<s>
Medical	B-Application
ultrasound	I-Application
includes	O
diagnostic	O
techniques	O
(	O
mainly	O
imaging	B-Application
techniques	O
)	O
using	O
ultrasound	B-Application
,	O
as	O
well	O
as	O
therapeutic	B-Algorithm
applications	O
of	O
ultrasound	B-Application
.	O
</s>
<s>
The	O
usage	O
of	O
ultrasound	B-Application
to	O
produce	O
visual	O
images	O
for	O
medicine	O
is	O
called	O
medical	B-Application
ultrasonography	I-Application
or	O
simply	O
sonography	B-Application
.	O
</s>
<s>
The	O
practice	O
of	O
examining	O
pregnant	O
women	O
using	O
ultrasound	B-Application
is	O
called	O
obstetric	O
ultrasonography	O
,	O
and	O
was	O
an	O
early	O
development	O
of	O
clinical	O
ultrasonography	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
composed	O
of	O
sound	O
waves	O
with	O
frequencies	O
greater	O
than	O
20,000	O
Hz	O
,	O
which	O
is	O
by	O
approximation	O
the	O
upper	O
threshold	O
of	O
human	O
hearing	O
.	O
</s>
<s>
Ultrasonic	O
images	O
,	O
also	O
known	O
as	O
sonograms	O
,	O
are	O
created	O
by	O
sending	O
pulses	O
of	O
ultrasound	B-Application
into	O
tissue	O
using	O
a	O
probe	O
.	O
</s>
<s>
The	O
ultrasound	B-Application
pulses	B-Protocol
echo	I-Protocol
off	O
tissues	O
with	O
different	O
reflection	O
properties	O
and	O
are	O
returned	O
to	O
the	O
probe	O
which	O
records	O
and	O
displays	O
them	O
as	O
an	O
image	O
.	O
</s>
<s>
A	O
general-purpose	O
ultrasound	B-Algorithm
transducer	I-Algorithm
may	O
be	O
used	O
for	O
most	O
imaging	B-Application
purposes	O
but	O
some	O
situations	O
may	O
require	O
the	O
use	O
of	O
a	O
specialized	O
transducer	B-Algorithm
.	O
</s>
<s>
Most	O
ultrasound	B-Application
examination	O
is	O
done	O
using	O
a	O
transducer	B-Algorithm
on	O
the	O
surface	O
of	O
the	O
body	O
,	O
but	O
improved	O
visualization	O
is	O
often	O
possible	O
if	O
a	O
transducer	B-Algorithm
can	O
be	O
placed	O
inside	O
the	O
body	O
.	O
</s>
<s>
For	O
this	O
purpose	O
,	O
special-use	O
transducers	B-Algorithm
,	O
including	O
transvaginal	B-Algorithm
,	O
endorectal	O
,	O
and	O
transesophageal	B-Algorithm
transducers	B-Algorithm
are	O
commonly	O
employed	O
.	O
</s>
<s>
At	O
the	O
extreme	O
,	O
very	O
small	O
transducers	B-Algorithm
can	O
be	O
mounted	O
on	O
small	O
diameter	O
catheters	O
and	O
placed	O
within	O
blood	O
vessels	O
to	O
image	O
the	O
walls	O
and	O
disease	O
of	O
those	O
vessels	O
.	O
</s>
<s>
The	O
imaging	B-Application
mode	O
refers	O
to	O
probe	O
and	O
machine	O
settings	O
that	O
result	O
in	O
specific	O
dimensions	O
of	O
the	O
ultrasound	B-Application
image	O
.	O
</s>
<s>
Several	O
modes	O
of	O
ultrasound	B-Application
are	O
used	O
in	O
medical	B-Application
imaging	I-Application
:	O
</s>
<s>
A-mode	O
:	O
Amplitude	O
mode	O
refers	O
to	O
the	O
mode	O
in	O
which	O
the	O
amplitude	O
of	O
the	O
transducer	B-Algorithm
voltage	O
is	O
recorded	O
as	O
a	O
function	O
of	O
two-way	O
travel	O
time	O
of	O
an	O
ultrasound	B-Application
pulse	O
.	O
</s>
<s>
A	O
single	O
pulse	O
is	O
transmitted	O
through	O
the	O
body	O
and	O
scatters	O
back	O
to	O
the	O
same	O
transducer	B-Algorithm
element	O
.	O
</s>
<s>
B-mode	O
:	O
In	O
brightness	O
mode	O
,	O
an	O
array	O
of	O
transducer	B-Algorithm
elements	O
scans	O
a	O
plane	O
through	O
the	O
body	O
resulting	O
in	O
a	O
two-dimensional	O
image	O
.	O
</s>
<s>
Each	O
pixel	B-Algorithm
value	O
of	O
the	O
image	O
correlates	O
to	O
voltage	O
amplitude	O
registered	O
from	O
backscattered	O
signal	O
.	O
</s>
<s>
The	O
backscattered	O
signal	O
is	O
converted	O
to	O
lines	O
of	O
bright	O
pixels	B-Algorithm
,	O
whose	O
brightness	O
linearly	O
correlates	O
to	O
backscattered	O
voltage	O
amplitudes	O
.	O
</s>
<s>
This	O
mode	O
is	O
an	O
ultrasound	B-Application
analogy	O
to	O
streak	O
video	O
recording	O
in	O
high-speed	O
photography	O
.	O
</s>
<s>
Most	O
machines	O
convert	O
two-way	O
time	O
to	O
imaging	B-Application
depth	O
using	O
as	O
assumed	O
speed	O
of	O
sound	O
of	O
1540	O
m/s	O
.	O
</s>
<s>
As	O
the	O
actual	O
speed	O
of	O
sound	O
varies	O
greatly	O
in	O
different	O
tissue	O
types	O
,	O
an	O
ultrasound	B-Application
image	O
is	O
therefore	O
not	O
a	O
true	O
tomographic	O
representation	O
of	O
the	O
body	O
.	O
</s>
<s>
Three-dimensional	O
imaging	B-Application
is	O
done	O
by	O
combining	O
B-mode	O
images	O
,	O
using	O
dedicated	O
rotating	O
or	O
stationary	O
probes	O
.	O
</s>
<s>
An	O
imaging	B-Application
technique	O
refers	O
to	O
a	O
method	O
of	O
signal	O
generation	O
and	O
processing	O
that	O
results	O
in	O
a	O
specific	O
application	O
.	O
</s>
<s>
Most	O
imaging	B-Application
techniques	O
are	O
operating	O
in	O
B-mode	O
.	O
</s>
<s>
Doppler	B-Algorithm
sonography	I-Algorithm
:	O
This	O
imaging	B-Application
technique	O
makes	O
use	O
of	O
the	O
Doppler	O
effect	O
in	O
detection	O
and	O
measuring	O
moving	O
targets	O
,	O
typically	O
blood	O
.	O
</s>
<s>
Harmonic	O
imaging	B-Application
:	O
backscattered	O
signal	O
from	O
tissue	O
is	O
filtered	O
to	O
comprise	O
only	O
frequency	O
content	O
of	O
at	O
least	O
twice	O
the	O
centre	O
frequency	O
of	O
the	O
transmitted	O
ultrasound	B-Application
.	O
</s>
<s>
Harmonic	O
imaging	B-Application
used	O
for	O
perfusion	O
detection	O
when	O
using	O
ultrasound	B-Application
contrast	B-Algorithm
agents	I-Algorithm
and	O
for	O
the	O
detection	O
of	O
tissue	O
harmonics	O
.	O
</s>
<s>
B-flow	O
is	O
an	O
imaging	B-Application
technique	O
that	O
digitally	O
highlights	O
moving	O
reflectors	O
(	O
mainly	O
red	O
blood	O
cells	O
)	O
while	O
suppressing	O
the	O
signals	O
from	O
the	O
surrounding	O
stationary	O
tissue	O
.	O
</s>
<s>
It	O
is	O
thus	O
an	O
alternative	O
or	O
complement	O
to	O
Doppler	B-Algorithm
ultrasonography	I-Algorithm
in	O
visualizing	O
blood	O
flow	O
.	O
</s>
<s>
Therapeutic	B-Algorithm
ultrasound	I-Algorithm
aimed	O
at	O
a	O
specific	O
tumor	O
or	O
calculus	O
is	O
not	O
an	O
imaging	B-Application
mode	O
.	O
</s>
<s>
Compared	O
to	O
other	O
medical	B-Application
imaging	I-Application
modalities	O
,	O
ultrasound	B-Application
has	O
several	O
advantages	O
.	O
</s>
<s>
It	O
provides	O
images	O
in	O
real-time	O
,	O
is	O
portable	B-Algorithm
,	O
and	O
can	O
consequently	O
be	O
brought	O
to	O
the	O
bedside	O
.	O
</s>
<s>
It	O
is	O
substantially	O
lower	O
in	O
cost	O
than	O
other	O
imaging	B-Application
strategies	O
.	O
</s>
<s>
Drawbacks	O
include	O
various	O
limits	O
on	O
its	O
field	O
of	O
view	O
,	O
the	O
need	O
for	O
patient	O
cooperation	O
,	O
dependence	O
on	O
patient	O
physique	O
,	O
difficulty	O
imaging	B-Application
structures	O
