 In addition to direct studies of the kidney, brain MRI studies will also be performed to identify the cerebrovascular and cognitive effects of chronic renal function deficiency and medical treatment e.g. hemodialysis and immunosuppression. The brain and kidneys have similar vascular bed, and both are susceptible to vascular injury, which provides the pathological basis for the widely recognized association of reduced renal function with prevalent cerebrovascular diseases CVDs and cognitive impairment CI. The MRI methods in the brain will be applied to explore the origins for widely observed CVDs and prevalent cognitive impairment CI in kidney disease patients. 