<s>
Measurement	O
and	O
recording	O
techniques	O
that	O
are	O
not	O
primarily	O
designed	O
to	O
produce	O
images	O
,	O
such	O
as	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
,	O
magnetoencephalography	B-Algorithm
(	O
MEG	O
)	O
,	O
electrocardiography	B-Application
(	O
ECG	B-Application
)	O
,	O
and	O
others	O
,	O
represent	O
other	O
technologies	O
that	O
produce	O
data	O
susceptible	O
to	O
representation	O
as	O
a	O
parameter	O
graph	O
versus	O
time	O
or	O
maps	O
that	O
contain	O
data	O
about	O
the	O
measurement	O
locations	O
.	O
</s>
<s>
Medical	O
imaging	O
equipment	O
is	O
manufactured	O
using	O
technology	O
from	O
the	O
semiconductor	O
industry	O
,	O
including	O
CMOS	B-Device
integrated	O
circuit	O
chips	O
,	O
power	O
semiconductor	O
devices	O
,	O
sensors	B-Application
such	O
as	O
image	B-Algorithm
sensors	I-Algorithm
(	O
particularly	O
CMOS	B-Architecture
sensors	I-Architecture
)	O
and	O
biosensors	O
,	O
and	O
processors	O
such	O
as	O
microcontrollers	B-Architecture
,	O
microprocessors	B-Architecture
,	O
digital	B-Architecture
signal	I-Architecture
processors	I-Architecture
,	O
media	B-General_Concept
processors	I-General_Concept
and	O
system-on-chip	B-Architecture
devices	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
medical	B-Application
ultrasound	I-Application
,	O
the	O
probe	O
consists	O
of	O
ultrasonic	O
pressure	O
waves	O
and	O
echoes	O
that	O
go	O
inside	O
the	O
tissue	O
to	O
show	O
the	O
internal	O
structure	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
projectional	O
radiography	O
,	O
the	O
probe	O
uses	O
X-ray	B-Library
radiation	O
,	O
which	O
is	O
absorbed	O
at	O
different	O
rates	O
by	O
different	O
tissue	O
types	O
such	O
as	O
bone	O
,	O
muscle	O
,	O
and	O
fat	O
.	O
</s>
<s>
As	O
a	O
field	O
of	O
scientific	O
investigation	O
,	O
medical	O
imaging	O
constitutes	O
a	O
sub-discipline	O
of	O
biomedical	O
engineering	O
,	O
medical	O
physics	O
or	O
medicine	O
depending	O
on	O
the	O
context	O
:	O
Research	O
and	O
development	O
in	O
the	O
area	O
of	O
instrumentation	O
,	O
image	O
acquisition	O
(	O
e.g.	O
,	O
radiography	O
)	O
,	O
modeling	O
and	O
quantification	O
are	O
usually	O
the	O
preserve	O
of	O
biomedical	O
engineering	O
,	O
medical	O
physics	O
,	O
and	O
computer	B-General_Concept
science	I-General_Concept
;	O
Research	O
into	O
the	O
application	O
and	O
interpretation	O
of	O
medical	O
images	O
is	O
usually	O
the	O
preserve	O
of	O
radiology	O
and	O
the	O
medical	O
sub-discipline	O
relevant	O
to	O
medical	O
condition	O
or	O
area	O
of	O
medical	O
science	O
(	O
neuroscience	O
,	O
cardiology	O
,	O
psychiatry	O
,	O
psychology	O
,	O
etc	O
.	O
)	O
</s>
<s>
These	O
2D	O
techniques	O
are	O
still	O
in	O
wide	O
use	O
despite	O
the	O
advance	O
of	O
3D	O
tomography	B-Algorithm
due	O
to	O
the	O
low	O
cost	O
,	O
high	O
resolution	O
,	O
and	O
depending	O
on	O
the	O
application	O
,	O
lower	O
radiation	O
dosages	O
with	O
2D	O
technique	O
.	O
</s>
<s>
Fluoroscopy	O
produces	O
real-time	O
images	O
of	O
internal	O
structures	O
of	O
the	O
body	O
in	O
a	O
similar	O
fashion	O
to	O
radiography	O
,	O
but	O
employs	O
a	O
constant	O
input	O
of	O
x-rays	B-Library
,	O
at	O
a	O
lower	O
dose	O
rate	O
.	O
</s>
<s>
Contrast	B-Algorithm
media	I-Algorithm
,	O
such	O
as	O
barium	O
,	O
iodine	O
,	O
and	O
air	O
are	O
used	O
to	O
visualize	O
internal	O
organs	O
as	O
they	O
work	O
.	O
</s>
<s>
Projectional	O