obscured	O
by	O
bone	O
,	O
air	O
or	O
gases	O
,	O
and	O
the	O
necessity	O
of	O
a	O
skilled	O
operator	O
,	O
usually	O
with	O
professional	O
training	O
.	O
</s>
<s>
Sonography	B-Application
(	O
ultrasonography	O
)	O
is	O
widely	O
used	O
in	O
medicine	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
perform	O
both	O
diagnosis	O
and	O
therapeutic	B-Algorithm
procedures	I-Algorithm
,	O
using	O
ultrasound	B-Application
to	O
guide	O
interventional	O
procedures	O
such	O
as	O
biopsies	O
or	O
to	O
drain	O
collections	O
of	O
fluid	O
,	O
which	O
can	O
be	O
both	O
diagnostic	O
and	O
therapeutic	B-Algorithm
.	O
</s>
<s>
Sonographers	O
are	O
medical	O
professionals	O
who	O
perform	O
scans	O
which	O
are	O
traditionally	O
interpreted	O
by	O
radiologists	O
,	O
physicians	O
who	O
specialize	O
in	O
the	O
application	O
and	O
interpretation	O
of	O
medical	B-Application
imaging	I-Application
modalities	O
,	O
or	O
by	O
cardiologists	O
in	O
the	O
case	O
of	O
cardiac	O
ultrasonography	O
(	O
echocardiography	B-Application
)	O
.	O
</s>
<s>
Sonography	B-Application
is	O
effective	O
for	O
imaging	B-Application
soft	O
tissues	O
of	O
the	O
body	O
.	O
</s>
<s>
In	O
anesthesiology	O
,	O
ultrasound	B-Application
is	O
commonly	O
used	O
to	O
guide	O
the	O
placement	O
of	O
needles	O
when	O
injecting	O
local	O
anesthetic	O
solutions	O
in	O
the	O
proximity	O
of	O
nerves	O
identified	O
within	O
the	O
ultrasound	B-Application
image	O
(	O
nerve	O
block	O
)	O
.	O
</s>
<s>
In	O
angiology	O
or	O
vascular	O
medicine	O
,	O
duplex	B-Algorithm
ultrasound	I-Algorithm
(	O
B	O
Mode	O
imaging	B-Application
combined	O
with	O
Doppler	O
flow	O
measurement	O
)	O
is	O
used	O
to	O
diagnose	O
arterial	O
and	O
venous	O
disease	O
.	O
</s>
<s>
This	O
is	O
particularly	O
important	O
in	O
potential	O
neurologic	O
problems	O
,	O
where	O
carotid	B-Algorithm
ultrasound	I-Algorithm
is	O
commonly	O
used	O
for	O
assessing	O
blood	O
flow	O
and	O
potential	O
or	O
suspected	O
stenosis	O
in	O
the	O
carotid	O
arteries	O
,	O
while	O
transcranial	O
Doppler	O
is	O
used	O
for	O
imaging	B-Application
flow	O
in	O
the	O
intracerebral	O
arteries	O
.	O
</s>
<s>
Intravascular	O
ultrasound	B-Application
(	O
IVUS	O
)	O
uses	O
a	O
specially	O
designed	O
catheter	O
with	O
a	O
miniaturized	O
ultrasound	B-Algorithm
probe	I-Algorithm
attached	O
to	O
its	O
distal	O
end	O
,	O
which	O
is	O
then	O
threaded	O
inside	O
a	O
blood	O
vessel	O
.	O
</s>
<s>
The	O
proximal	O
end	O
of	O
the	O
catheter	O
is	O
attached	O
to	O
computerized	O
ultrasound	B-Application
equipment	O
and	O
allows	O
the	O
application	O
of	O
ultrasound	B-Application
technology	O
,	O
such	O
as	O
a	O
piezoelectric	O
transducer	B-Algorithm
or	O
capacitive	B-Algorithm
micromachined	I-Algorithm
ultrasonic	I-Algorithm
transducer	I-Algorithm
,	O
to	O
visualize	O
the	O
endothelium	O
of	O
blood	O
vessels	O
in	O
living	O
individuals	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
the	O
common	O
and	O
potentially	O
,	O
serious	O
problem	O
of	O
blood	O
clots	O
in	O
the	O
deep	O
veins	O
of	O
the	O
leg	O
,	O
ultrasound	B-Application
plays	O
a	O
key	O
diagnostic	O
role	O
,	O
while	O
ultrasonography	B-Application
of	I-Application
chronic	I-Application
venous	I-Application
insufficiency	I-Application
of	I-Application
the	I-Application
legs	I-Application
focuses	O
on	O
more	O
superficial	O
veins	O
to	O
assist	O
with	O
planning	O
of	O
suitable	O
interventions	O
to	O
relieve	O
symptoms	O
or	O
improve	O
cosmetics	O
.	O
</s>
<s>
Echocardiography	B-Application
is	O
an	O
essential	O
tool	O
in	O
cardiology	O
,	O
assisting	O
in	O
evaluation	O
of	O
heart	O
valve	O
function	O
,	O
such	O
as	O
stenosis	O
or	O
insufficiency	O
,	O
strength	O
of	O
cardiac	O
muscle	O
contraction	O
,	O
and	O
hypertrophy	O
or	O
dilatation	O
of	O
the	O
main	O
chambers	O
.	O
</s>
<s>
Point	B-Algorithm
of	I-Algorithm
care	I-Algorithm
ultrasound	I-Algorithm
has	O
many	O
applications	O
in	O
emergency	O
medicine	O
.	O
</s>
<s>
These	O
include	O
differentiating	O
cardiac	O
from	O
pulmonary	O
causes	O
of	O
acute	O
breathlessness	O
,	O
and	O
the	O
Focused	O
Assessment	O
with	O
Sonography	B-Application
for	O
Trauma	O
(	O
FAST	O
)	O
exam	O
,	O
extended	O
to	O
include	O
assessment	O
for	O
significant	O
hemoperitoneum	O
or	O
pericardial	O
tamponade	O
after	O
trauma	O
(	O
EFAST	O
)	O
.	O
</s>
<s>
Other	O
uses	O
include	O
assisting	O
with	O
differentiating	O
causes	O
of	O
abdominal	B-Algorithm
pain	O
such	O
as	O
gallstones	O
and	O
kidney	O
stones	O
.	O
</s>
<s>
Emergency	O
Medicine	O
Residency	O
Programs	O
have	O
a	O
substantial	O
history	O
of	O
promoting	O
the	O
use	O
of	O
bedside	O
ultrasound	B-Application
during	O
physician	O
training	O
.	O
</s>
<s>
Both	O
abdominal	B-Algorithm
and	O
endoanal	B-Algorithm
ultrasound	I-Algorithm
are	O
frequently	O
used	O
in	O
gastroenterology	O
and	O
colorectal	O
surgery	O
.	O
</s>
<s>
In	O
abdominal	B-Algorithm
sonography	B-Application
,	O
the	O
major	O
organs	O
of	O
the	O
abdomen	O
such	O
as	O
the	O
pancreas	O
,	O
aorta	O
,	O
inferior	O
vena	O
cava	O
,	O
liver	O
,	O
gall	O
bladder	O
,	O
bile	O
ducts	O
,	O
kidneys	O
,	O
and	O
spleen	O
may	O
be	O
imaged	O
.	O
</s>
<s>
:	O
appendicitis	O
)	O
and	O
ultrasound	B-Application
is	O
the	O
initial	O
imaging	B-Application
choice	O
,	O
avoiding	O
radiation	O
if	O
possible	O
,	O
although	O
it	O
frequently	O
needs	O
to	O
be	O
followed	O
by	O
other	O
imaging	B-Application
methods	O
such	O
as	O
CT	O
.	O
Endoanal	B-Algorithm
ultrasound	I-Algorithm
is	O
used	O
particularly	O
in	O
the	O
investigation	O
of	O
anorectal	O
symptoms	O
such	O
as	O
fecal	O
incontinence	O
or	O
obstructed	O
defecation	O
.	O
</s>
<s>
It	O
uses	O
transducers	B-Algorithm
designed	O
for	O
approaches	O
through	O
the	O
lower	O
abdominal	B-Algorithm
wall	O
,	O
curvilinear	O
and	O
sector	O
,	O
and	O
specialty	O
transducers	B-Algorithm
such	O
as	O
Transvaginal	B-Algorithm
ultrasound	I-Algorithm
.	O
</s>
<s>
Obstetrical	O
sonography	B-Application
was	O
originally	O
developed	O
in	O
the	O
late	O
1950s	O
and	O
1960s	O
by	O
Sir	O
Ian	O
Donald	O
and	O
is	O
commonly	O
used	O
during	O
pregnancy	O
to	O
check	O
the	O
development	O
and	O
presentation	O
of	O
the	O
fetus	O
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
identify	O
many	O
conditions	O
that	O
could	O
be	O
potentially	O
harmful	O
to	O
the	O
mother	O
and/or	O
baby	O
possibly	O
remaining	O
undiagnosed	O
or	O
with	O
delayed	O
diagnosis	O
in	O
the	O
absence	O
of	O
sonography	B-Application
.	O
</s>
<s>
It	O
is	O
