The objective of this observational study is to investigate the characteristics of the tumor microenvironment in patients with brain tumors using multi-modal magnetic resonance imaging (MRI). The primary research question it aims to address is:

• Can multi-modal MRI effectively characterize features of the immune microenvironment in brain tumor patients?

Participants:

Eligible participants who have been diagnosed with a brain tumor will undergo multi-modal MRI scans for detailed assessment of tumor microenvironment features.

Inclusion Criteria:

1. conventional MRI revealed intracranial space-occupying lesions and suspected high-grade gliomas, brain metastases and meningiomas；
2. It is planned to perform a brain tumor resection surgery in this institution.

Exclusion Criteria:

1. other CNS diseases in addition to brain tumors;
2. pathologically confirmed brain tumors not belonging to any of the three selected types;
3. contraindications to the use of gadolinium contrast, including hypersensitivity to contrast agents, renal dysfunction, pregnancy or lactation;
4. contraindications to MRI;
5. poor image quality unsuitable for subsequent analyses;
6. age younger than 18 years.

Patients with brain tumors