radiographs	O
,	O
more	O
commonly	O
known	O
as	O
x-rays	B-Library
,	O
are	O
often	O
used	O
to	O
determine	O
the	O
type	O
and	O
extent	O
of	O
a	O
fracture	B-Application
as	O
well	O
as	O
for	O
detecting	O
pathological	O
changes	O
in	O
the	O
lungs	O
.	O
</s>
<s>
With	O
the	O
use	O
of	O
radio-opaque	O
contrast	B-Algorithm
media	I-Algorithm
,	O
such	O
as	O
barium	O
,	O
they	O
can	O
also	O
be	O
used	O
to	O
visualize	O
the	O
structure	O
of	O
the	O
stomach	O
and	O
intestines	O
–	O
this	O
can	O
help	O
diagnose	O
ulcers	O
or	O
certain	O
types	O
of	O
colon	O
cancer	O
.	O
</s>
<s>
A	O
magnetic	O
resonance	O
imaging	O
instrument	O
(	O
MRI	B-Algorithm
scanner	O
)	O
,	O
or	O
"	O
nuclear	O
magnetic	O
resonance	O
(	O
NMR	O
)	O
imaging	O
"	O
scanner	O
as	O
it	O
was	O
originally	O
known	O
,	O
uses	O
powerful	O
magnets	O
to	O
polarize	O
and	O
excite	O
hydrogen	O
nuclei	O
(	O
i.e.	O
,	O
single	O
protons	B-Application
)	O
of	O
water	O
molecules	O
in	O
human	O
tissue	O
,	O
producing	O
a	O
detectable	O
signal	O
which	O
is	O
spatially	O
encoded	O
,	O
resulting	O
in	O
images	O
of	O
the	O
body	O
.	O
</s>
<s>
The	O
MRI	B-Algorithm
machine	O
emits	O
a	O
radio	O
frequency	O
(	O
RF	O
)	O
pulse	O
at	O
the	O
resonant	O
frequency	O
of	O
the	O
hydrogen	O
atoms	O
on	O
water	O
molecules	O
.	O
</s>
<s>
The	O
RF	O
pulse	O
is	O
absorbed	O
by	O
protons	B-Application
,	O
causing	O
their	O
direction	O
with	O
respect	O
to	O
the	O
primary	O
magnetic	O
field	O
to	O
change	O
.	O
</s>
<s>
When	O
the	O
RF	O
pulse	O
is	O
turned	O
off	O
,	O
the	O
protons	B-Application
"	O
relax	O
"	O
back	O
to	O
alignment	O
with	O
the	O
primary	O
magnet	O
and	O
emit	O
radio-waves	O
in	O
the	O
process	O
.	O
</s>
<s>
The	O
resonant	O
frequency	O
of	O
a	O
spinning	O
magnetic	O
dipole	O
(	O
of	O
which	O
protons	B-Application
are	O
one	O
example	O
)	O
is	O
called	O
the	O
Larmor	O
frequency	O
and	O
is	O
determined	O
by	O
the	O
strength	O
of	O
the	O
main	O
magnetic	O
field	O
and	O
the	O
chemical	O
environment	O
of	O
the	O
nuclei	O
of	O
interest	O
.	O
</s>
<s>
MRI	B-Algorithm
uses	O
three	O
electromagnetic	O
fields	O
:	O
a	O
very	O
strong	O
(	O
typically	O
1.5	O
to	O
3	O
teslas	O
)	O
static	O
magnetic	O
field	O
to	O
polarize	O
the	O
hydrogen	O
nuclei	O
,	O
called	O
the	O
primary	O
field	O
;	O
gradient	O
fields	O
that	O
can	O
be	O
modified	O
to	O
vary	O
in	O
space	O
and	O
time	O
(	O
on	O
the	O
order	O
of	O
1kHz	O
)	O
for	O
spatial	O
encoding	O
,	O
often	O
simply	O
called	O
gradients	O
;	O
and	O
a	O
spatially	O
homogeneous	O
radio-frequency	O
(	O
RF	O
)	O
field	O
for	O
manipulation	O
of	O
the	O
hydrogen	O
nuclei	O
to	O
produce	O
measurable	O
signals	O
,	O
collected	O
through	O
an	O
RF	O
antenna	O
.	O
</s>
<s>
Like	O
CT	O
,	O
MRI	B-Algorithm
traditionally	O
creates	O
a	O
two-dimensional	O
image	O
of	O
a	O
thin	O
"	O
slice	O
"	O
of	O
the	O
body	O
and	O
is	O
therefore	O
considered	O
a	O
tomographic	B-Algorithm
imaging	I-Algorithm
technique	O
.	O
</s>
<s>
Modern	O
MRI	B-Algorithm
instruments	O
are	O
capable	O
of	O
producing	O
images	O
in	O
the	O
form	O
of	O
3D	O
blocks	O
,	O
which	O
may	O
be	O
considered	O
a	O
generalization	O
of	O
the	O
single-slice	O
,	O
tomographic	B-Algorithm
,	O
concept	O
.	O
</s>
<s>
Unlike	O
CT	O
,	O
MRI	B-Algorithm
does	O
not	O
involve	O
the	O
use	O
of	O
ionizing	O
radiation	O
and	O
is	O
therefore	O
not	O
associated	O
with	O
the	O
same	O
health	O
hazards	O
.	O
</s>