currently	O
believed	O
that	O
the	O
risk	O
of	O
delayed	O
diagnosis	O
is	O
greater	O
than	O
the	O
small	O
risk	O
,	O
if	O
any	O
,	O
associated	O
with	O
undergoing	O
an	O
ultrasound	B-Application
scan	I-Application
.	O
</s>
<s>
Obstetric	O
ultrasound	B-Application
is	O
primarily	O
used	O
to	O
:	O
</s>
<s>
Figures	O
released	O
for	O
the	O
period	O
2005	O
–	O
2006	O
by	O
the	O
UK	O
Government	O
(	O
Department	O
of	O
Health	O
)	O
show	O
that	O
non-obstetric	O
ultrasound	B-Application
examinations	O
constituted	O
more	O
than	O
65%	O
of	O
the	O
total	O
number	O
of	O
ultrasound	B-Application
scans	I-Application
conducted	O
.	O
</s>
<s>
Blood	O
velocity	O
can	O
be	O
measured	O
in	O
various	O
blood	O
vessels	O
,	O
such	O
as	O
middle	O
cerebral	O
artery	O
or	O
descending	O
aorta	O
,	O
by	O
relatively	O
inexpensive	O
and	O
low	O
risk	O
ultrasound	B-Application
Doppler	O
probes	O
attached	O
to	O
portable	B-Algorithm
monitors	O
.	O
</s>
<s>
Common	O
examples	O
are	O
,	O
Transcranial	O
Doppler	O
,	O
Esophageal	O
Doppler	O
and	O
Suprasternal	B-Algorithm
Doppler	I-Algorithm
.	O
</s>
<s>
Most	O
structures	O
of	O
the	O
neck	O
,	O
including	O
the	O
thyroid	O
and	O
parathyroid	O
glands	O
,	O
lymph	O
nodes	O
,	O
and	O
salivary	O
glands	O
,	O
are	O
well-visualized	O
by	O
high-frequency	O
ultrasound	B-Application
with	O
exceptional	O
anatomic	O
detail	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
the	O
preferred	O
imaging	B-Application
modality	O
for	O
thyroid	O
tumors	O
and	O
lesions	O
,	O
and	O
its	O
use	O
is	O
important	O
in	O
the	O
evaluation	O
,	O
preoperative	O
planning	O
,	O
and	O
postoperative	O
surveillance	O
of	O
patients	O
with	O
thyroid	O
cancer	O
.	O
</s>
<s>
Many	O
other	O
benign	O
and	O
malignant	O
conditions	O
in	O
the	O
head	O
and	O
neck	O
can	O
be	O
differentiated	O
,	O
evaluated	O
,	O
and	O
managed	O
with	O
the	O
help	O
of	O
diagnostic	B-Application
ultrasound	I-Application
and	O
ultrasound-guided	O
procedures	O
.	O
</s>
<s>
It	O
can	O
be	O
performed	O
through	O
the	O
soft	O
spots	O
in	O
the	O
skull	O
of	O
a	O
newborn	O
infant	O
(	O
Fontanelle	O
)	O
until	O
these	O
completely	O
close	O
at	O
about	O
1	O
year	O
of	O
age	O
by	O
which	O
time	O
they	O
have	O
formed	O
a	O
virtually	O
impenetrable	O
acoustic	O
barrier	O
to	O
ultrasound	B-Application
.	O
</s>
<s>
The	O
most	O
common	O
site	O
for	O
cranial	B-Algorithm
ultrasound	I-Algorithm
is	O
the	O
anterior	O
fontanelle	O
.	O
</s>
<s>
In	O
ophthalmology	O
and	O
optometry	O
,	O
there	O
are	O
two	O
major	O
forms	O
of	O
eye	O
exam	O
using	O
ultrasound	B-Application
:	O
</s>
<s>
A-scan	B-Algorithm
ultrasound	I-Algorithm
biometry	I-Algorithm
,	O
is	O
commonly	O
referred	O
to	O
as	O
an	O
A-scan	B-Algorithm
(	O
amplitude	O
scan	O
)	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
used	O
to	O
assess	O
the	O
lungs	O
in	O
a	O
variety	O
of	O
settings	O
including	O
critical	O
care	O
,	O
emergency	O
medicine	O
,	O
trauma	O
surgery	O
,	O
as	O
well	O
as	O
general	O
medicine	O
.	O
</s>
<s>
This	O
imaging	B-Application
modality	O
is	O
used	O
at	O
the	O
bedside	O
or	O
examination	O
table	O
to	O
evaluate	O
a	O
number	O
of	O
different	O
lung	O
abnormalities	O
as	O
well	O
as	O
to	O
guide	O
procedures	O
such	O
as	O
thoracentesis	O
,	O
(	O
drainage	O
of	O
pleural	O
fluid	O
(	O
effusion	O
)	O
)	O
,	O
needle	O
aspiration	O
biopsy	O
,	O
and	O
catheter	O
placement	O
.	O
</s>
<s>
Although	O
air	O
present	O
in	O
the	O
lungs	O
does	O
not	O
allow	O
good	O
penetration	O
of	O
ultrasound	B-Application
waves	O
,	O
interpretation	O
of	O
specific	O
artifacts	O
created	O
on	O
the	O
lung	O
surface	O
can	O
be	O
used	O
to	O
detect	O
abnormalities	O
.	O
</s>
<s>
These	O
two	O
surfaces	O
are	O
typically	O
pushed	O
together	O
and	O
make	O
up	O
the	O
pleural	O
line	O
,	O
which	O
is	O
the	O
basis	O
of	O
lung	O
(	O
or	O
pleural	O
)	O
ultrasound	B-Application
.	O
</s>
<s>
On	O
ultrasound	B-Application
,	O
it	O
is	O
visualized	O
as	O
a	O
hyperechoic	O
(	O
bright	O
white	O
)	O
horizontal	O
line	O
if	O
the	O
ultrasound	B-Algorithm
probe	I-Algorithm
is	O
applied	O
perpendicularly	O
to	O
the	O
skin	O
.	O
</s>
<s>
Artifacts	O
:	O
Lung	B-Application
ultrasound	I-Application
relies	O
on	O
artifacts	O
,	O
which	O
would	O
otherwise	O
be	O
considered	O
a	O
hindrance	O
in	O
imaging	B-Application
.	O
</s>
<s>
Air	O
blocks	O
the	O
ultrasound	B-Application
beam	O
and	O
thus	O
visualizing	O
healthy	O
lung	O
tissue	O
itself	O
with	O
this	O
mode	O
of	O
imaging	B-Application
is	O
not	O
practical	O
.	O
</s>
<s>
Consequently	O
,	O
physicians	O
and	O
sonographers	O
have	O
learned	O
to	O
recognize	O
patterns	O
that	O
ultrasound	B-Application
beams	O
create	O
when	O
imaging	B-Application
healthy	O
versus	O
diseased	O
lung	O
tissue	O
.	O
</s>
<s>
Three	O
commonly	O
seen	O
and	O
utilized	O
artifacts	O
in	O
lung	B-Application
ultrasound	I-Application
include	O
lung	O
sliding	O
,	O
A-lines	O
,	O
and	O
B-lines	O
.	O
</s>
<s>
§	O
A-lines	O
:	O
When	O
the	O
ultrasound	B-Application
beam	O
makes	O
contact	O
with	O
the	O
pleural	O
line	O
,	O
it	O
is	O
reflected	O
back	O
creating	O
a	O
bright	O
white	O
horizontal	O
line	O
.	O
</s>
<s>
Ultimately	O
,	O
A-lines	O
are	O
a	O
reflection	O
of	O
the	O
ultrasound	B-Application
beam	O
from	O
the	O
pleura	O
with	O
the	O
space	O
between	O
A-lines	O
corresponding	O
to	O
the	O
distance	O
between	O
the	O
parietal	O
pleura	O
and	O
the	O
skin	O
surface	O
.	O
</s>
<s>
They	O
are	O
visualized	O
as	O
hyperechoic	O
vertical	O
lines	O
extending	O
from	O
the	O
pleura	O
to	O
the	O
edge	O
of	O
the	O
ultrasound	B-Application
screen	O
.	O
</s>
<s>
Pulmonary	O
edema	O
:	O
Lung	B-Application
ultrasound	I-Application
has	O
been	O
shown	O
to	O
be	O
very	O
sensitive	O
for	O
the	O
detection	O
of	O
pulmonary	O
edema	O
.	O
</s>
<s>
It	O
allows	O
for	O
improvement	O
in	O
diagnosis	O
and	O
management	O
of	O
critically	O
ill	O
patients	O
,	O
particularly	O
when	O
used	O
in	O
combination	O
with	O
echocardiography	B-Application
.	O
</s>
<s>
The	O
sonographic	B-Application
feature	O
that	O
is	O
present	O
in	O
pulmonary	O
edema	O
is	O
multiple	O
B-lines	O
.	O
</s>
<s>
Additionally	O
,	O
it	O
is	O
important	O
to	O
note	O
that	O
there	O
are	O
multiple	O
types	O
of	O
interactions	O
between	O
the	O
pleural	O
surface	O
and	O
the	O
ultrasound	B-Application
wave	O
that	O
can	O
generate	O
artifacts	O
with	O
some	O
similarity	O
to	O
B-lines	O
but	O
which	O
do	O
not	O
have	O
pathologic	O
significance	O
.	O
</s>
<s>
Pneumothorax	O
:	O
In	O
