Moyamoya disease (MMD) is a nonatherosclerotic cerebrovascular abnormality, characterized by a progressive stenosis or occlusion of the intracranial internal carotid arteries (ICAs) and their proximal branches, with subsequent formation of collateral vessels ("puff of smoke"). In some cases, the posterior circulation can also be involved. MMD has been discovered around the world, but Asians carry the most possibility to develop this disease. Current treatment designed to prevent strokes by improving blood flow to the affected cerebral hemisphere including medical therapy and surgery. In particular, surgery included two general methods: direct and indirect revascularization. Compared with direct bypass, indirect procedures are more technically accessible and may reduce the possibility of complications, such as hyperperfusion. In addition, magnetic resonance imaging (MRI) with derived parameters have shown great potential in evaluating perfusion in patients, and could possibly predict surgical outcome. However, there is still lack of evidence of the predictive value of MRI in evaluating clinical and angiography improvement in patients with MMD.

Imaging protocols:

3D TOF 3SLAB; SWAN; 3D ASL 2.0s; T1; T2; T2 Flair; DWI; tASL 2.0s; DCE; APT-CEST

Imaging evaluation:

1. Transfer contrast volume value measured by DCE;
2. ASL shows CBF in associated regions;
3. Stoke area measured by DWI and Flair;
4. PH values reflected by APT-CEST.

Treatment:

Surgery-indirect revascularization

Follow-up:

Baseline (MRI+DSA); 3-months follow-up (MRI); 6-months follow-up (MRI+DSA)

Inclusion Criteria:

• DSA/MRA shows stenosis or occlusion in the distal internal carotid artery or the proximal portion of anterior/middle cerebral artery;
• Abnormal vascular network appeared in the brain;
• With the onset of cerebral ischemia/hemorrhage/TIA;
• No cerebral infarction or cerebral hemorrhage occurred within the last month;
• All MRI examination performed according to study protocol;
• Signed informed consent obtained from the patient or patient's legally authorized representative;
• Having complete medical history and clinical follow up;
• Imaging data can be processed.

Exclusion Criteria:

• Patients with moyamoya syndrome secondary to systemic diseases such as arteriosclerosis, sickle cell anemia, radiation therapy, etc.;
• Patients with severe mental disorders such as psychosis, liver and kidney dysfunction, poor blood pressure or blood glucose control, severe depression and substance abuse, low IQ, and acute phase of severe stroke with definite limb dysfunction should also be excluded.
• Pregnancy

Patients with Moyamoya disease