut

omat

ion

of th

e se

gmen

tatio

n pr

oces

s an

d pr

opag

atio

n of

seg

men

tatio

n in

tim

e is

cha

lleng

ing.

In th

is c

onte

xt, a

cor

rela

tion-

base

d 3D

+Tim

e op

tical

flow

alg

orith

m w

as a

pplie

d fo

r tra

ckin

g of

myo

card

ial s

urfa

ces.

Initi

aliz

atio

n w

as p

erfo

rmed

with

eith

er m

anua

l tra

cing

or Q

LAB

©so

ftwar

e (P

hilip

s M

edic

al S

yste

ms)

.

4. D

YNA

MIC

CA

RD

IAC

INFO

RM

ATI

ON

4. D

YNA

MIC

CA

RD

IAC

INFO

RM

ATI

ON

4.1

Epic

ardi

um T

rack

ing

Res

ult

Epi

card

ium

Epi

card

ium

OF

track

ing

initi

aliz

ed w

ith

man

ual t

raci

ng w

as te

sted

on

the

clin

ical

dat

a.

Err

or m

easu

rem

ents

wer

e m

uch

low

er

than

for t

he e

ndoc

ardi

al s

urfa

ce.

At E

S, a

Ham

mer

map

err

or a

naly

sis

show

ed th

at 9

7% o

f the

epi

card

ial

surfa

ce tr

acke

d w

ith O

F re

sulte

d in

le

ss th

an 1

0% d

iffer

ence

s fro

m th

e m

anua

lly tr

aced

sur

face

.2.

MET

HO

DO

LOG

Y2.

MET

HO

DO

LOG

Y2.

1 C

orre

latio

n-B

ased

Opt

ical

Flo

w

A re

gion

-bas

ed o

ptic

al fl

ow m

etho

d us

ing

corr

elat

ion

mea

sure

s [2

] w

as a

pplie

d to

RT3

D u

ltras

ound

dat

a. C

orre

latio

n m

easu

res

are

robu

st to

noi

sy c

ondi

tions

and

can

ada

pt to

fast

mot

ion.

A d

ispl

acem

ent v

ecto

r for

two

cons

ecut

ive

time

fram

es w

as

com

pute

d vi

a m

axim

izat

ion

of th

e cr

oss-

corr

elat

ion

coef

ficie

nt:

Two

thre

shol

d pa

ram

eter

s w

ere

intro

duce

d:

A v

aria

nce

thre

shol

d to

lim

it th

e “a

pertu

re p

robl

em”.

An

aver

age

thre

shol

d to

lim

it th

e tra

ckin

g to

the

myo

card

ium

(“

brig

ht”r

egio

ns).

Reg

ular

izat

ion

of th

e di

spla

cem

ent f

ield

was

per

form

ed v

ia lo

cal

aver

agin

g on

a 6

-con

nect

ed n

eigh

borh

ood.

2.2

Rea

l-Tim

e Th

ree-

Dim

ensi

onal

Ultr

asou

nd D

ata

Sets

Trac

king

of t

he m

yoca

rdia

l sur

face

s w

as te

sted

on

3 da

ta s

ets

acqu

ired

with

a S

ON

OS

750

0 3D

ultr

asou

nd m

achi

ne (P

hilip

s M

edic

al S

yste

ms,

Bes

t, Th

e N

ethe

rland

s):

Two

data

set

s on

an

anes

thet

ized

ope

n ch

est d

ogbe

fore

(b

asel

ine)

and

2 m

inut

es a

fter i

nduc

tion

of is

chem

ia v

ia o

cclu

sion

of

the

prox

imal

left

ante

rior d

esce

ndin

g (L

AD

) cor

onar

y ar

tery

.O

ne tr

anst

hora

cic

clin

ical

dat

a se

t fro

m a

hea

rt-tr

ansp

lant

ed

patie

nt.

Dat

a ac

quis

ition

was

trig

gere

d w

ith E

KG

and

initi

aliz

ed a

t ED

.

Dat

a se

t siz

es: [

176

160

144]

with

16

fram

es fo

r 1 c

ardi

ac c

ycle

(dog

-ba

selin

e), [

176

160

144]

with

16

fram

es fo

r 1 c

ardi

ac c

ycle

(dog

-pos

t is

chem

ia),

[224

208

201

] with

16

fram

es fo

r 1 c

ardi

ac c

ycle

(pat

ient

).

()

22

(,)(

,)

(,)

(,

)

ItI

tt

rI

tI

tt

∈Ω ∈Ω∈Ω⋅+∆

+∆

=+∆

+∆

∑ ∑∑

x xx

xx

x

xx

x

Dog

Clin

ical

2.3

Segm

enta

tion

Man

ual T

raci

ng: A

n ex

pert

perfo

rmed

man

ual t

raci

ng o

f all

time

fram

es in

the

data

set

s, o

n ro

tatin

g B

-sca

n vi

ews

and

trans

latin

g

C

-sca

n vi

ews.

