Cerebral MRI with long T1 and long T2 signals is commonly seen in central system tumors, cerebral infarction foci and cerebral hemorrhage, etc. T2 is high signal, white color shows lesions; T1 is low signal, black color shows normal anatomical structures. 1. Tumor of the central system: generally the mass has high water content and shows high signal on T2. If it is a fatty mass, T1 and T2 both show high signal. Melanoma containing paramagnetic material presents high signal on T1. 2. Cerebral infarction foci: generally, in acute and chronic cerebral infarction, due to cerebral edema, necrosis, cystic degeneration, T2 will be high signal. 3. Cerebral hemorrhage: in subacute early cerebral hemorrhage, T1 and T2 are long signals, and a signal ring with ferritin deposition can appear around the hemorrhage foci in the brain. The signal ring is more obvious in the chronic stage. If the brain MRI signal is abnormal, you need to go to the hospital as soon as possible to receive professional medical treatment, so as not to delay the condition.