<s>
For	O
example	O
,	O
because	O
MRI	B-Algorithm
has	O
only	O
been	O
in	O
use	O
since	O
the	O
early	O
1980s	O
,	O
there	O
are	O
no	O
known	O
long-term	O
effects	O
of	O
exposure	O
to	O
strong	O
static	O
fields	O
(	O
this	O
is	O
the	O
subject	O
of	O
some	O
debate	O
;	O
see	O
'	O
Safety	O
 '	O
in	O
MRI	B-Algorithm
)	O
and	O
therefore	O
there	O
is	O
no	O
limit	O
to	O
the	O
number	O
of	O
scans	O
to	O
which	O
an	O
individual	O
can	O
be	O
subjected	O
,	O
in	O
contrast	O
with	O
X-ray	B-Library
and	O
CT	O
.	O
</s>
<s>
Because	O
CT	O
and	O
MRI	B-Algorithm
are	O
sensitive	O
to	O
different	O
tissue	O
properties	O
,	O
the	O
appearances	O
of	O
the	O
images	O
obtained	O
with	O
the	O
two	O
techniques	O
differ	O
markedly	O
.	O
</s>
<s>
In	O
CT	O
,	O
X-rays	B-Library
must	O
be	O
blocked	O
by	O
some	O
form	O
of	O
dense	O
tissue	O
to	O
create	O
an	O
image	O
,	O
so	O
the	O
image	O
quality	O
when	O
looking	O
at	O
soft	O
tissues	O
will	O
be	O
poor	O
.	O
</s>
<s>
In	O
MRI	B-Algorithm
,	O
while	O
any	O
nucleus	O
with	O
a	O
net	O
nuclear	O
spin	O
can	O
be	O
used	O
,	O
the	O
proton	B-Application
of	O
the	O
hydrogen	O
atom	O
remains	O
the	O
most	O
widely	O
used	O
,	O
especially	O
in	O
the	O
clinical	O
setting	O
,	O
because	O
it	O
is	O
so	O
ubiquitous	O
and	O
returns	O
a	O
large	O
signal	O
.	O
</s>
<s>
This	O
nucleus	O
,	O
present	O
in	O
water	O
molecules	O
,	O
allows	O
the	O
excellent	O
soft-tissue	O
contrast	O
achievable	O
with	O
MRI	B-Algorithm
.	O
</s>
<s>
A	O
number	O
of	O
different	O
pulse	O
sequences	O
can	O
be	O
used	O
for	O
specific	O
MRI	B-Algorithm
diagnostic	O
imaging	O
(	O
multiparametric	O
MRI	B-Algorithm
or	O
mpMRI	O
)	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
differentiate	O
tissue	O
characteristics	O
by	O
combining	O
two	O
or	O
more	O
of	O
the	O
following	O
imaging	O
sequences	O
,	O
depending	O
on	O
the	O
information	O
being	O
sought	O
:	O
T1-weighted	O
(	O
T1-MRI	O
)	O
,	O
T2-weighted	O
(	O
T2-MRI	O
)	O
,	O
diffusion	O
weighted	O
imaging	O
(	O
DWI-MRI	O
)	O
,	O
dynamic	O
contrast	B-Algorithm
enhancement	I-Algorithm
(	O
DCE-MRI	O
)	O
,	O
and	O
spectroscopy	O
(	O
MRI-S	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
imaging	O
of	O
prostate	O
tumors	O
is	O
better	O
accomplished	O
using	O
T2-MRI	O
and	O
DWI-MRI	O
than	O
T2-weighted	O
imaging	O
alone	O
.	O
</s>
<s>
Gamma	O
cameras	O
and	O
PET	B-Application
scanners	I-Application
are	O
used	O
in	O
e.g.	O
</s>
<s>
scintigraphy	O
,	O
SPECT	O
and	O
PET	B-Application
to	O
detect	O
regions	O
of	O
biologic	O
activity	O
that	O
may	O
be	O
associated	O
with	O
a	O
disease	O
.	O
</s>
<s>
Isotopes	O
are	O
often	O
preferentially	O
absorbed	O
by	O
biologically	O
active	O
tissue	O
in	O
the	O
body	O
,	O
and	O
can	O
be	O
used	O
to	O
identify	O
tumors	O
or	O
fracture	B-Application
points	O
in	O
bone	O
.	O
</s>
<s>
SPECT	O
is	O
a	O
3D	O
tomographic	B-Algorithm
technique	O
that	O
uses	O
gamma	O
camera	O
data	O
from	O
many	O
projections	O
and	O
can	O
be	O
reconstructed	O
in	O
different	O
planes	O
.	O
</s>
<s>
A	O
dual	O
detector	B-Application
head	O
gamma	O
camera	O
combined	O
with	O
a	O
CT	O
scanner	O
,	O
which	O
provides	O
localization	O
of	O
functional	O
SPECT	O
data	O
,	O
is	O
termed	O
a	O
SPECT-CT	O
camera	O
,	O
and	O
has	O
shown	O
utility	O
in	O
advancing	O
the	O
field	O
of	O
molecular	O
imaging	O
.	O
</s>
<s>
In	O
most	O
other	O
medical	O
imaging	O
modalities	O
,	O
energy	O
