<s>
High-resolution	B-Algorithm
computed	I-Algorithm
tomography	I-Algorithm
(	O
HRCT	B-Algorithm
)	O
is	O
a	O
type	O
of	O
computed	O
tomography	O
(	O
CT	O
)	O
with	O
specific	O
techniques	O
to	O
enhance	O
image	B-Algorithm
resolution	I-Algorithm
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
HRCT	B-Algorithm
of	O
the	O
temporal	O
bone	O
is	O
used	O
to	O
diagnose	O
various	O
middle	O
ear	O
diseases	O
such	O
as	O
otitis	O
media	O
,	O
cholesteatoma	O
,	O
and	O
evaluations	O
after	O
ear	O
operations	O
.	O
</s>
<s>
HRCT	B-Algorithm
is	O
performed	O
using	O
a	O
conventional	O
CT	O
scanner	O
.	O
</s>
<s>
In	O
expiratory	O
HRCT	B-Algorithm
the	O
scan	O
is	O
taken	O
in	O
the	O
supine	O
position	O
(	O
face	O
up	O
)	O
.	O
</s>
<s>
As	O
HRCT	B-Algorithm
's	O
aim	O
is	O
to	O
assess	O
a	O
generalized	O
lung	O
disease	O
,	O
the	O
test	O
is	O
conventionally	O
performed	O
by	O
taking	O
thin	O
sections	O
which	O
are	O
10	O
–	O
40mm	O
apart	O
from	O
each	O
other	O
.	O
</s>
<s>
Intravenous	O
contrast	B-Application
agents	I-Application
are	O
not	O
used	O
for	O
HRCT	B-Algorithm
as	O
the	O
lung	O
inherently	O
has	O
very	O
high	O
contrast	O
(	O
soft	O
tissue	O
against	O
air	O
)	O
,	O
and	O
the	O
technique	O
itself	O
is	O
unsuitable	O
for	O
assessment	O
of	O
the	O
soft	O
tissues	O
and	O
blood	O
vessels	O
,	O
which	O
are	O
the	O
major	O
targets	O
of	O
contrast	B-Application
agents	I-Application
.	O
</s>
<s>
The	O
technique	O
of	O
HRCT	B-Algorithm
was	O
developed	O
with	O
relatively	O
slow	O
CT	O
scanners	O
,	O
which	O
did	O
not	O
make	O
use	O
of	O
multi-detector	O
(	O
MDCT	O
)	O
technology	O
.	O
</s>
<s>
As	O
performing	O
contiguous	O
thin	O
sections	O
required	O
unacceptably	O
prolonged	O
scan	O
time	O
,	O
HRCT	B-Algorithm
examination	O
was	O
performed	O
with	O
widely	O
spaced	O
sections	O
.	O
</s>
<s>
Because	O
of	O
the	O
different	O
scan	O
parameters	O
for	O
conventional	O
and	O
HRCT	B-Algorithm
examinations	O
,	O
if	O
a	O
patient	O
required	O
both	O
,	O
they	O
had	O
to	O
be	O
performed	O
sequentially	O
.	O
</s>
<s>
Because	O
of	O
this	O
,	O
it	O
may	O
be	O
possible	O
to	O
reconstruct	O
inspiratory	O
HRCT-like	O
images	O
from	O
the	O
data	O
taken	O
from	O
a	O
'	O
normal	O
 '	O
chest	O
CT	O
scan	O
.	O
</s>
<s>
Alternatively	O
,	O
the	O
scanner	O
could	O
be	O
configured	O
to	O
perform	O
contiguous	O
1mm	O
sections	O
for	O
a	O
HRCT	B-Algorithm
examination	O
-	O
this	O
provides	O
greater	O
diagnostic	O
information	O
as	O
it	O
examines	O
the	O
entire	O
lung	O
,	O
and	O
permits	O
the	O
use	O
of	O
multi-planar	O
reconstruction	O
techniques	O
.	O
</s>
<s>
HRCT	B-Algorithm
