<s>
In	O
the	O
fields	O
of	O
cardiology	O
and	O
medical	B-Application
imaging	I-Application
,	O
speckle	B-Algorithm
tracking	I-Algorithm
echocardiography	I-Algorithm
(	O
STE	O
)	O
is	O
an	O
echocardiographic	B-Application
imaging	I-Application
technique	O
.	O
</s>
<s>
It	O
analyzes	O
the	O
motion	O
of	O
tissues	O
in	O
the	O
heart	O
by	O
using	O
the	O
naturally	O
occurring	O
speckle	O
pattern	O
in	O
the	O
myocardium	O
(	O
or	O
motion	O
of	O
blood	O
when	O
imaged	O
by	O
ultrasound	B-Application
)	O
.	O
</s>
<s>
There	O
are	O
different	O
search	O
algorithms	O
,	O
the	O
most	O
commonly	O
used	O
is	O
"	O
sum	B-Algorithm
of	I-Algorithm
absolute	I-Algorithm
differences	I-Algorithm
"	O
,	O
shown	O
to	O
be	O
similarly	O
accurate	O
as	O
cross-correlation	O
,	O
which	O
is	O
an	O
alternative	O
.	O
</s>
<s>
However	O
,	O
as	O
the	O
axial	O
(	O
in	O
the	O
direction	O
of	O
the	O
beam	O
)	O
resolution	O
of	O
the	O
ultrasound	B-Application
is	O
far	O
better	O
than	O
the	O
transverse	O
,	O
the	O
tracking	O
ability	O
is	O
less	O
in	O
the	O
transverse	O
direction	O
.	O
</s>
<s>
Also	O
,	O
the	O
transverse	O
resolution	O
(	O
and	O
hence	O
,	O
tracking	O
ability	O
)	O
decreases	O
with	O
depth	O
,	O
in	O
a	O
sector	O
scan	O
were	O
ultrasound	B-Application
beams	O
diverge	O
.	O
</s>
<s>
Similar	O
to	O
MRI	B-Algorithm
,	O
STE	O
utilizes	O
"	O
Lagrangian	O
strain	O
"	O
which	O
defines	O
motion	O
around	O
a	O
particular	O
point	O
in	O
tissue	O
as	O
it	O
revolves	O
through	O
time	O
and	O
space	O
.	O
</s>
<s>
Strain	O
results	O
derived	O
from	O
STE	O
have	O
been	O
validated	O
using	O
sonomicrometry	O
and	O
tagged	O
MRI	B-Algorithm
and	O
results	O
correlate	O
significantly	O
with	O
Tissue	O
Doppler	O
–	O
derived	O
measurements	O
.	O
</s>
<s>
Tissue	O
Doppler	O
technology	O
,	O
the	O
alternative	O
method	O
for	O
strain	O
rate	O
imaging	O
to	O
speckle	O
tracking	O
technology	O
,	O
requires	O
achieving	O
sufficient	O
parallel	O
orientation	O
between	O
the	O
direction	O
of	O
motion	O
and	O
the	O
ultrasound	B-Application
beam	O
.	O
</s>
<s>
In	O
order	O
to	O
achieve	O
sufficient	O
tracking	O
quality	O
when	O
single	O
markers	O
are	O
used	O
,	O
however	O
commercial	O
algorithms	O
very	O
often	O
resort	O
to	O
varieties	O
of	O
spline	B-Algorithm
smoothing	I-Algorithm
using	O
available	O
information	O
from	O
the	O
strongest	O
echoes	O
,	O
very	O
oft	O
the	O
mitral	O
annulus	O
,	O
so	O
the	O
regional	O
measurements	O
are	O
not	O
pure	O
regional	O
,	O
but	O
rather	O
to	O
a	O
degree	O
,	O
spline	O
functions	O
of	O
the	O
global	O
average	O
.	O
</s>
<s>
In	O
the	O
study	O
by	O
Cho	O
et	O
al	O
,	O
both	O
TVI	O
derived	O
and	O
speckle	O
tracking	O
derived	O
longitudinal	O
strain	O
showed	O
modest	O
correlation	O
with	O
MRI	B-Algorithm
derived	O
strain	O
.	O
</s>
<s>
The	O
ROC	B-Algorithm
analysis	I-Algorithm
showed	O
significantly	O
higher	O
AUC	O
for	O
speckle	O
tracking	O
for	O
detecting	O
dysfunctional	O
segments	O
.	O
</s>
<s>
Each	O
vendor	O
of	O
ultrasound	B-Application
equipment	O
,	O
or	O
analysis	O
software	O
,	O
has	O
different	O
algorithms	O
,	O
that	O
will	O
perform	O
differently	O
during	O
analysis	O
.	O
</s>
