<s>
Cholescintigraphy	B-Algorithm
or	O
hepatobiliary	B-Algorithm
scintigraphy	I-Algorithm
is	O
scintigraphy	O
of	O
the	O
hepatobiliary	O
tract	O
,	O
including	O
the	O
gallbladder	O
and	O
bile	O
ducts	O
.	O
</s>
<s>
The	O
image	O
produced	O
by	O
this	O
type	O
of	O
medical	B-Application
imaging	I-Application
,	O
called	O
a	O
cholescintigram	O
,	O
is	O
also	O
known	O
by	O
other	O
names	O
depending	O
on	O
which	O
radiotracer	O
is	O
used	O
,	O
such	O
as	O
HIDA	B-Algorithm
scan	I-Algorithm
,	O
PIPIDA	B-Algorithm
scan	O
,	O
DISIDA	B-Algorithm
scan	O
,	O
or	O
BrIDA	O
scan	O
.	O
</s>
<s>
For	O
example	O
for	O
cholecystitis	O
,	O
cheaper	O
and	O
less	O
invasive	O
ultrasound	B-Application
imaging	I-Application
may	O
be	O
preferred	O
,	O
while	O
for	O
bile	O
reflux	O
cholescintigraphy	B-Algorithm
may	O
be	O
the	O
first	O
choice	O
.	O
</s>
<s>
The	O
investigation	O
is	O
usually	O
conducted	O
after	O
an	O
ultrasonographic	B-Application
examination	O
of	O
the	O
abdominal	O
right	O
upper	O
quadrant	O
for	O
a	O
patient	O
presenting	O
with	O
abdominal	O
pain	O
.	O
</s>
<s>
Cholescintigraphy	B-Algorithm
for	O
acute	O
cholecystitis	O
has	O
sensitivity	O
of	O
97%	O
,	O
specificity	O
of	O
94%	O
.	O
</s>
<s>
Several	O
investigators	O
have	O
found	O
the	O
sensitivity	O
being	O
consistently	O
higher	O
than	O
90%	O
though	O
specificity	O
has	O
varied	O
from	O
73	O
–	O
99%	O
,	O
yet	O
compared	O
to	O
ultrasonography	O
,	O
cholescintigraphy	B-Algorithm
has	O
proven	O
to	O
be	O
superior	O
.	O
</s>
<s>
Cholescintigraphy	B-Algorithm
is	O
also	O
used	O
in	O
diagnosis	O
of	O
the	O
biliary	O
dyskinesia	O
.	O
</s>
<s>
Most	O
radiotracers	O
for	O
cholescintigraphy	B-Algorithm
are	O
metal	O
complexes	O
of	O
iminodiacetic	O
acid	O
(	O
IDA	O
)	O
with	O
a	O
radionuclide	O
,	O
usually	O
technetium-99m	O
.	O
</s>
<s>
This	O
metastable	O
isotope	O
has	O
a	O
half-life	B-Application
of	O
6	O
hours	O
,	O
so	O
batches	O
of	O
radiotracer	O
must	O
be	O
prepared	O
as	O
needed	O
using	O
a	O
moly	O
cow	O
.	O
</s>
<s>
These	O
radiopharmaceuticals	B-Algorithm
include	O
the	O
following	O
:	O
</s>
<s>
Nonproprietary	O
drug	O
name	O
(	O
USP	O
format	O
)	O
Common	O
chemical	O
name	O
Acronym	O
Comments	O
technetium	O
Tc	O
99m	O
lidofenin	O
hepatobiliary	B-Algorithm
iminodiacetic	I-Algorithm
acid	I-Algorithm
;	O
dimethyl-iminodiacetic	O
acid	O
HIDA	O
An	O
early	O
and	O
widely	O
used	O
tracer	O
;	O
not	O
used	O
as	O
much	O
anymore	O
,	O
as	O
others	O
have	O
progressively	O
replaced	O
it	O
,	O
but	O
the	O
term	O
"	O
HIDA	B-Algorithm
scan	I-Algorithm
"	O
is	O
sometimes	O
used	O
even	O
when	O
another	O
tracer	O
was	O
involved	O
,	O
being	O
treated	O
as	O
a	O
catch-all	O
synonym	O
.	O
</s>
<s>
The	O
word	O
cholescintigraphy	B-Algorithm
(	O
)	O
uses	O
combining	O
forms	O
of	O
chole	O
-	O
+	O
scinti(llation )	O
+	O
-graphy	O
,	O
most	O
literally	O
"	O
bile	O
+	O
flash	O
+	O
recording	O
"	O
.	O
</s>