QLA

B©

Segm

enta

tion:

The

QLA

B©

softw

are

(Phi

lips

Med

ical

S

yste

ms)

was

use

d to

seg

men

t the

end

ocar

dial

sur

face

. Ini

tializ

atio

n w

as p

erfo

rmed

by

a hu

man

exp

ert a

nd a

par

amet

ric d

efor

mab

le

mod

el w

as fi

t to

the

data

at e

ach

time

fram

e. S

egm

ente

d su

rface

sw

ere

revi

ewed

by

expe

rt an

d m

anua

lly a

djus

ted

for f

inal

cor

rect

ion.

2. M

ETH

OD

OLO

GY

(con

t.)2.

MET

HO

DO

LOG

Y (c

ont.)

2.4

Surf

ace

Trac

king

with

Opt

ical

Flo

w

All

data

set

s w

ere

pre-

smoo

thed

with

ani

sotro

pic

diffu

sion

.

An

initi

al s

et o

f end

ocar

dial

sur

face

poi

nts

was

def

ined

(fro

m m

anua

l tra

cing

for d

og &

clin

ical

dat

a; a

lso

from

QLA

B©

for t

he c

linic

al d

ata)

.

Opt

ical

flow

(OF)

alg

orith

m w

as u

sed

to tr

ack

the

surfa

ce in

tim

e th

roug

h th

ew

hole

car

diac

cyc

le.

2.5

Qua

ntita

tive

Com

paris

on o

f Sur

face

s

Sur

face

reco

nstru

ctio

n is

bas

ed o

n fin

ite e

lem

ent m

odel

(FE

M) [

3].

Trac

ked

surfa

ces

wer

e re

gist

ered

with

ana

tom

ical

land

mar

ks a

nd

fitte

d in

to 6

4-el

emen

t mes

hes

in p

rola

te s

pher

oida

l coo

rdin

ates

(λ

,θ,φ

) with

bic

ubic

Her

mite

inte

rpol

atio

n [4

].

Qua

ntita

tive

mea

sure

men

ts:

Roo

t mea

n sq

uare

d er

rors

(RM

SE

) of t

he d

iffer

ence

of t

he ra

dial

co

ordi

nate

s λ

at n

ode

poin

ts fo

r OF

and

man

ual t

raci

ng s

urfa

ces.

Ven

tricu

lar v

olum

es.

Rel

ativ

e er

rors

wer

e us

ed to

gen

erat

e lo

cal r

elat

ive

erro

r map

s pl

otte

d as

Ham

mer

map

s.

0 0

0.1

0

00

-0.1

0

0 -0.1sept

uman

terio

rla

tera

lpo

ster

ior

sept

um

apex

-1.5

-1-0.5

00.5

4.2

Myo

card

ium

Mot

ion

Fiel

d an

d D

ynam

ic C

ardi

ac In

form

atio

n

Com

puta

tion

of a

dis

plac

emen

t vec

tor f

ield

bet

wee

n E

D a

nd E

S o

n th

e en

doca

rdia

l and

epi

card

ial s

urfa

ces

by

OF

track

ing.

Inte

rpol

atio

n of

myo

card

ial m

otio

n w

ith ra

dial

bas

is fu

nctio

ns.

Ext

ract

ion

of d

ynam

ic c

ardi

ac in

form

atio

n [5

]: ra

dial

dis

plac

emen

t, th

icke

ning

and

twis

t.M

otio

n Fi

eld

One

Slic

e

3D

Ren

derin

g

Rad

ial D

ispl

acem

ent

Thic

keni

ngTw

ist

AC

KN

OW

LED

GEM

ENTS

AC

KN

OW

LED

GEM

ENTS

This

wor

k w

as fu

nded

by

Nat

iona

l Sci

ence

Fou

ndat

ion

gran

t BE

S-0

2-01

617,

Am

eric

an H

eart

Ass

ocia

tion

#015

1250

T, P

hilip

s M

edic

al S

yste

ms,

New

Yo

rk S

tate

NYS

TAR

/CA

T Te

chno

logy

Pro

gram

, and

the

Loui

s M

orin

Fel

low

ship

pro

gram

. Dr.

And

rew

McC

ullo

ch a

t the

Uni

vers

ity o

f Cal

iforn

ia S

an D

iego

pr

ovid

ed th

e fin

ite e

lem

ent s

oftw

are

“Con

tinui

ty”t

hrou

gh th

e N

atio

nal B

iom

edic

al C

ompu

tatio

n R

esou

rce

(NIH

P41

RR

0860

5).

Th

e au

thor

s al

so w

ould

like

to th

ank

Todd

Pul

erw

itz, M

.D. (

Dep

artm

ent o

f Med

icin

e, C

olum

bia

Uni

vers

ity) f

or h

is e

fforts

in a

cqui

ring

the

ultra

soun

d da

ta s

ets.

