Bone Density and Vascular Calcifications Evolution After Renal Transplant

The investigators project is based on: * Assessment of bone architecture by high resolution peripheral scanner (HRpQCT) and bone densitometry (DEXA); * The non-invasive detection of vascular calcifications (by abdominal CT scanner) and bone abnormalities associated with kidney transplantation, as well as the analysis of evolution over time; * Longitudinal evaluation of nephrological clinical parameters (glomerular filtration rate, number and type of rejections, immunosuppressive medications) as well as biological and urinary parameters of mineral metabolism (parathormone, sclerostin, bone alkaline phosphatase) depending on the type and severity of bone abnormalities; * The evaluation of these nephrological clinical parameters and of the biological parameters of mineral metabolism depending on the extent and evolution of vascular calcifications but also on bone morphology; * The study of possible relationships between bone mass and muscle mass (and functioning)