lipoma、fluid c、isodense:chronic hamorhage、tumor dheterogeneous density Abnormal change of MRI ●T1WI: 5min a.hyperintensity:fat or lipoid,melanin,constrast medium b.hypointensity:edema、fluid、tumor fibrosis and calcification ·T2W1: 5min a.hyperintensity:edema,fluid、tumor、 b.hypointensity fibrosis and calcification melanin ●mass effect 5minlipoma、 fluid c、 isodense ：chronic hamorrhage、 tumor d、heterogeneous density Abnormal change of MRI ⚫ T1WI： a. hyperintensity：fat or lipoid、melanin、constrast medium b. hypointensity：edema、fluid、tumor fibrosis and calcification ⚫ T2WI： a. hyperintensity ： edema、fluid、tumor 、 b. hypointensity ： fibrosis and calcification 、 melanin ⚫ mass effect 5min 5min 5min