1025

161

Opt

ical

Flo

w

160

160

7010

Hum

an E

xper

t

Hum

an

Invo

lvem

ent

(min

utes

)

Tota

l tim

efo

r ful

l cyc

le(m

inut

es)

Tota

l tim

efo

r eje

ctio

n ph

ase

(min

utes

)

Sin

gle

fram

e (m

inut

es)

Test

ing

Env

ironm

ent:

“C”c

ode

on a

2.4

GH

z A

MD

64-

bit s

erve

r, ru

nnin

g R

edha

tLin

ux

3. R

ESU

LTS

3. R

ESU

LTS

3.1

Ope

n-C

hest

Dog

Dat

a

-0.1

0.1

0.1

0.1

0

0.2

0.2

0.1

0

-0.2

0

0

0.2

-0.2

-0.2

0.1

sept

uman

terio

rla

tera

lpo

ster

ior

sept

um

apex

-1.5

-1-0.5

00.5

-2 -2

0.1

00

-0.5

-0.5

-0.2

0

0.2

0.1

-0.2-0.2

0.1

0.2

0.2

0.1

0

-0.5

0.2

sept

uman

terio

rla

tera

lpo

ster

ior

sept

um

apex

-1.5

-1-0.5

00.5

Lat.

Ant.

Lat.

Ant.

RM

SE

Max

. erro

r = Bas

elin

e: 0

.19

(fram

e 11

)Is

chem

ia:0

.08

(fram

e 12

)(λ

=0.7±

0.3

at E

D λ

=0.6±

0.2

at E

S)

Max

. erro

r= 5

ml

LV V

olum

e (p

ost i

sche

mia

)LV

Vol

ume

(bas

elin

e)

Max

err

or =

7ml

05

1015

020406080

Fram

e N

umbe

r

Volume (ml)

Man

ual

OF

05

1015

0

0.1

0.2

0.3

0.4

0.5

Fram

e N

umbe

r

RMSE

Bas

elin

eIs

chem

ia

05

1015

020406080

Fram

e N

umbe

r

Volume (ml)

Man

ual

OF

3.2

Clin

ical

Dat

a

Exp

erim

ents

: For

war

d an

d ba

ckw

ard

track

ing

and

re-in

itial

izat

ion

usin

g m

anua

l tra

cing

and

QLA

B©

segm

enta

tion.

02

46

0

0.1

0.2

0.3

0.4

0.5

Fram

e N

umbe

r

RMSE

Forw

ard

Bac

kwar

d

RM

SE

12

34

50

0.1

0.2

0.3

0.4

0.5

Fram

e N

umbe

r

RMSE

No

re-in

itial

izat

ion

Re-

initi

aliz

atio

n ev

ery

4 fra

mes

Re-

initi

aliz

atio

n ev

ery

othe

r fra

me

Com

bini

ng fo

rwar

d an

dba

ckw

ard

track

ing

RM

SE

Usi

ng M

anua

l tra

cing

Usi

ng Q

LAB

©

Max

. erro

r = Man

ual:

0.09

(fra

me

09)

QLA

B©

:0.0

8 (fr

ame

10)

(λ=0

.6±

0.3

at E

D λ

=0.5±

0.2

at E

S)M

ax. e

rror =

10m

l

05

1015

0

0.1

0.2

0.3

0.4

0.5

Fram

e N

umbe

r

RMSE

Man

ual

QLA

B

05

1015

020406080

Fram

e N

umbe

r

Volume (ml)

Man

ual

OF

0-0

.1

0.1

0

0

0.1

0.2

0.1 0.2

0

-0.2

-0.5

0.20.

1

sept

uman

terio

rla

tera

lpo

ster

ior

sept

um

apex

-1.5

-1-0.5

00.5

-1

0 0.1

0.1

0

0-0.5

-1

-0.2

-0.5

-0.2

0

0.1

0.2 -0

.2-0

.1

0

sept

uman

terio

rla

tera

lpo

ster

ior

sept

um

apex

-1.5

-1-0.5

00.5

λ di

ff.

Lat.

Ant.

Lat.

Ant.

RM

SE

&

Volu

me

Ham

mer

m

aps

RM

SE

&

Volu

me

Ham

mer

m

aps

05

1015

020406080

Fram

eN

umbe

r

Volume (ml)

RM

SE

&

Volu

me

λ di

ff.

OF

vs. m

anua

l tra

cing

O

F vs

. QLA

B©

segm

enta

tion

ESES

λ di

ff.λ

diff.

OF

vs. m

anua

l tra

cing

at

bas

elin

e O

F vs

. man

ual t

raci

ng

at p

ost i

sche

mia

ESES

Max

. erro

r=13

ml

QLA

BO

F

REF

EREN

CES

REF

EREN

CES

[1] O

. T. v

on R

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, et a

l, “R

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umet

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tem

s,”J

ourn

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f Dig

ital I

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vol.

3, p

p. 2

61-2

66, 1

990.

[2

] J. L

. Bar

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et a

l, “P

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rman

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f Opt

ical

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w T

echn

ique

s,”I

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of C

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ter V

isio

n, v

ol. 1

2, p

p.43

-77,

199

4.[3

] S. H

erz,

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[4] C

. M. I

ngra

ssia

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l, “Im

pact

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ion

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iona

l Wal

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f BM

ES

, 200

3.[5

] M. S

uhlin

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t al,

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ode

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EE

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-10

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