1. EP 119 Serial Evaluation in Cerebral Perfusion after Indirect Revascularizatition for Children with Moyamoya Disease Using Dynamic Susceptibility Contrast MR Perfusion Study Ya-Fang Chen 1, Hon-Man Liu 1, Meng-Fai Kuo 2 Department of Medical Imaging 1 and Neurosurgery 2 National Taiwan University Hospital

2. The authors have nothing to disclose.

3. 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

4. NC MMD MR Angiography in Moyamoya Disease Missing M1s/A1s. Moyamoya vessels not as evident as on DSA

5. CBF CBV TTP NC MMD MR Perfusion in Moyamoya Disease Homogeneous TTP

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

7. Materials and Methods  Jan 2012 to Dec 2014  17 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)

8.  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 Methods Quantification of time to peak (TTP) map TTP map TTP prolongation map

9. Results (1) Imaging changes after indirect EC-IC bypass  MRI: Ivy sign decrease  MR Angiography  Enlargement of superficial temporal artery and/or middle meningeal artery  Progressive narrowing of MCA/ACA  MR Perfusion: regionally decreased TTP on the operation side

10. 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 TTP left EDAS

11. Post-operative MRA changes Bilateral EDAS Enlargement of superficial temporal artery and middle meningeal artery

12. Right EDAS 3m STA enlargement MMA enlargement 1m

13. Left EDAS 1m 3m MRA changes correlate with MRP improvements

14. 1m 3m Left EDAS

15. Results (2) Quantification of TTP changes  35.7% (10/28) of the 1 st month follow-up showed more than 5% volume improvement of impaired cerebral perfusion.  62.5% (10/24) of the 6 th 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.

16. Right EDASLeft EDASfrontal burr holes 3m 5m 7m TTP map of a 12 y/o girl

17. TTP prolongation map (>2sec) Right EDASLeft EDASfrontal burr holes 3m 5m 7m

18. 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

19. Decrease in TTP prolonged brain volume after indirect bypass (10 patients for illustration) Post-op months Percentage of perfusion impairment

20. Pre-op percentage of perfusion impairment Amount of improvement correlates with initial amount of perfusion impairment Amount of improvement at 6 month

21. Conclusion  DSC MR perfusion offers a quick and noninvasive evaluation of cerebral perfusion in the postoperative moyamoya subjects  Perfusion improvements occur early in the 1 st month after indirect bypass and stabilize at about 6 th month  The rate of the increase in postoperative cerebral perfusion may depend on  Degree of ischemia  Progression of the disease  Others