Inclusion Criteria:  Patients who are new to hemodialysis treatment, and those who are on regular hemodialysis treatment for ≥6 months. Age ≥ 18 years old.  Exclusion Criteria:  There was already a severe central nervous system disease before dialysis. Hearing and visual impairment cannot communicate or cooperate. Mental illness and incapacity. The magnetic resonance examination could not be completed for various reasons. Life expectancy with serious diseases is less than 6 months.