The investigators plan a prospective cross-sectional study of pediatric and adult healthy volunteers and patients with chronic kidney disease that will correlate a variety of quantitative MRI biomarkers with severity of renal insufficiency and available histopathology. Over 3 years, the investigators will recruit approximately 20 healthy volunteers, 20 patients with chronic kidney disease (CKD) Stage 2-5, and 20 patients with renal transplant kidneys. The investigators also plan to assess the effect of inflammation on the quantitative MRI biomarkers by recruiting approximately 20 additional patients with active lupus nephritis.

Inclusion Criteria:

Subjects who meet all of the following criteria will be eligible for the study:

1. ≥ 10 and ≤ 25 years of age and;
2. Kidney transplant patients, who have had a recent kidney biopsy (within 1 year) that shows interstitial fibrosis OR
3. Patients with CKD Stage 2-5 who have previously had a biopsy (within 1 year) OR
4. Lupus patients with active nephritis who will undergo biopsy evaluation before and after induction therapy OR
5. Healthy Controls

Exclusion Criteria:

Subjects who meet any of the following criteria will be excluded from the study:

1. Known contraindication to MR imaging (e.g., implanted non-MRI compatible device)
2. Known or suspected pregnancy. Female subjects of child bearing potential will undergo a urine pregnancy test prior to imaging.
3. Inability to undergo MRI without sedation/anesthesia.
4. Non-English Speaking