MRI Signal Characteristics of brain tumor which aid in diagnosis

Normally brain tumors appears Hypointense on T1 and Hyperintense on T2.
But a handful of tumors don't follow this rule and aid in narrowing down the diagnosis.

HIGH SIGNAL ON T1W

METHEMOGLOBIN : Hemorrhage into tumor or aneurysm, apoplexy, thrombosed aneurysm

PROTEINACEOUS MATERIAL : Protein containing cysts - dermoid cysts and neuroenteric cysts.

FAT - Lipoma and dermoid cysts

CHOLESTEROL - Colloid cysts

MELANIN- Melanoma metastasis

PARAMAGNETIC CATIONS - CU,MG etc

LOW SIGNAL INTENSITY ON T2W


HYPERCELLULARITY -Lymphoma, meningioma, pnet, germinoma ,GBM, oligodendroglioma,
                                          Mucinous -adeno metastases

CALCIFICATION  - oligodendroglioma , Astrocytoma,

BLOOD - old hemorrhage in tumour or vascular malformations

PROTEIN - colloid cyst

MELANIN - melanoma metastastases

FLOW EFFECTS - Hemangioblastoma , vascular malformations