is	O
passed	O
through	O
the	O
body	O
and	O
the	O
reaction	O
or	O
result	O
is	O
read	O
by	O
detectors	B-Application
.	O
</s>
<s>
The	O
emissions	O
of	O
the	O
gamma	O
rays	O
are	O
captured	O
by	O
detectors	B-Application
that	O
surround	O
the	O
body	O
.	O
</s>
<s>
This	O
essentially	O
means	O
that	O
the	O
human	O
is	O
now	O
the	O
source	O
of	O
the	O
radioactivity	O
,	O
rather	O
than	O
the	O
medical	O
imaging	O
devices	O
such	O
as	O
X-ray	B-Library
or	O
CT	O
.	O
</s>
<s>
Positron	B-Application
emission	I-Application
tomography	I-Application
(	O
PET	B-Application
)	O
uses	O
coincidence	O
detection	O
to	O
image	O
functional	O
processes	O
.	O
</s>
<s>
PET	B-Application
images	O
can	O
be	O
viewed	O
in	O
comparison	O
to	O
computed	O
tomography	B-Algorithm
scans	O
to	O
determine	O
an	O
anatomic	O
correlate	O
.	O
</s>
<s>
Modern	O
scanners	O
may	O
integrate	O
PET	B-Application
,	O
allowing	O
PET-CT	O
,	O
or	O
PET-MRI	B-Algorithm
to	O
optimize	O
the	O
image	O
reconstruction	O
involved	O
with	O
positron	O
imaging	O
.	O
</s>
<s>
By	O
this	O
method	O
,	O
functional	O
information	O
from	O
SPECT	O
or	O
positron	B-Application
emission	I-Application
tomography	I-Application
can	O
be	O
related	O
to	O
anatomical	O
information	O
provided	O
by	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	B-Algorithm
)	O
.	O
</s>
<s>
Similarly	O
,	O
fiducial	O
points	O
established	O
during	O
MRI	B-Algorithm
can	O
be	O
correlated	O
with	O
brain	O
images	O
generated	O
by	O
magnetoencephalography	B-Algorithm
to	O
localize	O
the	O
source	O
of	O
brain	B-Application
activity	I-Application
.	O
</s>
<s>
Medical	B-Application
ultrasound	I-Application
uses	O
high	O
frequency	O
broadband	B-General_Concept
sound	O
waves	O
in	O
the	O
megahertz	O
range	O
that	O
are	O
reflected	O
by	O
tissue	O
to	O
varying	O
degrees	O
to	O
produce	O
(	O
up	O
to	O
3D	O
)	O
images	O
.	O
</s>
<s>
Uses	O
of	O
ultrasound	B-Application
are	O
much	O
broader	O
,	O
however	O
.	O
</s>
<s>
While	O
it	O
may	O
provide	O
less	O
anatomical	O
detail	O
than	O
techniques	O
such	O
as	O
CT	O
or	O
MRI	B-Algorithm
,	O
it	O
has	O
several	O
advantages	O
which	O
make	O
it	O
ideal	O
in	O
numerous	O
situations	O
,	O
in	O
particular	O
that	O
it	O
studies	O
the	O
function	O
of	O
moving	O
structures	O
in	O
real-time	O
,	O
emits	O
no	O
ionizing	O
radiation	O
,	O
and	O
contains	O
speckle	B-Algorithm
that	O
can	O
be	O
used	O
in	O
elastography	B-Algorithm
.	O
</s>
<s>
Ultrasound	B-Application
is	O
also	O
used	O
as	O
a	O
popular	O
research	O
tool	O
for	O
capturing	O
raw	O
data	O
,	O
that	O
can	O
be	O
made	O
available	O
through	O
an	O
ultrasound	B-Application
research	O
interface	O
,	O
for	O
the	O
purpose	O
of	O
tissue	O
characterization	O
and	O
implementation	O
of	O
new	O
image	O
processing	O
techniques	O
.	O
</s>
<s>
The	O
concepts	O
of	O
ultrasound	B-Application
differ	O
from	O
other	O
medical	O
imaging	O
modalities	O
in	O
the	O
fact	O
that	O
it	O
is	O
operated	O
by	O
the	O
transmission	O
and	O
receipt	O
of	O
sound	O
waves	O
.	O
</s>
<s>
A	O
path	O
of	O
reflected	O
sound	O
waves	O
in	O
a	O
multilayered	O
structure	O
can	O
be	O
defined	O
by	O
an	O
input	O
acoustic	O
impedance	O
(	O
ultrasound	B-Application
sound	O
wave	O
)	O
and	O
the	O
Reflection	O
and	O
transmission	O
coefficients	O
of	O
the	O
relative	O
structures	O
.	O
</s>
<s>
Ultrasound	B-Application
scanners	I-Application
can	O
be	O
taken	O
to	O
