In this study, we are developing new magnetic resonance imaging (MRI) and ultrasound methods to determine if it is effective in diagnosing complication in kidney transplant patients. Participants in this study will involve patients that have had a kidney transplant and are scheduled for a kidney biopsy. The study will also involve a comparison group of healthy individuals that have no history of kidney conditions. Study procedures will include a review of medical history and medications, MRI scan and ultrasound of the abdomen and blood/ urine test.

The purpose of this study is to determine how what you eat and drink (your diet), antibiotics you take, and the bacteria that live in your gut (microbiome) contribute to developing kidney stones. Kidney stone disease, known as nephrolithiasis, is also influenced by products of metabolism (metabolites) that are found in your urine. These factors will be examined in participants at least 4 years of age. Each participant will complete three 24-hour dietary recalls and will provide one stool sample and up to two urine samples. The information from this study will help doctors find new metabolic pathways that can be used for treatment of kidney stones.