<s>
Rotational	B-Algorithm
angiography	I-Algorithm
is	O
a	O
medical	O
imaging	O
technique	O
based	O
on	O
x-ray	B-Library
,	O
that	O
allows	O
to	O
acquire	O
CT-like	O
3D	O
volumes	O
during	O
hybrid	O
surgery	O
or	O
during	O
a	O
catheter	O
intervention	O
using	O
a	O
fixed	O
C-Arm	O
.	O
</s>
<s>
The	O
fixed	O
C-Arm	O
thereby	O
rotates	O
around	O
the	O
patient	O
and	O
acquires	O
a	O
series	O
of	O
x-ray	B-Library
images	O
that	O
are	O
then	O
reconstructed	O
through	O
software	O
algorithms	O
into	O
a	O
3D	O
image	O
.	O
</s>
<s>
Synonyms	O
for	O
rotational	B-Algorithm
angiography	I-Algorithm
include	O
flat-panel	O
volume	B-Algorithm
CT	I-Algorithm
and	O
cone-beam	O
CT	O
.	O
</s>
<s>
In	O
order	O
to	O
acquire	O
a	O
3D	O
image	O
with	O
a	O
fixed	O
C-Arm	O
,	O
the	O
C-Arm	O
is	O
positioned	O
at	O
the	O
body	O
part	O
in	O
question	O
so	O
that	O
this	O
body	O
part	O
is	O
in	O
the	O
isocenter	O
between	O
the	O
x-ray	B-Library
tube	O
and	O
the	O
detector	B-Application
.	O
</s>
<s>
3D	O
angiography	O
or	O
Rotational	B-Algorithm
Angiography	I-Algorithm
is	O
used	O
in	O
interventional	O
radiology	O
,	O
interventional	O
cardiology	O
and	O
minimally-invasive	O
surgery	O
(	O
e.g.	O
,	O
Hybrid	O
cardiac	O
surgical	O
procedure''	O
)	O
.	O
</s>
<s>
Choosing	O
between	O
CT	O
and	O
rotational	B-Algorithm
angiography	I-Algorithm
depends	O
on	O
several	O
factors	O
.	O
</s>
<s>
An	O
article	O
from	O
the	O
heart	O
center	O
in	O
Leipzig	O
suggests	O
that	O
intraoperative	O
3D	O
imaging	O
with	O
rotational	B-Algorithm
angiography	I-Algorithm
is	O
much	O
more	O
precise	O
and	O
can	O
be	O
performed	O
with	O
low	O
contrast	O
and	O
low	O
radiation	O
dose	O
if	O
combined	O
with	O
diluted	O
contrast	B-Algorithm
injection	I-Algorithm
and	O
rapid	O
ventricular	O
pacing	O
.	O
</s>
<s>
Changes	O
in	O
anatomy	O
:	O
During	O
endovascular	O
procedures	O
,	O
such	O
as	O
the	O
grafting	O
of	O
an	O
aortic	O
aneurysm	O
,	O
3D	O
planning	O
can	O
be	O
done	O
either	O
on	O
CT	O
image	O
acquired	O
preoperatively	O
or	O
on	O
an	O
intraoperative	O
3D	O
image	O
acquired	O
by	O
rotational	B-Algorithm
angiography	I-Algorithm
.	O
</s>
<s>
Image	O
quality	O
can	O
differ	O
between	O
rotational	B-Algorithm
angiography	I-Algorithm
and	O
CT	O
images	O
.	O
</s>
<s>
Image	O
quality	O
is	O
not	O
only	O
defined	O
through	O
artifacts	O
but	O
also	O
through	O
temporal	O
,	O
spatial	O
,	O
and	O
contrast	B-Algorithm
resolution	I-Algorithm
.	O
</s>
<s>
The	O
physical	O
characteristics	O
of	O
a	O
flat-panel	O
detector	B-Application
decrease	O
the	O
temporal	B-General_Concept
resolution	I-General_Concept
as	O
the	O
one	O
of	O
the	O
ceramic	O
detectors	B-Application
used	O
in	O
multidetector	O
CT	O
systems	O
.	O
</s>
<s>
By	O
contrast	O
,	O
the	O
spatial	O
resolution	O
of	O
flat-panel	O
volume	B-Algorithm
CT	I-Algorithm
(	O
rotational	B-Algorithm
angiography	I-Algorithm
using	O
a	O
C-Arm	O
)	O
can	O
be	O
much	O
better	O
than	O
that	O
of	O
a	O
multislice	O
CT	O
scanner	O
,	O
with	O
resolution	O
ranges	O
between	O
200	O
and	O
300	O
μm	O
in	O
high-resolution	O
mode	O
,	O
compared	O
to	O
up	O
to	O
600μm	O
for	O
a	O
multislice	O
CT	O
.	O
</s>
<s>
Contrast	B-Algorithm
resolution	I-Algorithm
,	O
measured	O
in	O
hounsfield	O
units	O
(	O
HU	O
)	O
,	O
is	O
only	O
marginally	O
inferior	O
than	O
with	O
a	O
multidetector	O
CT	O
,	O
the	O
difference	O
in	O
attenuation	O
from	O
the	O
background	O
being	O
5	O
HU	O
with	O
flat-panel	O
volume	B-Algorithm
CT	I-Algorithm
(=	O
rotational	B-Algorithm
angiography	I-Algorithm
)	O
compared	O
to	O
3	O
HU	O
for	O
a	O
multidetector	O
CT	O
.	O
</s>
<s>
X-ray	B-Library
radiation	O
is	O
ionizing	O
radiation	O
,	O
thus	O
exposure	O
is	O
potentially	O
harmful	O
.	O
</s>
<s>
Rotational	B-Algorithm
angiography	I-Algorithm
may	O
increase	O
the	O
exposure	O
of	O
workers	O
to	O
scattered	O
radiation	O
,	O
as	O
the	O
X-ray	B-Library
source	O
moves	O
around	O
the	O
patient	O
.	O
</s>
