Cerebral Vasospasm after Subarachnoid Hemorrhage: Imaging with ...

Symposium Neuroradiologicum 2010
Maria T. Schmook
Division of Neuroradiology & Musculoskeletal Radiology
Department of Radiology, Medical University of Vienna

• Background information on vasospasm
• CTA & CTP as diagnostic tools
• Comparison of imaging modalities
• Case presentation

• Frequent complication of aneurysmal SAH
• High prevalence (70%)*
• 1.5-3 fold increase in mortality
• DCI is a serious complication of vasospasm
– 50% develop ischemic neurologic deficits*
DCI = delayed cerebral ischemia * Van Gijn et al 2001

Cerebral Vasospasm -Diagnosis
• Best clinical indicator
• new neurologic deficits
• Imaging modalities
• Transcranial Doppler sonography
• Unhenhanced CCT
• CTA & CT perfusion
• MRI & MR perfusion
• Gold standard DSA
• Prompt treatment can
improve neurologic outcome

Vasospasm in CT Angiography
• Pros
– Non-invasive
– Rapid data
acquision
– minimal sedation
sufficient if necessary
– High specificity
(95%)*
– High NPV (94%)*
• Cons
– Low sensitivity (75.6%)
– Coil artifacts interfere
with vessel evaluation
– Reduced accuracy for
distal ICA # & distal
branches
– DD hypoplasia
/vasospasm can be
difficult
* Wintermark et al 2006 # Bighani et al 2007

• 52a patient with AcoA aneurysm

• 52a patient with AcoA aneurysm

• 52a patient with AcoA aneurysm

• Vasospasm 3d after GDC embolisation

Vasospasm in CT Perfusion
• Pros
– Non-invasive
– Rapid data
acquision &
processing
– Equivalent results
to MR perfusion
– Widely available
in emergency
setting
• Cons
– Limited anatomical
coverage
– Motion artifacts
interfere with
evaluation
– Less suitable for
posterior fossa
strokes, small infarcts
– Radiation dose

efore
after GDC embolisation
• 33a patient with aneurysmal SAH, day 0

• 33a patient with MCA Aneurysm & SAH

TTP
CBF
• 33a patient with aneurysmal SAH
CBV

Day 0 Day 7
Day 8
Day 26
• 33a patient with aneurysmal SAH

Day 8
Day 4
Day 3
Day 0 Day 7
Papaverine . i. a.
Day 26
• 33a patient with aneurysmal SAH
Day 7
TTP
Papaverine i. a

Dx of Vasospasm: MTT (6.4s): highest accuracy, sensitivity & NPV
Wintermark et al, AJNR 2006

• Diagnosis of vasospasm requiring endovascular therapy
– Best predictor: cortical rCBF (≥39.3ml/100g/min)
– Highest NPV: MTT (≤7.6s)
• Combined CTA & PCT represents an accurate screening test
– High specificity of CTA & high sensitivity of PCT
– This approach may help to decrease the number of invasive DSA in
selected lower-risk patients
Wintermark et al, AJNR 2006

TTP MTT
CBF CBV
Wintermark et al 2006

Wintermark et al 2006

• As a diagnostic tool for DCI,
qualitative assessment of CTP is
overall superior to NCT and CTA
•It could be useful for fast
decision-making and guiding
treatment
Dankbaar et al, Stroke 2009

Dankbaar et al, Neuroradiology 2009
• Significant CBF difference (21%) between flow
territories of severe and no vasospasm
• In 65%, flow territory of most spastic vessel
corresponded with least perfused region
• Delayed cerebral ischemia in 35% of patients
• In 57/38%21% of pts with severe/moderate/without
vasospasm

Radiation dose!
Loftus M et al , AJR 2010
•Unenhanced CT 1.5-2.5mSv, CTA 2.5 mSv, CTP 1-6.7 mSv

Conclusion
• Combined CTA & PCT represents an accurate
and easy-to-use diagnostic test to assess
vasospasm & brain perfusion
• CTA & PCT may help in reducing the number
of invasive DSA examinations in selected
lower-risk patients
THANK YOU!