clinical	O
settings	O
when	O
pneumothorax	O
is	O
suspected	O
,	O
lung	B-Application
ultrasound	I-Application
can	O
aid	O
in	O
diagnosis	O
.	O
</s>
<s>
In	O
pneumothorax	O
,	O
air	O
is	O
present	O
between	O
the	O
two	O
layers	O
of	O
the	O
pleura	O
and	O
lung	O
sliding	O
on	O
ultrasound	B-Application
is	O
therefore	O
absent	O
.	O
</s>
<s>
The	O
negative	O
predictive	O
value	O
for	O
lung	O
sliding	O
on	O
ultrasound	B-Application
is	O
reported	O
as	O
99.2	O
–	O
100%	O
-	O
briefly	O
,	O
if	O
lung	O
sliding	O
is	O
present	O
,	O
a	O
pneumothorax	O
is	O
effectively	O
ruled	O
out	O
.	O
</s>
<s>
Pleural	O
effusion	O
:	O
Lung	B-Application
ultrasound	I-Application
is	O
a	O
cost-effective	O
,	O
safe	O
,	O
and	O
non-invasive	O
imaging	B-Application
method	O
that	O
can	O
aid	O
in	O
the	O
prompt	O
visualization	O
and	O
diagnosis	O
of	O
pleural	O
effusions	O
.	O
</s>
<s>
Consequently	O
,	O
lung	B-Application
ultrasound	I-Application
can	O
be	O
an	O
additional	O
tool	O
to	O
augment	O
plain	O
chest	O
Xray	O
and	O
chest	O
CT	O
.	O
Pleural	O
effusions	O
on	O
ultrasound	B-Application
appear	O
as	O
structural	O
images	O
within	O
the	O
thorax	O
rather	O
than	O
an	O
artifact	O
.	O
</s>
<s>
In	O
critically	O
ill	O
patients	O
with	O
pleural	O
effusion	O
,	O
ultrasound	B-Application
may	O
guide	O
procedures	O
including	O
needle	O
insertion	O
,	O
thoracentesis	O
,	O
and	O
chest-tube	O
insertion	O
.	O
</s>
<s>
Lung	O
cancer	O
staging	O
:	O
In	O
pulmonology	O
,	O
endobronchial	O
ultrasound	B-Application
(	O
EBUS	O
)	O
probes	O
are	O
applied	O
to	O
standard	O
flexible	O
endoscopic	O
probes	O
and	O
used	O
by	O
pulmonologists	O
to	O
allow	O
for	O
direct	O
visualization	O
of	O
endobronchial	O
lesions	O
and	O
lymph	O
nodes	O
prior	O
to	O
transbronchial	O
needle	O
aspiration	O
.	O
</s>
<s>
COVID-19	O
:	O
Lung	B-Application
ultrasound	I-Application
has	O
proved	O
useful	O
in	O
the	O
diagnosis	O
of	O
COVID-19	O
especially	O
in	O
cases	O
where	O
other	O
investigations	O
are	O
not	O
available	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
routinely	O
used	O
in	O
urology	O
to	O
determine	O
the	O
amount	O
of	O
fluid	O
retained	O
in	O
a	O
patient	O
's	O
bladder	O
.	O
</s>
<s>
There	O
are	O
two	O
methods	O
of	O
performing	O
pelvic	O
sonography	B-Application
–	O
externally	O
or	O
internally	O
.	O
</s>
<s>
Sonographic	B-Application
imaging	B-Application
of	O
the	O
pelvic	O
floor	O
can	O
produce	O
important	O
diagnostic	O
information	O
regarding	O
the	O
precise	O
relationship	O
of	O
abnormal	O
structures	O
with	O
other	O
pelvic	O
organs	O
and	O
it	O
represents	O
a	O
useful	O
hint	O
to	O
treat	O
patients	O
with	O
symptoms	O
related	O
to	O
pelvic	O
prolapse	O
,	O
double	O
incontinence	O
and	O
obstructed	O
defecation	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
an	O
excellent	O
method	O
for	O
the	O
study	O
of	O
the	O
penis	O
,	O
such	O
as	O
indicated	O
in	O
trauma	O
,	O
priapism	O
,	O
erectile	O
dysfunction	O
or	O
suspected	O
Peyronie	O
's	O
disease	O
.	O
</s>
<s>
Musculoskeletal	O
ultrasound	B-Application
is	O
used	O
to	O
examine	O
tendons	O
,	O
muscles	O
,	O
nerves	O
,	O
ligaments	O
,	O
soft	O
tissue	O
masses	O
,	O
and	O
bone	O
surfaces	O
.	O
</s>
<s>
It	O
is	O
an	O
alternative	O
or	O
supplement	O
to	O
x-ray	B-Library
imaging	B-Application
in	O
detecting	O
fractures	O
of	O
the	O
wrist	O
,	O
elbow	O
and	O
shoulder	O
for	O
patients	O
up	O
to	O
12	O
years	O
(	O
Fracture	O
sonography	B-Application
)	O
.	O
</s>
<s>
Ultrasound	B-Application
can	O
also	O
be	O
used	O
for	O
needle	O
guidance	O
in	O
muscle	O
or	O
joint	O
injections	O
,	O
as	O
in	O
ultrasound-guided	O
hip	O
joint	O
injection	O
.	O
</s>
<s>
The	O
kidneys	O
are	O
easily	O
examined	O
,	O
and	O
most	O
pathological	O
changes	O
are	O
distinguishable	O
with	O
ultrasound	B-Application
.	O
</s>
<s>
Using	O
B-mode	O
imaging	B-Application
,	O
assessment	O
of	O
renal	O
anatomy	O
is	O
easily	O
performed	O
,	O
and	O
US	O
is	O
often	O
used	O
as	O
image	O
guidance	O
for	O
renal	O
interventions	O
.	O
</s>
<s>
Furthermore	O
,	O
novel	O
applications	O
in	O
renal	O
US	O
have	O
been	O
introduced	O
with	O
contrast-enhanced	O
ultrasound	B-Application
(	O
CEUS	O
)	O
,	O
elastography	B-Algorithm
and	O
fusion	O
imaging	B-Application
.	O
</s>
<s>
However	O
,	O
renal	O
US	O
has	O
certain	O
limitations	O
,	O
and	O
other	O
modalities	O
,	O
such	O
as	O
CT	O
(	O
CECT	O
)	O
and	O
MRI	O
,	O
should	O
be	O
considered	O
for	O
supplementary	O
imaging	B-Application
in	O
assessing	O
renal	O
disease	O
.	O
</s>
<s>
In	O
these	O
challenging	O
situations	O
,	O
the	O
insertion	O
of	O
a	O
catheter	O
into	O
a	O
vein	O
has	O
been	O
greatly	O
assisted	O
by	O
the	O
use	O
of	O
ultrasound	B-Application
.	O
</s>
<s>
The	O
ultrasound	B-Application
unit	O
may	O
be	O
'	O
cart-based	O
'	O
or	O
'	O
handheld	O
 '	O
using	O
a	O
linear	O
transducer	B-Algorithm
with	O
a	O
frequency	O
of	O
10	O
to	O
15	O
megahertz	O
.	O
</s>
<s>
The	O
transducer	B-Algorithm
may	O
be	O
placed	O
longitudinally	O
or	O
transversely	O
over	O
the	O
chosen	O
vein	O
.	O
</s>
<s>
Ultrasound	B-Application
training	O
for	O
intravenous	O
cannulation	O
is	O
offered	O
in	O
most	O
ultrasound	B-Application
training	O
programs	O
.	O
</s>
<s>
The	O
creation	O
of	O
an	O
image	O
from	O
sound	O
has	O
three	O
steps	O
–	O
transmitting	O
a	O
sound	O
wave	O
,	O
receiving	O
echoes	B-Protocol
,	O
and	O
interpreting	O
those	O
echoes	B-Protocol
.	O
</s>
<s>
A	O
sound	O
wave	O
is	O
typically	O
produced	O
by	O
a	O
piezoelectric	O
transducer	B-Algorithm
encased	O
in	O
a	O
plastic	O
housing	O
.	O
</s>
<s>
Strong	O
,	O
short	O
electrical	O
pulses	O
from	O
the	O
ultrasound	B-Application
machine	I-Application
drive	O
the	O
transducer	B-Algorithm
at	O
the	O
desired	O
frequency	O
.	O
</s>
<s>
Older	O
technology	O
transducers	B-Algorithm
focused	O
their	O
beam	O
with	O
physical	O
lenses	O
.	O
</s>
<s>
Contemporary	O
technology	O
transducers	B-Algorithm
use	O
digital	B-Algorithm
antenna	I-Algorithm
array	I-Algorithm
techniques	O
(	O
piezoelectric	O
elements	O
in	O
the	O
transducer	B-Algorithm
produce	O
echoes	B-Protocol
at	O
different	O
times	O
)	O
to	O
enable	O
the	O
ultrasound	B-Application
machine	I-Application
to	O
change	O
the	O
direction	O
and	O
depth	O
of	O
focus	O
.	O
</s>
<s>
Near	O
the	O
transducer	B-Algorithm
,	O
the	O
width	O
of	O
the	O
ultrasound	B-Application
beam	O
almost	O
equals	O
to	O
the	O
width	O
of	O
the	O
transducer	B-Algorithm
,	O
after	O
reaching	O
a	O
distance	O
from	O
the	O
transducer	B-Algorithm
