Cerebral
Perfusion Imaging in Hemodynamic
Stroke: Be Aware of the Pattern
R.
Siemund,
M.
Cronqvist,
G.
Andsberg,
B.
Ramgren,
L.
Knutsson,
S.
Holtås
Summary - Reduction
of the
cerebral perfusion
pressure caused
by vessel
occlusion or
stenosis is
a cause
of neurological
symptoms and
border-zone infarctions.
The aim
of this
article is
to describe
perfusion patterns
in hemodynamic
stroke, to
give a
practical approach
for the
assessment of
colour encoded
CT- and
MR-perfusion maps
and to
demonstrate the
clinical use
of comprehensive
imaging in
the workup
of patients
with hemodynamic
stroke. Five
patients with
different duration
cause and
degree of
hemodynamic stroke
were selected.
The patients
shared the
typical presentation
with fluctuating
and transient
symptoms. All
were examined
by MR
or CT
angiography and
MR or
CT perfusion
in the
symptomatic phase.
All patients
were examined
with diffusion
weighted imaging.
All five
cases showed
the altered
perfusion patterns
of hemodynamic
insufficiency with
a slight
or marked
increase in
CBV in
the supply
area of
the affected
vessel and
only slightly
reduced or
maintained CBF.
The perfusion
disturbances were
most easily
detected on
the MTT
maps. Border-zone
infarctions were
seen in
all cases.
The typical
pattern for
hemodynamic insufficiency
is characterized
by increased
CBV, normal
or decreased
CBF and
prolonged MTT
in the
affected areas.
The increased
CBV is
the hallmark
of stressed
autoregulation. Reading
the color-encoded
perfusion maps
enables a
quick and
robust assessment
of the
cerebral perfusion
and its
characteristic patterns.
Internal border-zone
infarctions can
be regarded
as a
marker for
hemodynamic insufficiency.
Finding of
the typical
rosary-like pattern
of DWI
lesions should
call for
further work
up.