<s>
Cardiac	B-Algorithm
magnetic	I-Algorithm
resonance	I-Algorithm
imaging	I-Algorithm
perfusion	I-Algorithm
(	O
cardiac	B-Algorithm
MRI	I-Algorithm
perfusion	I-Algorithm
,	O
CMRI	O
perfusion	O
)	O
,	O
also	O
known	O
as	O
stress	O
CMR	O
perfusion	O
,	O
is	O
a	O
clinical	O
magnetic	O
resonance	O
imaging	O
test	O
performed	O
on	O
patients	O
with	O
known	O
or	O
suspected	O
coronary	O
artery	O
disease	O
to	O
determine	O
if	O
there	O
are	O
perfusion	O
defects	O
in	O
the	O
myocardium	O
of	O
the	O
left	O
ventricle	O
that	O
are	O
caused	O
by	O
narrowing	O
of	O
one	O
or	O
more	O
of	O
the	O
coronary	O
arteries	O
.	O
</s>
<s>
In	O
contrast	O
to	O
the	O
nuclear	O
imaging	O
modalities	O
(	O
PET	B-Application
and	O
SPECT	O
)	O
,	O
CMR	O
perfusion	O
does	O
not	O
involve	O
the	O
use	O
of	O
ionising	O
radiation	O
and	O
can	O
therefore	O
be	O
used	O
multiple	O
times	O
without	O
the	O
risk	O
to	O
the	O
patient	O
of	O
exposure	O
to	O
radiation	O
.	O
</s>
<s>
Some	O
centers	O
use	O
inotrope	O
dobutamine	O
to	O
stress	O
the	O
heart	O
and	O
the	O
images	O
are	O
interpreted	O
in	O
a	O
similar	O
fashion	O
to	O
dobutamine	B-Application
stress	I-Application
echocardiogram	I-Application
.	O
</s>
<s>
Patients	O
who	O
have	O
heart	B-Algorithm
block	I-Algorithm
on	O
their	O
ECG	O
before	O
the	O
test	O
,	O
as	O
the	O
Adenosine	O
may	O
make	O
this	O
worse	O
.	O
</s>
<s>
There	O
are	O
a	O
number	O
of	O
more	O
serious	O
and	O
much	O
less	O
common	O
side	O
effects	O
,	O
including	O
transient	O
heart	B-Algorithm
block	I-Algorithm
,	O
bronchoconstriction	O
and	O
a	O
1	O
in	O
10,000	O
risk	O
of	O
anaphylaxis	O
caused	O
by	O
the	O
gadolinium	O
contrast	O
agent	O
.	O
</s>