critically	O
ill	O
patients	O
in	O
intensive	O
care	O
units	O
,	O
avoiding	O
the	O
danger	O
caused	O
while	O
moving	O
the	O
patient	O
to	O
the	O
radiology	O
department	O
.	O
</s>
<s>
Elastography	B-Algorithm
is	O
a	O
relatively	O
new	O
imaging	O
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
,	O
as	O
elasticity	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
several	O
elastographic	O
techniques	O
based	O
on	O
the	O
use	O
of	O
ultrasound	B-Application
,	O
magnetic	O
resonance	O
imaging	O
and	O
tactile	B-Algorithm
imaging	I-Algorithm
.	O
</s>
<s>
The	O
wide	O
clinical	O
use	O
of	O
ultrasound	B-Algorithm
elastography	I-Algorithm
is	O
a	O
result	O
of	O
the	O
implementation	O
of	O
technology	O
in	O
clinical	O
ultrasound	B-Application
machines	I-Application
.	O
</s>
<s>
Main	O
branches	O
of	O
ultrasound	B-Algorithm
elastography	I-Algorithm
include	O
Quasistatic	O
Elastography/Strain	O
Imaging	O
,	O
Shear	O
Wave	O
Elasticity	O
Imaging	O
(	O
SWEI	O
)	O
,	O
Acoustic	O
Radiation	O
Force	O
Impulse	O
imaging	O
(	O
ARFI	O
)	O
,	O
Supersonic	O
Shear	O
Imaging	O
(	O
SSI	O
)	O
,	O
and	O
Transient	O
Elastography	B-Algorithm
.	O
</s>
<s>
In	O
the	O
last	O
decade	O
a	O
steady	O
increase	O
of	O
activities	O
in	O
the	O
field	O
of	O
elastography	B-Algorithm
is	O
observed	O
demonstrating	O
successful	O
application	O
of	O
the	O
technology	O
in	O
various	O
areas	O
of	O
medical	O
diagnostics	O
and	O
treatment	O
monitoring	O
.	O
</s>
<s>
Photoacoustic	B-Algorithm
imaging	I-Algorithm
is	O
a	O
recently	O
developed	O
hybrid	O
biomedical	O
imaging	O
modality	O
based	O
on	O
the	O
photoacoustic	O
effect	O
.	O
</s>
<s>
Recent	O
studies	O
have	O
shown	O
that	O
photoacoustic	B-Algorithm
imaging	I-Algorithm
can	O
be	O
used	O
in	O
vivo	O
for	O
tumor	O
angiogenesis	O
monitoring	O
,	O
blood	O
oxygenation	O
mapping	O
,	O
functional	O
brain	B-Algorithm
imaging	I-Algorithm
,	O
and	O
skin	O
melanoma	O
detection	O
,	O
etc	O
.	O
</s>
<s>
Tomography	B-Algorithm
is	O
the	O
imaging	O
by	O
sections	O
or	O
sectioning	O
.	O
</s>
<s>
X-ray	B-Library
computed	O
tomography	B-Algorithm
(	O
CT	O
)	O
,	O
or	O
Computed	O
Axial	O
Tomography	B-Algorithm
(	O
CAT	O
)	O
scan	O
,	O
is	O
a	O
helical	O
tomography	B-Algorithm
technique	O
(	O
latest	O
generation	O
)	O
,	O
which	O
traditionally	O
produces	O
a	O
2D	O
image	O
of	O
the	O
structures	O
in	O
a	O
thin	O
section	O
of	O
the	O
body	O
.	O
</s>
<s>
In	O
CT	O
,	O
a	O
beam	O
of	O
X-rays	B-Library
spins	O
around	O
an	O
object	O
being	O
examined	O
and	O
is	O
picked	O
up	O
by	O
sensitive	O
radiation	O
detectors	B-Application
after	O
having	O
penetrated	O
the	O
object	O
from	O
multiple	O
angles	O
.	O
</s>
<s>
A	O
computer	O
then	O
analyses	O
the	O
information	O
received	O
from	O
the	O
scanner	O
's	O
detectors	B-Application
and	O
constructs	O
a	O
detailed	O
image	O
of	O
the	O
object	O
and	O
its	O
contents	O
using	O
the	O
mathematical	O
principles	O
laid	O
out	O
in	O
the	O
Radon	B-Algorithm
transform	I-Algorithm
.	O
</s>
<s>
CT	O
is	O
based	O
on	O
the	O
same	O
principles	O
as	O
X-Ray	B-Library
projections	O
but	O
in	O
this	O
case	O
,	O
the	O
patient	O
is	O
enclosed	O
in	O
a	O
surrounding	O
ring	O
of	O
detectors	B-Application
assigned	O
with	O
500	O
–	O
1000	O
scintillation	O
detectors	B-Application
(	O
fourth-generation	O
X-Ray	B-Library
CT	O
scanner	O
geometry	O
)	O
.	O
</s>
<s>
Previously	O
in	O
older	O
generation	O
