EP 119Serial Evaluation in Cerebral Perfusion after Indirect

Revascularizatition for Children with Moyamoya Disease Using Dynamic Susceptibility Contrast MR

Perfusion Study

Ya-Fang Chen1, Hon-Man Liu1, Meng-Fai Kuo2

Department of Medical Imaging1 and Neurosurgery2

National Taiwan University Hospital

The authors have nothing to disclose.

Angiography in Moyamoya disease

NC MMD

• Progressive stenosis of the terminal portion of the internal carotid artery and its main branches

• Extensive development of collaterals

Missing M1 /A1

Prominent basal moyamoya

NC

MMD

MR Angiography in Moyamoya Disease

Missing M1s/A1s.Moyamoya vessels not as evident as on DSA

CBF CBV TTP

NC

MMD

MR Perfusion in Moyamoya DiseaseHomogeneous TTP

Purpose

To evaluate serial changes in MR Angiography and dynamic susceptibility contrast (DSC) MR Perfusion in children who undergo indirect revascularizatition for Moyamoya disease

Materials and Methods

Jan 2012 to Dec 201417 children (younger than 18 years), 6 girls and 11 boys Encephaloduroarteriosynangiosis (EDAS) was done

sequentially on both sides or only on one side with a total of 31 EDAS done

Serial MR evaluation before operation and 1m, 3m, 6m, 9m, 12m after operation (GE Excite, Signa HDx) TOF MRA of whole brain DSC MR perfusion (TR/TE, 2000/40ms, FA:90)

Using cerebellar average TTP as the reference, those regions with more than 2secs prolonged TTP were regarded perfusion impaired. The volume of perfusion impaired brain was calculated on each side (Osirix, global thresholding)

Percentage of perfusion impairment= volume of perfusion impaired brain divided by the supratentorial intracranial volume

Materials and MethodsQuantification of time to peak (TTP) map

TTP map

TTP prolongation map

Results (1) Imaging changes after indirect EC-IC bypass

MRI: Ivy sign decreaseMR Angiography

Enlargement of superficial temporal artery and/or middle meningeal artery

Progressive narrowing of MCA/ACAMR Perfusion: regionally decreased TTP on the

operation side

Ivy sign on FLAIR fine vascular network over the pial surface due to prominent collaterals

left EDAS

TTP map

Decreased IVY sign on FLAIR

Shortened TTPleft EDAS

Post-operative MRA changes

Bilateral EDAS

Enlargement of superficial temporal artery and middle meningeal artery

Right EDAS

3m

STA enlargement

MMA enlargement

1m

Left EDAS

1m 3m

MRA changes correlate with MRP improvements

1m 3m

Left EDAS

Results (2)Quantification of TTP changes

35.7% (10/28) of the 1st month follow-up showed more than 5% volume improvement of impaired cerebral perfusion.

62.5% (10/24) of the 6th month follow-up showed a more than 5% volume improvement.

Most of the cerebral perfusion status stabilized after 6 months.

Hemispheres with poorer perfusion before operation tend to have a larger improvement after operation.

Right EDAS

Left EDAS

frontal burr holes

3m

5m

7m

TTP map of a 12 y/o girl

TTP prolongation map (>2sec)

Right EDAS

Left EDAS

frontal burr holes

3m

5m

7m

Rt EDAS

Lt EDAS

Frontal burr holes

Decrease in TTP prolonged brain volume after indirect bypass (a 12 y/o girl for illustration)

Post-op months

Percentage of perfusion impairment

Decrease in TTP prolonged brain volume after indirect bypass (10 patients for illustration)

Post-op months

Percentage of perfusion impairment

Pre-op percentage of perfusion impairment

Amount of improvement correlates with initial amount of perfusion impairment

Amount of improvement at 6 month

Conclusion

DSC MR perfusion offers a quick and noninvasive evaluation of cerebral perfusion in the postoperative moyamoya subjects

Perfusion improvements occur early in the 1st month after indirect bypass and stabilize at about 6th month

The rate of the increase in postoperative cerebral perfusion may depend on Degree of ischemia Progression of the disease Others