(	O
near	O
zone	O
length	O
or	O
Fresnel	O
zone	O
)	O
,	O
the	O
beam	O
width	O
narrows	O
to	O
half	O
of	O
the	O
transducer	B-Algorithm
width	O
,	O
and	O
after	O
that	O
the	O
width	O
increases	O
(	O
far	O
zone	O
length	O
or	O
Fraunhofer	O
's	O
zone	O
)	O
,	O
where	O
the	O
lateral	O
resolution	O
decreases	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
wider	O
the	O
transducer	B-Algorithm
width	O
and	O
the	O
higher	O
the	O
frequency	O
of	O
ultrasound	B-Application
,	O
the	O
longer	O
the	O
Fresnel	O
zone	O
,	O
and	O
the	O
lateral	O
resolution	O
can	O
be	O
maintained	O
at	O
a	O
greater	O
depth	O
from	O
the	O
transducer	B-Algorithm
.	O
</s>
<s>
Ultrasound	B-Application
waves	O
travel	O
in	O
pulses	O
.	O
</s>
<s>
Therefore	O
,	O
a	O
shorter	O
pulse	O
length	O
requires	O
higher	O
bandwidth	O
(	O
greater	O
number	O
of	O
frequencies	O
)	O
to	O
constitute	O
the	O
ultrasound	B-Application
pulse	O
.	O
</s>
<s>
As	O
stated	O
,	O
the	O
sound	O
is	O
focused	O
either	O
by	O
the	O
shape	O
of	O
the	O
transducer	B-Algorithm
,	O
a	O
lens	O
in	O
front	O
of	O
the	O
transducer	B-Algorithm
,	O
or	O
a	O
complex	O
set	O
of	O
control	O
pulses	O
from	O
the	O
ultrasound	B-Application
scanner	I-Application
,	O
in	O
the	O
beamforming	B-Algorithm
or	O
spatial	O
filtering	O
technique	O
.	O
</s>
<s>
This	O
focusing	O
produces	O
an	O
arc-shaped	O
sound	O
wave	O
from	O
the	O
face	O
of	O
the	O
transducer	B-Algorithm
.	O
</s>
<s>
Materials	O
on	O
the	O
face	O
of	O
the	O
transducer	B-Algorithm
enable	O
the	O
sound	O
to	O
be	O
transmitted	O
efficiently	O
into	O
the	O
body	O
(	O
often	O
a	O
rubbery	O
coating	O
,	O
a	O
form	O
of	O
impedance	O
matching	O
)	O
.	O
</s>
<s>
In	O
addition	O
,	O
a	O
water-based	O
gel	O
is	O
placed	O
between	O
the	O
patient	O
's	O
skin	O
and	O
the	O
probe	O
to	O
facilitate	O
ultrasound	B-Application
transmission	O
into	O
the	O
body	O
.	O
</s>
<s>
This	O
is	O
because	O
air	O
causes	O
total	O
reflection	O
of	O
ultrasound	B-Application
;	O
impeding	O
the	O
transmission	O
of	O
ultrasound	B-Application
into	O
the	O
body	O
.	O
</s>
<s>
Some	O
of	O
the	O
reflections	O
return	O
to	O
the	O
transducer	B-Algorithm
.	O
</s>
<s>
The	O
return	O
of	O
the	O
sound	O
wave	O
to	O
the	O
transducer	B-Algorithm
results	O
in	O
the	O
same	O
process	O
as	O
sending	O
the	O
sound	O
wave	O
,	O
in	O
reverse	O
.	O
</s>
<s>
The	O
returned	O
sound	O
wave	O
vibrates	O
the	O
transducer	B-Algorithm
and	O
the	O
transducer	B-Algorithm
turns	O
the	O
vibrations	O
into	O
electrical	O
pulses	O
that	O
travel	O
to	O
the	O
ultrasonic	O
scanner	O
where	O
they	O
are	O
processed	O
and	O
transformed	O
into	O
a	O
digital	O
image	O
.	O
</s>
<s>
To	O
make	O
an	O
image	O
,	O
the	O
ultrasound	B-Application
scanner	I-Application
must	O
determine	O
two	O
characteristics	O
from	O
each	O
received	O
echo	B-Protocol
:	O
</s>
<s>
How	O
long	O
it	O
took	O
the	O
echo	B-Protocol
to	O
be	O
received	O
from	O
when	O
the	O
sound	O
was	O
transmitted	O
.	O
</s>
<s>
How	O
strong	O
the	O
echo	B-Protocol
was	O
.	O
</s>
<s>
Once	O
the	O
ultrasonic	O
scanner	O
determines	O
these	O
two	O
,	O
it	O
can	O
locate	O
which	O
pixel	B-Algorithm
in	O
the	O
image	O
to	O
illuminate	O
and	O
with	O
what	O
intensity	O
.	O
</s>
<s>
First	O
picture	O
a	O
long	O
,	O
flat	O
transducer	B-Algorithm
at	O
the	O
top	O
of	O
the	O
sheet	O
.	O
</s>
<s>
Listen	O
at	O
each	O
column	O
for	O
any	O
return	O
echoes	B-Protocol
.	O
</s>
<s>
When	O
an	O
echo	B-Protocol
is	O
heard	O
,	O
note	O
how	O
long	O
it	O
took	O
for	O
the	O
echo	B-Protocol
to	O
return	O
.	O
</s>
<s>
The	O
strength	O
of	O
the	O
echo	B-Protocol
determines	O
the	O
brightness	O
setting	O
for	O
that	O
cell	O
(	O
white	O
for	O
a	O
strong	O
echo	B-Protocol
,	O
black	O
for	O
a	O
weak	O
echo	B-Protocol
,	O
and	O
varying	O
shades	O
of	O
grey	O
for	O
everything	O
in	O
between	O
.	O
)	O
</s>
<s>
When	O
all	O
the	O
echoes	B-Protocol
are	O
recorded	O
on	O
the	O
sheet	O
,	O
a	O
greyscale	O
image	O
has	O
been	O
accomplished	O
.	O
</s>
<s>
Images	O
from	O
the	O
ultrasound	B-Application
scanner	I-Application
are	O
transferred	O
and	O
displayed	O
using	O
the	O
DICOM	B-Algorithm
standard	O
.	O
</s>
<s>
Ultrasonography	O
(	O
sonography	B-Application
)	O
uses	O
a	O
probe	O
containing	O
multiple	O
acoustic	O
transducers	B-Algorithm
to	O
send	O
pulses	O
of	O
sound	O
into	O
a	O
material	O
.	O
</s>
<s>
Whenever	O
a	O
sound	O
wave	O
encounters	O
a	O
material	O
with	O
a	O
different	O
density	O
(	O
acoustical	O
impedance	O
)	O
,	O
some	O
of	O
the	O
sound	O
wave	O
is	O
scattered	O
but	O
part	O
is	O
reflected	O
back	O
to	O
the	O
probe	O
and	O
is	O
detected	O
as	O
an	O
echo	B-Protocol
.	O
</s>
<s>
The	O
time	O
it	O
takes	O
for	O
the	O
echo	B-Protocol
to	O
travel	O
back	O
to	O
the	O
probe	O
is	O
measured	O
and	O
used	O
to	O
calculate	O
the	O
depth	O
of	O
the	O
tissue	O
interface	O
causing	O
the	O
echo	B-Protocol
.	O
</s>
<s>
The	O
greater	O
the	O
difference	O
between	O
acoustic	O
impedances	O
,	O
the	O
larger	O
the	O
echo	B-Protocol
is	O
.	O
</s>
<s>
The	O
frequencies	O
used	O
for	O
medical	B-Application
imaging	I-Application
are	O
generally	O
in	O
the	O
range	O
of	O
1	O
to	O
18MHz	O
Higher	O
frequencies	O
have	O
a	O
correspondingly	O
smaller	O
wavelength	O
,	O
and	O
can	O
be	O
used	O
to	O
make	O
more	O
detailed	O
sonograms	O
.	O
</s>
<s>
Penetrating	O
deep	O
into	O
the	O
body	O
with	O
sonography	B-Application
is	O
difficult	O
.	O
</s>
<s>
Some	O
acoustic	O
energy	O
is	O
lost	O
each	O
time	O
an	O
echo	B-Protocol
is	O
formed	O
,	O
but	O
most	O
of	O
it	O
(	O
approximately	O
)	O
is	O
lost	O
from	O
acoustic	O
absorption	O
.	O
</s>
<s>
However	O
,	O
the	O
sonographic	B-Application
instrument	O
assumes	O
that	O
the	O
acoustic	O
velocity	O
is	O
constant	O
at	O
1540m/s	O
.	O
</s>
<s>
A	O
transducer	B-Algorithm
may	O
be	O
swept	O
mechanically	O
by	O
rotating	O
or	O
swinging	O
or	O
a	O
1-D	O
phased	O
array	O
transducer	B-Algorithm
may	O
be	O
used	O
to	O
sweep	O
the	O
beam	O
electronically	O
.	O
</s>
<s>
Commonly	O
a	O
specialized	O
probe	O
that	O
mechanically	O
scans	O
a	O
conventional	O
2-D	O
image	O
transducer	B-Algorithm
is	O
used	O
.	O
</s>
<s>
Recently	O
,	O
2-D	O
phased	O
array	O
transducers	B-Algorithm
that	O
can	O
sweep	O
the	O
beam	O
in	O
3-D	O
have	O
been	O
developed	O
.	O
</s>
<s>
Doppler	B-Algorithm
ultrasonography	I-Algorithm
is	O
used	O
to	O
study	O
blood	O
flow	O
and	O
muscle	O
motion	O
.	O
</s>
<s>
Colors	O
may	O
alternatively	O
be	O
used	O
to	O
represent	O
the	O
amplitudes	O
of	O
