IOAN SCARNECIU, ALEXANDRU BANUTA, LAURIAN MAXIM, SALVATORE GIORDANO, DRAGOS RADU MARCU, ROXANA BOHILTEA, FLORENTINA IONITA-RADU, FLAVIA LILIANA TURCU, BOGDAN SOCEA, GHEORGHITA ISVORANU, CAMELIA CORNELIA SCARNECIU NON-CONTRAST COMPUTED TOMOGRAPHY AND THE IMPACT OF STONE DENSITY TO CHOOSE MINIMAL INVASIVE TREATMENT Reno-ureteral lithiasis is a common pathology especially in socio-economically developed countries and may pose serious problems with renal function impairment. Urology is currently one of the surgical branches that benefit from a wide range of therapeutic options in reno-ureteral lithiasis, that revolutionized the criteria and indications of the lithiasis pathology, increasing the success rate and decreasing the number of days of hospitalization but which cannot provide satisfactory results if not complemented by imaging examinations. Non-contrast computer tomography is a key element in determining the best method of treatment by measuring the density of stones and increasing the stone-free rate of patients. Measurement of the stones density is done by Hounsfield units (HU), and patients who have had a <500 HU density have pleaded in over 90% for the uric acid composition. We included in our study a batch of 364 patients with reno-ureteral lithiasis and the treatment method was chosen based on the density of the stones: 64.83% of the patients with a density between 200-700 HU performed semi-rigid ureteroscopy and ballistic lithotripsy, 3.57% of patients with density between 700-1000 HU benefited from flexible ureteroscopy and laser lithotripsy, 17.58% of patients with density between 400-700HU performed ESWL and 13.73% with density>1000 HU have benefited from PCNL.