Multi-Parametric MRI for Renal Transplantation

To achieve these goals, the investigators will perform pilot MRI studies with kidney transplant patients. The investigators will study if MRI can reflect different levels of kidney function. The investigators will also evaluate if MRI can differentiate causes for declining kidney function. Finally, the investigators will explore how MRI measures changes before and after medical treatment for worsening kidney function.

Subjects may be invited for MRI exams with different exam options. An MRI exam may use either of two types of MRI machines at the CMRR: the 3T scanner and the 7T scanner. Subjects may also be invited for a multi-session exam. A description of the MRI exam types with different exam options and the types of multi-session exams is provided later in this document.

• Magnetic Resonance Imaging (Device), also known as MRI: Investigate anatomic and functional characteristics of transplant kidneys using MRI

Primary outcomes

• Anatomic and functional MRI characteristics in transplant kidneys with stable renal function [Baseline]: Investigate the correlations between anatomic and functional characteristics by MRI and the level of transplant renal function

Secondary outcomes

• Anatomic and functional MRI characteristics of transplant kidneys with transplant complications [Baseline]: Investigate the anatomic and functional MRI characteristics of transplant kidneys with transplant complications with comparisons with those from transplant kidneys having stable renal function

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* Renal Transplant Recipients
* Capable to consent
* English speaking
* For studies with patients with fast worsening renal function: An abrupt (within 48 h) reduction in kidney function currently defined as a percentage increase in serum creatinine of ≥50% (1.5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 mL/kg/h for more than 6 h).
* For patients with recovered renal allograft function after therapy: renal allograft function as measured by glomerular filtration rate (eGRF) has been recovered and stabilized above a clinical acceptable level, such as 15 ml/min/1.73 mm2.

Exclusion Criteria:

* On dialysis due to renal allograft failure
* Acute and chronic pulmonary disease
* Pregnancy as reported in CMRR Safety Screen
* Ferromagnetic implants
* Any foreign metal objects in the body
* History of shrapnel or shot gun injury
* Cardiac pacemakers
* Defibrillator
* Neuronal stimulator
* Magnetic aneurysm clip
* Large tattoos on the abdomen or the brain and neck, as determined by CMRR Safety Officer
* Hip replacement
* Too large to fit in the magnet (BMI >= 40, approx.)
* Severe claustrophobia