A t1t2 high signal lesion is considered to be a subacute advanced hemorrhagic disease, such as cerebral hemorrhage and subarachnoid hemorrhage; it may also be a fatty mass such as teratoma, fatty liver, and mucin-containing and lipoid cysts. MRI examination causes the phenomenon of nuclear magnetic resonance by emitting specific RF (specific radiofrequency) pulses. After stopping the emission of the pulses, the hydrogen protons rapidly return to their original equilibrium state, a process called relaxation process, and the time required is the relaxation time. The longitudinal magnetic vector recovery time is called T₁ relaxation time, and the transverse magnetic vector recovery decay and disappearance time, T2 relaxation time. The black and white grayscale on the MRI image is called signal intensity, where white shadows are high signal, gray shadows are medium signal, and black shadows are low or no signal. t1 high signal represents tissues with a short longitudinal relaxation time, and is often referred to as a short t1 high signal or a short t1 signal, such as adipose tissue; t2 high signal represents tissues with a long transverse relaxation time, and is often referred to as a short t2 high signal or a short t2 signal. T1t2 high signal, it is recommended to consult a doctor in order to clarify the diagnosis, under the guidance of the doctor for targeted treatment.