scanners	O
,	O
the	O
X-Ray	B-Library
beam	O
was	O
paired	O
by	O
a	O
translating	O
source	O
and	O
detector	B-Application
.	O
</s>
<s>
Computed	O
tomography	B-Algorithm
has	O
almost	O
completely	O
replaced	O
focal	B-Algorithm
plane	I-Algorithm
tomography	I-Algorithm
in	O
X-ray	B-Library
tomography	B-Algorithm
imaging	O
.	O
</s>
<s>
Positron	B-Application
emission	I-Application
tomography	I-Application
(	O
PET	B-Application
)	O
also	O
used	O
in	O
conjunction	O
with	O
computed	O
tomography	B-Algorithm
,	O
PET-CT	O
,	O
and	O
magnetic	O
resonance	O
imaging	O
PET-MRI	B-Algorithm
.	O
</s>
<s>
Magnetic	O
resonance	O
imaging	O
(	O
MRI	B-Algorithm
)	O
commonly	O
produces	O
tomographic	B-Algorithm
images	O
of	O
cross-sections	O
of	O
the	O
body	O
.	O
</s>
<s>
(	O
See	O
separate	O
MRI	B-Algorithm
section	O
in	O
this	O
article	O
.	O
)	O
</s>
<s>
When	O
ultrasound	B-Application
is	O
used	O
to	O
image	O
the	O
heart	O
it	O
is	O
referred	O
to	O
as	O
an	O
echocardiogram	B-Application
.	O
</s>
<s>
Echocardiography	B-Application
allows	O
detailed	O
structures	O
of	O
the	O
heart	O
,	O
including	O
chamber	O
size	O
,	O
heart	O
function	O
,	O
the	O
valves	O
of	O
the	O
heart	O
,	O
as	O
well	O
as	O
the	O
pericardium	O
(	O
the	O
sac	O
around	O
the	O
heart	O
)	O
to	O
be	O
seen	O
.	O
</s>
<s>
Echocardiography	B-Application
uses	O
2D	O
,	O
3D	O
,	O
and	O
Doppler	O
imaging	O
to	O
create	O
pictures	O
of	O
the	O
heart	O
and	O
visualize	O
the	O
blood	O
flowing	O
through	O
each	O
of	O
the	O
four	O
heart	O
valves	O
.	O
</s>
<s>
Echocardiography	B-Application
is	O
widely	O
used	O
in	O
an	O
array	O
of	O
patients	O
ranging	O
from	O
those	O
experiencing	O
symptoms	O
,	O
such	O
as	O
shortness	O
of	O
breath	O
or	O
chest	O
pain	O
,	O
to	O
those	O
undergoing	O
cancer	O
treatments	O
.	O
</s>
<s>
Transthoracic	O
ultrasound	B-Application
has	O
been	O
proven	O
to	O
be	O
safe	O
for	O
patients	O
of	O
all	O
ages	O
,	O
from	O
infants	O
to	O
the	O
elderly	O
,	O
without	O
risk	O
of	O
harmful	O
side	O
effects	O
or	O
radiation	O
,	O
differentiating	O
it	O
from	O
other	O
imaging	O
modalities	O
.	O
</s>
<s>
Echocardiography	B-Application
is	O
one	O
of	O
the	O
most	O
commonly	O
used	O
imaging	O
modalities	O
in	O
the	O
world	O
due	O
to	O
its	O
portability	O
and	O
use	O
in	O
a	O
variety	O
of	O
applications	O
.	O
</s>
<s>
In	O
emergency	O
situations	O
,	O
echocardiography	B-Application
is	O
quick	O
,	O
easily	O
accessible	O
,	O
and	O
able	O
to	O
be	O
performed	O
at	O
the	O
bedside	O
,	O
making	O
it	O
the	O
modality	O
of	O
choice	O
for	O
many	O
physicians	O
.	O
</s>
<s>
NIRS	O
(	O
near	O
infrared	O
spectroscopy	O
)	O
is	O
used	O
for	O
the	O
purpose	O
of	O
functional	B-Algorithm
neuroimaging	I-Algorithm
and	O
has	O
been	O
widely	O
accepted	O
as	O
a	O
brain	B-Algorithm
imaging	I-Algorithm
technique	O
.	O
</s>
<s>
Magnetic	O
resonance	O
imaging	O
(	O
MRI	B-Algorithm
)	O
without	O
MRI	B-Algorithm
contrast	I-Algorithm
agents	I-Algorithm
as	O
well	O
as	O
obstetric	O
ultrasonography	O
are	O
not	O
associated	O
with	O
any	O
risk	O
for	O
the	O
mother	O
or	O
the	O
fetus	O
,	O
and	O
are	O
the	O
imaging	O
techniques	O
of	O
choice	O
for	O
pregnant	O
women	O
.	O
</s>
<s>
Volume	O
rendering	O
techniques	O
have	O
been	O
developed	O
to	O
enable	O
CT	O
,	O
MRI	B-Algorithm
and	O
ultrasound	B-Application
scanning	I-Application
software	O
to	O
produce	O
3D	O
images	O
for	O
the	O
physician	O
