BOLD-fMRI and DTI scans are performed to patients with germ cell tumors in the basal ganglia before and after treatments. The changes of the MRI and muscle strength of patients during treatments are evaluated, and the association between these two are investigated.

Primary intracranial germ cell tumors are a specific entity of brain tumors with a variety of histological types and different degrees of malignancy. Intracranial GCTs make up 11.2% - 15.3% of primary intracranial tumors in Asian children compared with 3.6% in the US. And tumors located at the basal ganglia is much rarer.

The investigators realize that most of patients with tumors at this location are involved with motor disfunction. And after treatments, some patients get relieved dramatically, but some others failed to get similar outcomes. To better understand the mechanism causing this difference of treatment outcomes, the investigators perform BOLD-fMRI and DTI scans to patients with germ cell tumors in the basal ganglia before and after treatments. The changes of the fMRI and muscle strength of patients during treatments are evaluated, and the association between these two are investigated.

Inclusion Criteria:

1. age ≥3 years;
2. no history of brain radiotherapy;
3. no other known cause of movement and cognitive impairment;
4. no contraindications to the magnetic resonance imaging (MRI) scan;

Exclusion Criteria:

1. patients can not tolerate MR scan;
2. head motion is greater than 3 mm during functional MRI scanning.

Patients with intracranial germ cell tumor located at the basal ganglia.