the	O
received	O
echoes	B-Protocol
.	O
</s>
<s>
An	O
additional	O
expansion	O
of	O
ultrasound	B-Application
is	O
bi-planar	O
ultrasound	B-Application
,	O
in	O
which	O
the	O
probe	O
has	O
two	O
2D	O
planes	O
perpendicular	O
to	O
each	O
other	O
,	O
providing	O
more	O
efficient	O
localization	O
and	O
detection	O
.	O
</s>
<s>
In	O
3D	B-Algorithm
ultrasound	I-Algorithm
,	O
many	O
2D	O
planes	O
are	O
digitally	O
added	O
together	O
to	O
create	O
a	O
3-dimensional	O
image	O
of	O
the	O
object	O
.	O
</s>
<s>
Doppler	B-Algorithm
ultrasonography	I-Algorithm
employs	O
the	O
Doppler	O
effect	O
to	O
assess	O
whether	O
structures	O
(	O
usually	O
blood	O
)	O
are	O
moving	O
towards	O
or	O
away	O
from	O
the	O
probe	O
,	O
and	O
their	O
relative	O
velocity	O
.	O
</s>
<s>
Color	B-Algorithm
Doppler	I-Algorithm
is	O
the	O
measurement	O
of	O
velocity	O
by	O
color	O
scale	O
.	O
</s>
<s>
Color	B-Algorithm
Doppler	I-Algorithm
images	O
are	O
generally	O
combined	O
with	O
gray	O
scale	O
(	O
B-mode	O
)	O
images	O
to	O
display	O
duplex	B-Algorithm
ultrasonography	I-Algorithm
images	O
.	O
</s>
<s>
Doppler	O
echocardiography	B-Application
is	O
the	O
use	O
of	O
Doppler	B-Algorithm
ultrasonography	I-Algorithm
to	O
examine	O
the	O
heart	O
.	O
</s>
<s>
An	O
echocardiogram	B-Application
can	O
,	O
within	O
certain	O
limits	O
,	O
produce	O
accurate	O
assessment	O
of	O
the	O
direction	O
of	O
blood	O
flow	O
and	O
the	O
velocity	O
of	O
blood	O
and	O
cardiac	O
tissue	O
at	O
any	O
arbitrary	O
point	O
using	O
the	O
Doppler	O
effect	O
.	O
</s>
<s>
Contrast-enhanced	O
ultrasound	B-Application
using	O
gas-filled	O
microbubble	O
contrast	B-Algorithm
media	I-Algorithm
can	O
be	O
used	O
to	O
improve	O
velocity	O
or	O
other	O
flow-related	O
measurements	O
of	O
interest	O
.	O
</s>
<s>
Transcranial	O
Doppler	O
(	O
TCD	O
)	O
and	O
transcranial	O
color	B-Algorithm
Doppler	I-Algorithm
(	O
TCCD	O
)	O
,	O
measure	O
the	O
velocity	O
of	O
blood	O
flow	O
through	O
the	O
brain	O
's	O
blood	O
vessels	O
through	O
the	O
cranium	O
.	O
</s>
<s>
A	O
contrast	B-Algorithm
medium	I-Algorithm
for	O
medical	B-Application
ultrasonography	I-Application
is	O
a	O
formulation	O
of	O
encapsulated	O
gaseous	O
microbubbles	O
to	O
increase	O
echogenicity	O
of	O
blood	O
,	O
discovered	O
by	O
Dr.	O
Raymond	O
Gramiak	O
in	O
1968	O
and	O
named	O
contrast-enhanced	O
ultrasound	B-Application
.	O
</s>
<s>
This	O
contrast	O
medical	B-Application
imaging	I-Application
modality	O
is	O
used	O
throughout	O
the	O
world	O
,	O
for	O
echocardiography	B-Application
in	O
particular	O
in	O
the	O
United	O
States	O
and	O
for	O
ultrasound	B-Application
radiology	O
in	O
Europe	O
and	O
Asia	O
.	O
</s>
<s>
Microbubbles-based	O
contrast	B-Algorithm
media	I-Algorithm
is	O
administrated	O
intravenously	O
into	O
the	O
patient	O
blood	O
stream	O
during	O
the	O
ultrasonography	O
examination	O
.	O
</s>
<s>
An	O
ultrasound	B-Application
contrast	B-Algorithm
media	I-Algorithm
is	O
therefore	O
purely	O
intravascular	O
,	O
making	O
it	O
an	O
ideal	O
agent	O
to	O
image	O
organ	O
microvasculature	O
for	O
diagnostic	O
purposes	O
.	O
</s>
<s>
Other	O
clinical	O
applications	O
using	O
contrast	O
exist	O
,	O
as	O
in	O
echocardiography	B-Application
to	O
improve	O
delineation	O
of	O
left	O
ventricle	O
for	O
visualizing	O
contractibility	O
of	O
heart	O
muscle	O
after	O
a	O
myocardial	O
infarction	O
.	O
</s>
<s>
Finally	O
,	O
applications	O
in	O
quantitative	O
perfusion	O
(	O
relative	O
measurement	O
of	O
blood	O
flow	O
)	O
have	O
emerged	O
for	O
identifying	O
early	O
patient	O
response	O
to	O
anti-cancerous	O
drug	O
treatment	O
(	O
methodology	O
and	O
clinical	O
study	O
by	O
Dr.	O
Nathalie	O
Lassau	O
in	O
2011	O
)	O
,	O
enabling	O
the	O
best	O
oncological	O
therapeutic	B-Algorithm
options	O
to	O
be	O
determined	O
.	O
</s>
<s>
In	O
oncological	O
practice	O
of	O
medical	O
contrast	O
ultrasonography	O
,	O
clinicians	O
use	O
'	O
parametric	O
imaging	B-Application
of	O
vascular	O
signatures	O
 '	O
invented	O
by	O
Dr.	O
Nicolas	O
Rognin	O
in	O
2010	O
.	O
</s>
<s>
This	O
method	O
is	O
based	O
on	O
medical	O
computational	O
science	O
to	O
analyze	O
a	O
time	O
sequence	O
of	O
ultrasound	B-Application
contrast	O
images	O
,	O
a	O
digital	O
video	O
recorded	O
in	O
real-time	O
during	O
patient	O
examination	O
.	O
</s>
<s>
Two	O
consecutive	O
signal	O
processing	O
steps	O
are	O
applied	O
to	O
each	O
pixel	B-Algorithm
of	O
the	O
tumor	O
:	O
</s>
<s>
Once	O
signal	O
processing	O
in	O
each	O
pixel	B-Algorithm
is	O
completed	O
,	O
a	O
color	O
spatial	O
map	O
of	O
the	O
parameter	O
is	O
displayed	O
on	O
a	O
computer	B-Device
monitor	I-Device
,	O
summarizing	O
all	O
vascular	O
information	O
of	O
the	O
tumor	O
in	O
a	O
single	O
image	O
called	O
a	O
parametric	O
image	O
(	O
see	O
last	O
figure	O
of	O
press	O
article	O
as	O
clinical	O
examples	O
)	O
.	O
</s>
<s>
The	O
main	O
clinical	O
benefits	O
are	O
to	O
avoid	O
a	O
systemic	O
biopsy	O
(	O
with	O
inherent	O
risks	O
of	O
invasive	O
procedures	O
)	O
of	O
benign	O
tumors	O
or	O
a	O
CT	O
scan	O
examination	O
exposing	O
the	O
patient	O
to	O
X-ray	B-Library
radiation	O
.	O
</s>
<s>
The	O
parametric	O
imaging	B-Application
of	O
vascular	O
signatures	O
method	O
proved	O
to	O
be	O
effective	O
in	O
humans	O
for	O
characterization	O
of	O
tumors	O
in	O
the	O
liver	O
.	O
</s>
<s>
The	O
current	O
future	O
of	O
contrast	O
ultrasonography	O
is	O
in	O
molecular	B-Algorithm
imaging	I-Algorithm
with	O
potential	O
clinical	O
applications	O
expected	O
in	O
cancer	O
screening	O
to	O
detect	O
malignant	O
tumors	O
at	O
their	O
earliest	O
stage	O
of	O
appearance	O
.	O
</s>
<s>
Molecular	O
ultrasonography	O
(	O
or	O
ultrasound	B-Application
molecular	B-Algorithm
imaging	I-Algorithm
)	O
uses	O
targeted	O
microbubbles	O
originally	O
designed	O
by	O
Dr	O
Alexander	O
Klibanov	O
in	O
1997	O
;	O
such	O
targeted	O
microbubbles	O
specifically	O
bind	O
or	O
adhere	O
to	O
tumoral	O
microvessels	O
by	O
targeting	O
biomolecular	O
cancer	O
expression	O
(	O
overexpression	O
of	O
certain	O
biomolecules	O
that	O
occurs	O
during	O
neo-angiogenesis	O
or	O
inflammation	O
in	O
malignant	O
tumors	O
)	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
a	O
few	O
minutes	O
after	O
their	O
injection	O
in	O
blood	O
circulation	O
,	O
the	O
targeted	O
microbubbles	O
accumulate	O
in	O
the	O
malignant	O
tumor	O
;	O
facilitating	O
its	O
localization	O
in	O
a	O
unique	O
ultrasound	B-Application
contrast	O
image	O
.	O
</s>
<s>
In	O
molecular	O
ultrasonography	O
,	O
