Patients who are overweight or obese, diabetic or not, share with those who are suffering from uric stones the same way to remove abnormal acidity of the body in urine, ie a kidney ammoniogenesis default. This results in an overly acidic urine pH which is directly pathogenic in people predisposed to develop uric stones because the precipitation of urate soluble uric acid is accelerated in acid medium.

Excess visceral fat, particularly perirenal, this defect may promote formation of renal ammonium. Indeed, the perirenal fat is adjacent to the renal cortex and shares with it a common arterial supply via the plexus Turner. Adipokines and fatty acids of the perirenal fat are predisposed to gain the renal cortex, seat of the ammoniogenesis. In humans the pathogenic role of the perirenal fat is demonstrated in chronic kidney disease and essential hypertension. However, the amount of fat and perirenal that of intra-abdominal fat are positively correlated.

Investigators hypothesis is that the perirenal fat also exert a pathogenic role in uric because of anatomical links between kidney stones and greasy environment and because excess fatty acids reaching the renal cortex decreases ammoniogenesis in an animal model metabolic syndrome.

For the test, the investigators will compare the amount of fat and perirenal renal ability to form ammonium in patients with uric or calcium lithiasis taking into account the amount of intra-abdominal fat.

Inclusion Criteria:

• Urolithiasis Uric defined by more than 90% of uric acid anhydrous and / or dihydrate or calcium lithiasis defined by more than 90% mono calcium oxalate and / or dihydrate, and / or carbapatite and / or brushite;
• Overweight and obesity defined by 25 \