1. When
magnetic
resonance imaging (MRI) and magnetic
resonance
angiography (MRA) fulfill all the following
requirements which are included in
the diagnostic
guideline using conventional catheter
cerebral
angiography, catheter angiography is
not
necessarily required.
1) MRA
shows
the steno-occlusive changes at the
terminal
portion of the intracranial internal
carotid
artery and proximal portions of the
anterior
and middle cerebral arteries.
2) MRA
shows
abnormal vascular network at the base
of
the brain.
Note: 2') when MRI
shows
at least two flow voids on one side
in the
basal ganglia, they can be regarded
as abnormal
network.
3) Both
1)
and 2) are observed bilaterally.
2. Imaging
methods
1) MR
scanner
is operated at 1.0 tesla or above.
2) Sequences
of MRA are not specified.
3. Adults moyamoya
disease is occasionally similar to the vascular
disease with other etiologies. Thus, diagnosis
solely with MRI and MRA should be reserved
for pediatric moyamoya disease.
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