the	O
technique	O
of	O
acoustic	O
radiation	O
force	O
(	O
also	O
used	O
for	O
shear	O
wave	O
elastography	B-Algorithm
)	O
is	O
applied	O
in	O
order	O
to	O
literally	O
push	O
the	O
targeted	O
microbubbles	O
towards	O
microvessels	O
wall	O
;	O
first	O
demonstrated	O
by	O
Dr.	O
Paul	O
Dayton	O
in	O
1999	O
.	O
</s>
<s>
At	O
the	O
stage	O
of	O
scientific	O
preclinical	O
research	O
,	O
the	O
technique	O
of	O
acoustic	O
radiation	O
force	O
was	O
implemented	O
as	O
a	O
prototype	O
in	O
clinical	O
ultrasound	B-Application
systems	O
and	O
validated	O
in	O
vivo	O
in	O
2D	O
and	O
3D	O
imaging	B-Application
modes	O
.	O
</s>
<s>
Ultrasound	B-Application
is	O
also	O
used	O
for	O
elastography	B-Algorithm
,	O
which	O
is	O
a	O
relatively	O
new	O
imaging	B-Application
modality	O
that	O
maps	O
the	O
elastic	O
properties	O
of	O
soft	O
tissue	O
.	O
</s>
<s>
Elastography	B-Algorithm
is	O
useful	O
in	O
medical	O
diagnoses	O
as	O
it	O
can	O
discern	O
healthy	O
from	O
unhealthy	O
tissue	O
for	O
specific	O
organs/growths	O
.	O
</s>
<s>
There	O
are	O
many	O
ultrasound	B-Algorithm
elastography	I-Algorithm
techniques	O
.	O
</s>
<s>
Thyroid	O
cysts	O
:	O
High	O
frequency	O
thyroid	O
ultrasound	B-Application
(	O
HFUS	O
)	O
can	O
be	O
used	O
to	O
treat	O
several	O
gland	O
conditions	O
.	O
</s>
<s>
With	O
ultrasound	B-Application
guided	O
placement	O
of	O
a	O
25	O
gauge	O
needle	O
within	O
the	O
cyst	O
,	O
and	O
after	O
evacuation	O
of	O
the	O
cyst	O
fluid	O
,	O
about	O
50%	O
of	O
the	O
cyst	O
volume	O
is	O
injected	O
back	O
into	O
the	O
cavity	O
,	O
under	O
strict	O
operator	O
visualization	O
of	O
the	O
needle	O
tip	O
.	O
</s>
<s>
Small	O
amounts	O
of	O
ethanol	O
are	O
injected	O
under	O
ultrasound	B-Application
guided	O
needle	O
placement	O
.	O
</s>
<s>
A	O
power	B-Algorithm
doppler	I-Algorithm
blood	O
flow	O
study	O
is	O
done	O
prior	O
to	O
injection	O
.	O
</s>
<s>
Power	B-Algorithm
doppler	I-Algorithm
visualized	O
blood	O
flow	O
can	O
be	O
eradicated	O
,	O
and	O
there	O
may	O
be	O
a	O
drop	O
in	O
the	O
cancer	O
blood	O
marker	O
test	O
,	O
thyroglobulin	O
,	O
TG	O
,	O
as	O
the	O
node	O
become	O
non-functional	O
.	O
</s>
<s>
A	O
minute	O
amount	O
of	O
methylene	O
dye	O
is	O
injected	O
,	O
under	O
careful	O
ultrasound	B-Application
guided	O
placement	O
of	O
the	O
needle	O
on	O
the	O
anterior	O
surface	O
,	O
but	O
not	O
in	O
the	O
node	O
.	O
</s>
<s>
Joint	O
injections	O
can	O
be	O
guided	O
by	O
medical	B-Application
ultrasound	I-Application
,	O
such	O
as	O
in	O
ultrasound-guided	O
hip	O
joint	O
injections	O
.	O
</s>
<s>
It	O
is	O
used	O
in	O
ultrasonography	B-Algorithm
of	I-Algorithm
deep	I-Algorithm
venous	I-Algorithm
thrombosis	I-Algorithm
,	O
wherein	O
absence	O
of	O
vein	O
compressibility	O
is	O
a	O
strong	O
indicator	O
of	O
thrombosis	O
.	O
</s>
<s>
Panoramic	O
ultrasonography	O
is	O
the	O
digital	O
stitching	B-Algorithm
of	O
multiple	O
ultrasound	B-Application
images	O
into	O
a	O
broader	O
one	O
.	O
</s>
<s>
Multiparametric	O
ultrasonography	O
(	O
mpUSS	O
)	O
combines	O
multiple	O
ultrasound	B-Application
techniques	O
to	O
produce	O
a	O
composite	O
result	O
.	O
</s>
<s>
For	O
example	O
,	O
one	O
study	O
combined	O
B-mode	O
,	O
colour	O
Doppler	O
,	O
real-time	O
elastography	B-Algorithm
,	O
and	O
contrast-enhanced	O
ultrasound	B-Application
,	O
achieving	O
an	O
accuracy	O
similar	O
to	O
that	O
of	O
multiparametric	B-Algorithm
MRI	I-Algorithm
.	O
</s>
<s>
Speed-of-sound	O
(	O
SoS	O
)	O
imaging	B-Application
aims	O
to	O
find	O
the	O
spatial	O
distribution	O
of	O
the	O
SoS	O
within	O
the	O
tissue	O
.	O
</s>
<s>
Compared	O
to	O
shear-wave	O
elastography	B-Algorithm
,	O
SoS	O
imaging	B-Application
has	O
better	O
ex-vivo	O
tissue	O
differentiation	O
for	O
benign	O
and	O
malignant	O
tumors	O
.	O
</s>
<s>
As	O
with	O
all	O
imaging	B-Application
modalities	O
,	O
ultrasonography	O
has	O
positive	O
and	O
negative	O
attributes	O
.	O
</s>
<s>
Live	O
images	O
also	O
permit	O
ultrasound-guided	B-Application
biopsies	I-Application
or	O
injections	O
,	O
which	O
can	O
be	O
cumbersome	O
with	O
other	O
imaging	B-Application
modalities	O
.	O
</s>
<s>
Transducers	B-Algorithm
have	O
become	O
relatively	O
inexpensive	O
compared	O
to	O
other	O
modes	O
of	O
investigation	O
,	O
such	O
as	O
computed	O
X-ray	B-Library
tomography	O
,	O
DEXA	B-Algorithm
or	O
magnetic	O
resonance	O
imaging	B-Application
.	O
</s>
<s>
Spatial	O
resolution	O
is	O
better	O
in	O
high	O
frequency	O
ultrasound	B-Algorithm
transducers	I-Algorithm
than	O
most	O
other	O
imaging	B-Application
modalities	O
.	O
</s>
<s>
Use	O
of	O
an	O
ultrasound	B-Application
research	O
interface	O
can	O
offer	O
a	O
relatively	O
inexpensive	O
,	O
real-time	O
,	O
and	O
flexible	O
method	O
for	O
capturing	O
data	O
required	O
for	O
specific	O
research	O
purposes	O
of	O
tissue	O
characterization	O
and	O
development	O
of	O
new	O
image	O
processing	O
techniques	O
.	O
</s>
<s>
Sonographic	B-Application
devices	O
have	O
trouble	O
penetrating	O
bone	O
.	O
</s>
<s>
For	O
example	O
,	O
sonography	B-Application
of	O
the	O
adult	O
brain	O
is	O
currently	O
very	O
limited	O
.	O
</s>
<s>
Sonography	B-Application
performs	O
very	O
poorly	O
when	O
there	O
is	O
gas	O
between	O
the	O
transducer	B-Algorithm
and	O
the	O
organ	O
of	O
interest	O
,	O
due	O
to	O
the	O
extreme	O
differences	O
in	O
acoustic	O
impedance	O
.	O
</s>
<s>
For	O
example	O
,	O
overlying	O
gas	O
in	O
the	O
gastrointestinal	O
tract	O
often	O
makes	O
ultrasound	B-Application
scanning	I-Application
of	O
the	O
pancreas	O
difficult	O
.	O
</s>
<s>
Lung	O
imaging	B-Application
however	O
can	O
be	O
useful	O
in	O
demarcating	O
pleural	O
effusions	O
,	O
detecting	O
heart	O
failure	O
and	O
pneumonia	O
.	O
</s>
<s>
Even	O
in	O
the	O
absence	O
of	O
bone	O
or	O
air	O
,	O
the	O
depth	O
penetration	O
of	O
ultrasound	B-Application
may	O
be	O
limited	O
depending	O
on	O
the	O
frequency	O
of	O
imaging	B-Application
.	O
</s>
<s>
Consequently	O
,	O
there	O
might	O
be	O
difficulties	O
imaging	B-Application
structures	O
deep	O
in	O
the	O
body	O
,	O
especially	O
in	O
obese	O
patients	O
.	O
</s>
<s>
A	O
lower	O
frequency	O
transducer	B-Algorithm
is	O
required	O
with	O
subsequent	O
lower	O
resolution	O
.	O
</s>
<s>
Ultrasonography	O
is	O
generally	O
considered	O
safe	O
imaging	B-Application
,	O
with	O
the	O
World	O
Health	O
Organizations	O
stating	O
:	O
</s>
<s>
"	O
Diagnostic	B-Application
ultrasound	I-Application
is	O
recognized	O
as	O
a	O
safe	O
,	O
effective	O
,	O
and	O
highly	O
flexible	O