.	O
</s>
<s>
Traditionally	O
CT	O
and	O
MRI	B-Algorithm
scans	O
produced	O
2D	O
static	O
output	O
on	O
film	O
.	O
</s>
<s>
To	O
produce	O
3D	O
images	O
,	O
many	O
scans	O
are	O
made	O
and	O
then	O
combined	B-Algorithm
by	I-Algorithm
computers	I-Algorithm
to	O
produce	O
a	O
3D	O
model	O
,	O
which	O
can	O
then	O
be	O
manipulated	O
by	O
the	O
physician	O
.	O
</s>
<s>
3D	B-Algorithm
ultrasounds	I-Algorithm
are	O
produced	O
using	O
a	O
somewhat	O
similar	O
technique	O
.	O
</s>
<s>
In	O
diagnosing	O
disease	O
of	O
the	O
viscera	O
of	O
the	O
abdomen	O
,	O
ultrasound	B-Application
is	O
particularly	O
sensitive	O
on	O
imaging	O
of	O
biliary	O
tract	O
,	O
urinary	O
tract	O
and	O
female	O
reproductive	O
organs	O
(	O
ovary	O
,	O
fallopian	O
tubes	O
)	O
.	O
</s>
<s>
Neuroimaging	B-Algorithm
has	O
also	O
been	O
used	O
in	O
experimental	O
circumstances	O
to	O
allow	O
people	O
(	O
especially	O
disabled	O
persons	O
)	O
to	O
control	O
outside	O
devices	O
,	O
acting	O
as	O
a	O
brain	B-Application
computer	I-Application
interface	I-Application
.	O
</s>
<s>
Used	O
primarily	O
in	O
ultrasound	B-Application
imaging	I-Application
,	O
capturing	O
the	O
image	O
produced	O
by	O
a	O
medical	O
imaging	O
device	O
is	O
required	O
for	O
archiving	O
and	O
telemedicine	B-Application
applications	O
.	O
</s>
<s>
In	O
most	O
scenarios	O
,	O
a	O
frame	B-Device
grabber	I-Device
is	O
used	O
in	O
order	O
to	O
capture	O
the	O
video	O
signal	O
from	O
the	O
medical	O
device	O
and	O
relay	O
it	O
to	O
a	O
computer	O
for	O
further	O
processing	O
and	O
operations	O
.	O
</s>
<s>
The	O
Digital	O
Imaging	O
and	O
Communication	O
in	O
Medicine	O
(	O
DICOM	B-Algorithm
)	O
Standard	O
is	O
used	O
globally	O
to	O
store	O
,	O
exchange	O
,	O
and	O
transmit	O
medical	O
images	O
.	O
</s>
<s>
The	O
DICOM	B-Algorithm
Standard	O
incorporates	O
protocols	O
for	O
imaging	O
techniques	O
such	O
as	O
radiography	O
,	O
computed	O
tomography	B-Algorithm
(	O
CT	O
)	O
,	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	B-Algorithm
)	O
,	O
ultrasound	B-Application
,	O
and	O
radiation	O
therapy	O
.	O
</s>
<s>
Medical	O
imaging	O
techniques	O
produce	O
very	O
large	O
amounts	O
of	O
data	O
,	O
especially	O
from	O
CT	O
,	O
MRI	B-Algorithm
and	O
PET	B-Application
modalities	O
.	O
</s>
<s>
JPEG	O
2000	O
image	O
compression	O
is	O
used	O
by	O
the	O
DICOM	B-Algorithm
standard	O
for	O
storage	O
and	O
transmission	O
of	O
medical	O
images	O
.	O
</s>
<s>
The	O
cost	O
and	O
feasibility	O
of	O
accessing	O
large	O
image	O
data	O
sets	O
over	O
low	O
or	O
various	O
bandwidths	O
are	O
further	O
addressed	O
by	O
use	O
of	O
another	O
DICOM	B-Algorithm
standard	O
,	O
called	O
JPIP	O
,	O
to	O
enable	O
efficient	O
streaming	O
of	O
the	O
JPEG	O
2000	O
compressed	O
image	O
data	O
.	O
</s>
<s>
There	O
has	O
been	O
growing	O
trend	O
to	O
migrate	O
from	O
on-premise	O
PACS	B-Application
to	O
a	O
cloud-based	B-Architecture
PACS	B-Application
.	O
</s>
<s>
Cloud	B-Architecture
computing	I-Architecture
offers	O
the	O
imaging	O
department	O
of	O
the	O
future	O
the	O
tools	O
to	O
manage	O
data	O
much	O
more	O
intelligently.	O
"	O
</s>
<s>
Imaging	O
techniques	O
such	O
as	O
positron	B-Application
emission	I-Application
tomography	I-Application
(	O
PET	B-Application
)	O
and	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	B-Algorithm
)	O
are	O
routinely	O
used	O
in	O
oncology	O
and	O
neuroscience	O
areas	O