is	O
used	O
for	O
diagnosis	O
and	O
assessment	O
of	O
interstitial	O
lung	O
disease	O
,	O
such	O
as	O
pulmonary	O
fibrosis	O
,	O
and	O
other	O
generalized	O
lung	O
diseases	O
such	O
as	O
emphysema	O
and	O
bronchiectasis	O
.	O
</s>
<s>
HRCT	B-Algorithm
may	O
be	O
diagnostic	O
for	O
conditions	O
such	O
as	O
emphysema	O
or	O
bronchiectasis	O
.	O
</s>
<s>
While	O
HRCT	B-Algorithm
may	O
be	O
able	O
to	O
identify	O
pulmonary	O
fibrosis	O
,	O
it	O
may	O
not	O
always	O
be	O
able	O
to	O
further	O
categorize	O
the	O
fibrosis	O
to	O
a	O
specific	O
pathological	O
type	O
(	O
e.g.	O
,	O
non-specific	O
interstitial	O
pneumonitis	O
or	O
desquamative	O
interstitial	O
pneumonitis	O
)	O
.	O
</s>
<s>
The	O
major	O
exception	O
is	O
UIP	O
,	O
which	O
has	O
very	O
characteristic	O
features	O
,	O
and	O
may	O
be	O
confidently	O
diagnosed	O
on	O
HRCT	B-Algorithm
alone	O
.	O
</s>
<s>
Where	O
HRCT	B-Algorithm
is	O
unable	O
to	O
reach	O
a	O
definitive	O
diagnosis	O
,	O
it	O
helps	O
locate	O
an	O
abnormality	O
,	O
and	O
so	O
helps	O
planning	O
a	O
biopsy	O
,	O
which	O
may	O
provide	O
the	O
final	O
diagnosis	O
.	O
</s>
<s>
Other	O
miscellaneous	O
conditions	O
where	O
HRCT	B-Algorithm
is	O
useful	O
include	O
lymphangitis	O
carcinomatosa	O
,	O
fungal	O
,	O
or	O
other	O
atypical	O
,	O
infections	O
,	O
chronic	O
pulmonary	O
vascular	O
disease	O
,	O
lymphangioleiomyomatosis	O
,	O
and	O
sarcoidosis	O
.	O
</s>
<s>
HRCT	B-Algorithm
has	O
better	O
sensitivity	O
for	O
bronchiolitis	O
obliterans	O
than	O
conventional	O
radiography	O
.	O
</s>
<s>
Some	O
transplant	O
centers	O
may	O
arrange	O
annual	O
HRCT	B-Algorithm
to	O
screen	O
for	O
this	O
.	O
</s>
<s>
Diagnostic	O
imaging	O
,	O
including	O
HRCT	B-Algorithm
,	O
is	O
one	O
of	O
the	O
main	O
diagnostic	O
tools	O
for	O
COVID-19	O
.	O
</s>
<s>
Under	O
HRCT	B-Algorithm
scan	O
,	O
infected	O
individuals	O
generally	O
showed	O
a	O
multifocal	O
or	O
unifocal	O
involvement	O
of	O
ground-glass	O
opacity	O
(	O
GGO	O
)	O
.	O
</s>
<s>
The	O
presence	O
of	O
lung	O
nodules	O
on	O
high	B-Algorithm
resolution	I-Algorithm
CT	I-Algorithm
is	O
a	O
keystone	O
in	O
understanding	O
the	O
appropriate	O
differential	O
.	O
</s>
<s>
HRCT	B-Algorithm
temporal	O
bone	O
is	O
used	O
to	O
determine	O
the	O
anatomy	O
of	O
chronic	O
otitis	O
media	O
(	O
middle	O
ear	O
is	O
located	O
inside	O
the	O
temporal	O
bone	O
)	O
,	O
congenital	O
abnormalities	O
,	O
and	O
loss	O
of	O
surgical	O
landmarks	O
due	O
to	O
previous	O
operation	O
.	O
</s>
<s>
Thus	O
,	O
HRCT	B-Algorithm
is	O
useful	O
in	O
surgical	O
planning	O
and	O
management	O
of	O
temporal	O
bone	O
diseases	O
.	O
</s>
