The goal of this observational study is to learn if PRAT thickness is a marker of visceral obesity and its influence on donors' kidney function and blood pressure in living kidney donors. Population includes male/female, 18 years and up, living kidney donors scheduled for nephrectomy within 6 months, with a BMI of ≤ 27 or \>30, with a PRAT thickness measurement of ≥ 14mm or ≤10mm on CT. The main area it aims to help in, is future care managing blood pressure and obesity in living kidney transplant donors. Primary Hypothesis: We hypothesize that Perirenal Fat Thickness (PRAT) may exhibit expansion, remodeling and inflammation that can negatively affect renal outcomes in LKDs. Researchers will compare PRAT morphology and inflammation in LKDs with low and high PRAT thickness. We will also correlate PRAT thickness with renal outcomes including vascular remodeling, at the time of donation and worsening hypertension and inadequately increased compensatory GFR of the LKD at 4-6 months post-donation. Participants will be separated into one of two groups depending on their PRAT measurement and asked to give samples of their blood, perinephric fat, and urine as research samples. Clinically we will abstract data up to 6 months prior and 6 months after their nephrectomy that includes laboratory findings, CT measurements, vitals, exam data, demographics, medical history and current medications.