,	O
.	O
</s>
<s>
In	O
Alzheimer	O
's	O
disease	O
,	O
MRI	B-Algorithm
scans	O
of	O
the	O
entire	O
brain	O
can	O
accurately	O
assess	O
the	O
rate	O
of	O
hippocampal	O
atrophy	O
,	O
while	O
PET	B-Application
scans	I-Application
can	O
measure	O
the	O
brain	O
's	O
metabolic	O
activity	O
by	O
measuring	O
regional	O
glucose	O
metabolism	O
,	O
and	O
beta-amyloid	O
plaques	O
using	O
tracers	O
such	O
as	O
Pittsburgh	O
compound	O
B	O
(	O
PiB	O
)	O
.	O
</s>
<s>
The	O
protocol	O
is	O
an	O
outline	O
that	O
standardizes	O
(	O
as	O
far	O
as	O
practically	O
possible	O
)	O
the	O
way	O
in	O
which	O
the	O
images	O
are	O
acquired	O
using	O
the	O
various	O
modalities	O
(	O
PET	B-Application
,	O
SPECT	O
,	O
CT	O
,	O
MRI	B-Algorithm
)	O
.	O
</s>
<s>
Lead	O
is	O
the	O
main	O
material	O
used	O
for	O
radiographic	O
shielding	O
against	O
scattered	O
X-rays	B-Library
.	O
</s>
<s>
In	O
magnetic	O
resonance	O
imaging	O
,	O
there	O
is	O
MRI	B-Algorithm
RF	O
shielding	O
as	O
well	O
as	O
magnetic	O
shielding	O
to	O
prevent	O
external	O
disturbance	O
of	O
image	O
quality	O
.	O
</s>
<s>
The	O
UK	O
General	O
Medical	O
Council	O
's	O
ethical	O
guidelines	O
indicate	O
that	O
the	O
Council	O
does	O
not	O
require	O
consent	O
prior	O
to	O
secondary	O
uses	O
of	O
X-ray	B-Library
images	O
.	O
</s>
<s>
In	O
2016	O
,	O
the	O
manufacturing	O
industry	O
was	O
characterized	O
as	O
oligopolistic	O
and	O
mature	O
;	O
new	O
entrants	O
included	O
in	O
Samsung	B-Application
and	O
Neusoft	O
Medical	O
.	O
</s>
<s>
Copyright	O
Office	O
Practices	O
,	O
"	O
the	O
Office	O
will	O
not	O
register	O
works	O
produced	O
by	O
a	O
machine	O
or	O
mere	O
mechanical	O
process	O
that	O
operates	O
randomly	O
or	O
automatically	O
without	O
any	O
creative	O
input	O
or	O
intervention	O
from	O
a	O
human	O
author	O
"	O
including	O
"	O
Medical	O
imaging	O
produced	O
by	O
x-rays	B-Library
,	O
ultrasounds	B-Application
,	O
magnetic	O
resonance	O
imaging	O
,	O
or	O
other	O
diagnostic	O
equipment.	O
"	O
</s>
<s>
Yet	O
,	O
there	O
is	O
no	O
U.S.	O
federal	O
case	O
law	O
directly	O
addressing	O
the	O
issue	O
of	O
the	O
copyrightability	O
of	O
x-ray	B-Library
images	O
.	O
</s>
<s>
In	O
Germany	O
,	O
X-ray	B-Library
images	O
as	O
well	O
as	O
MRI	B-Algorithm
,	O
medical	B-Application
ultrasound	I-Application
,	O
PET	B-Application
and	O
scintigraphy	O
images	O
are	O
protected	O
by	O
(	O
copyright-like	O
)	O
related	O
rights	O
or	O
neighbouring	O
rights	O
.	O
</s>
<s>
The	O
literature	O
seems	O
to	O
uniformly	O
consider	O
the	O
medical	O
doctor	O
,	O
dentist	O
or	O
veterinary	O
physician	O
as	O
the	O
rights	O
holder	O
,	O
which	O
may	O
result	O
from	O
the	O
circumstance	O
that	O
in	O
Germany	O
many	O
x-rays	B-Library
are	O
performed	O
in	O
ambulatory	O
settings	O
.	O
</s>
<s>
Medical	O
images	O
created	O
in	O
the	O
United	O
Kingdom	O
will	O
normally	O
be	O
protected	O
by	O
copyright	O
due	O
to	O
"	O
the	O
high	O
level	O
of	O
skill	O
,	O
labour	O
and	O
judgement	O
required	O
to	O
produce	O
a	O
good	O
quality	O
x-ray	B-Library
,	O
particularly	O
to	O
show	O
contrast	O
between	O
bones	O
and	O
various	O
soft	O
tissues	O
"	O
.	O
</s>
<s>
Medical	O
imaging	O
may	O
possibly	O
be	O
included	O
in	O
the	O
scope	O
of	O
"	O
photography	O
"	O
,	O
similarly	O
to	O
a	O
U.S.	O
statement	O
that	O
"	O
MRI	B-Algorithm
images	O
,	O
CT	O
scans	O
,	O
and	O
the	O
like	O
are	O
analogous	O
to	O
photography.	O
"	O
</s>