imaging	B-Application
modality	O
capable	O
of	O
providing	O
clinically	O
relevant	O
information	O
about	O
most	O
parts	O
of	O
the	O
body	O
in	O
a	O
rapid	O
and	O
cost-effective	O
fashion	O
"	O
.	O
</s>
<s>
Diagnostic	B-Application
ultrasound	I-Application
studies	O
of	O
the	O
fetus	O
are	O
generally	O
considered	O
to	O
be	O
safe	O
during	O
pregnancy	O
.	O
</s>
<s>
Although	O
there	O
is	O
no	O
evidence	O
that	O
ultrasound	B-Application
could	O
be	O
harmful	O
to	O
the	O
fetus	O
,	O
medical	O
authorities	O
typically	O
strongly	O
discourage	O
the	O
promotion	O
,	O
selling	O
,	O
or	O
leasing	O
of	O
ultrasound	B-Application
equipment	O
for	O
making	O
"	O
keepsake	O
fetal	O
videos	O
"	O
.	O
</s>
<s>
A	O
study	O
at	O
the	O
Yale	O
School	O
of	O
Medicine	O
published	O
in	O
2006	O
found	O
a	O
small	O
but	O
significant	O
correlation	O
between	O
prolonged	O
and	O
frequent	O
use	O
of	O
ultrasound	B-Application
and	O
abnormal	O
neuronal	O
migration	O
in	O
mice	O
.	O
</s>
<s>
A	O
study	O
performed	O
in	O
Sweden	O
in	O
2001	O
has	O
shown	O
that	O
subtle	O
effects	O
of	O
neurological	O
damage	O
linked	O
to	O
ultrasound	B-Application
were	O
implicated	O
by	O
an	O
increased	O
incidence	O
in	O
left-handedness	O
in	O
boys	O
(	O
a	O
marker	O
for	O
brain	O
problems	O
when	O
not	O
hereditary	O
)	O
and	O
speech	O
delays	O
.	O
</s>
<s>
Diagnostic	O
and	O
therapeutic	B-Algorithm
ultrasound	I-Algorithm
equipment	O
is	O
regulated	O
in	O
the	O
US	O
by	O
the	O
Food	O
and	O
Drug	O
Administration	O
,	O
and	O
worldwide	O
by	O
other	O
national	O
regulatory	O
agencies	O
.	O
</s>
<s>
Certification	O
examinations	O
for	O
sonographers	O
are	O
available	O
in	O
the	O
US	O
from	O
three	O
organizations	O
:	O
the	O
American	O
Registry	O
for	O
Diagnostic	O
Medical	B-Application
Sonography	I-Application
,	O
Cardiovascular	O
Credentialing	O
International	O
and	O
the	O
American	O
Registry	O
of	O
Radiologic	O
Technologists	O
.	O
</s>
<s>
The	O
FDA	O
requires	O
that	O
the	O
machine	O
not	O
exceed	O
established	O
limits	O
,	O
which	O
are	O
reasonably	O
conservative	O
in	O
an	O
effort	O
to	O
maintain	O
diagnostic	B-Application
ultrasound	I-Application
as	O
a	O
safe	O
imaging	B-Application
modality	O
.	O
</s>
<s>
Ultrasound-based	O
pre-natal	O
care	O
and	O
sex	O
screening	O
technologies	O
were	O
launched	O
in	O
India	O
in	O
the	O
1980s	O
.	O
</s>
<s>
With	O
concerns	O
about	O
its	O
misuse	O
for	O
sex-selective	O
abortion	O
,	O
the	O
Government	O
of	O
India	O
passed	O
the	O
Pre-natal	O
Diagnostic	O
Techniques	O
Act	O
(	O
PNDT	O
)	O
in	O
1994	O
to	O
distinguish	O
and	O
regulate	O
legal	O
and	O
illegal	O
uses	O
of	O
ultrasound	B-Application
equipment	O
.	O
</s>
<s>
It	O
is	O
currently	O
illegal	O
and	O
a	O
punishable	O
crime	O
in	O
India	O
to	O
determine	O
or	O
disclose	O
the	O
sex	O
of	O
a	O
fetus	O
using	O
ultrasound	B-Application
equipment	O
.	O
</s>
<s>
In	O
1940	O
,	O
the	O
American	O
acoustical	O
physicist	O
Floyd	O
Firestone	O
devised	O
the	O
first	O
ultrasonic	O
echo	B-Protocol
imaging	B-Application
device	O
,	O
the	O
Supersonic	O
Reflectoscope	O
,	O
to	O
detect	O
internal	O
flaws	O
in	O
metal	O
castings	O
.	O
</s>
<s>
English-born	O
physicist	O
John	O
Wild	O
(	O
1914	O
–	O
2009	O
)	O
first	O
used	O
ultrasound	B-Application
to	O
assess	O
the	O
thickness	O
of	O
bowel	O
tissue	O
as	O
early	O
as	O
1949	O
;	O
he	O
has	O
been	O
described	O
as	O
the	O
"	O
father	O
of	O
medical	B-Application
ultrasound	I-Application
"	O
.	O
</s>
<s>
In	O
1963	O
Meyerdirk	O
&	O
Wright	O
launched	O
production	O
of	O
the	O
first	O
commercial	O
,	O
hand-held	O
,	O
articulated	O
arm	O
,	O
compound	O
contact	O
B-mode	O
scanner	O
,	O
which	O
made	O
ultrasound	B-Application
generally	O
available	O
for	O
medical	O
use	O
.	O
</s>
<s>
He	O
adapted	O
their	O
industrial	O
ultrasound	B-Application
equipment	O
to	O
conduct	O
experiments	O
on	O
various	O
morbid	O
anatomical	O
specimens	O
and	O
assess	O
their	O
ultrasonic	O
characteristics	O
.	O
</s>
<s>
These	O
findings	O
were	O
reported	O
in	O
The	O
Lancet	O
on	O
7	O
June	O
1958	O
as	O
"	O
Investigation	O
of	O
Abdominal	B-Algorithm
Masses	O
by	O
Pulsed	O
Ultrasound	B-Application
"	O
–	O
possibly	O
one	O
of	O
the	O
most	O
important	O
papers	O
published	O
in	O
the	O
field	O
of	O
diagnostic	O
medical	B-Application
imaging	I-Application
.	O
</s>
<s>
Stuart	O
Campbell	O
's	O
pioneering	O
work	O
on	O
fetal	O
cephalometry	B-Algorithm
led	O
to	O
it	O
acquiring	O
long-term	O
status	O
as	O
the	O
definitive	O
method	O
of	O
study	O
of	O
foetal	O
growth	O
.	O
</s>
<s>
Diagnostic	B-Application
ultrasound	I-Application
has	O
since	O
been	O
imported	O
into	O
practically	O
every	O
other	O
area	O
of	O
medicine	O
.	O
</s>
<s>
Medical	B-Application
ultrasonography	I-Application
was	O
used	O
in	O
1953	O
at	O
Lund	O
University	O
by	O
cardiologist	O
Inge	O
Edler	O
and	O
Gustav	O
Ludwig	O
Hertz	O
's	O
son	O
Carl	O
Hellmuth	O
Hertz	O
,	O
who	O
was	O
then	O
a	O
graduate	O
student	O
at	O
the	O
university	O
's	O
department	O
of	O
nuclear	O
physics	O
.	O
</s>
<s>
Edler	O
had	O
asked	O
Hertz	O
if	O
it	O
was	O
possible	O
to	O
use	O
radar	B-Application
to	O
look	O
into	O
the	O
body	O
,	O
but	O
Hertz	O
said	O
this	O
was	O
impossible	O
.	O
</s>
<s>
On	O
December	O
16	O
the	O
same	O
year	O
,	O
the	O
method	O
was	O
applied	O
to	O
generate	O
an	O
echo-encephalogram	O
(	O
ultrasonic	B-Algorithm
probe	I-Algorithm
of	O
the	O
brain	O
)	O
.	O
</s>
<s>
This	O
was	O
the	O
start	O
of	O
the	O
most	O
popular	O
design	O
in	O
the	O
history	O
of	O
ultrasound	B-Application
scanners	I-Application
.	O
</s>
<s>
In	O
the	O
late	O
1960s	O
Gene	O
Strandness	O
and	O
the	O
bio-engineering	O
group	O
at	O
the	O
University	O
of	O
Washington	O
conducted	O
research	O
on	O
Doppler	B-Algorithm
ultrasound	I-Algorithm
as	O
a	O
diagnostic	O
tool	O
for	O
vascular	O
disease	O
.	O
</s>
<s>
Eventually	O
,	O
they	O
developed	O
technologies	O
to	O
use	O
duplex	O
imaging	B-Application
,	O
or	O
Doppler	O
in	O
conjunction	O
with	O
B-mode	O
scanning	O
,	O
to	O
view	O
vascular	O
structures	O
in	O
real	O
time	O
while	O
also	O
providing	O
hemodynamic	O
information	O
.	O
</s>
<s>
The	O
first	O
demonstration	O
of	O
color	B-Algorithm
Doppler	I-Algorithm
was	O
by	O
Geoff	O
Stevenson	O
,	O
who	O
was	O
involved	O
in	O
the	O
early	O
developments	O
and	O
medical	O
use	O
of	O
Doppler	O
shifted	O
ultrasonic	O
energy	O
.	O
</s>
<s>
Major	O
manufacturers	O
of	O
Medical	B-Application
Ultrasound	I-Application
Devices	O
and	O
Equipment	O
are	O
:	O
</s>
