Predictive role of non-contrast spiral computerized tomography on spontaneous passage of ureteral stones.

PURPOSE We assessed the role of non-contrast spiral computerized tomography (CT) for prediction of a favorable clinical outcome in patients with ureterolithiasis, presenting with acute flank pain. MATERIALS AND METHODS Consecutive 185 patients having acute flank pain were prospectively evaluated with physical examination, urinalysis and hemogram, and non-contrast spiral CT. Size (greatest width in mm), location, perinephric fat stranding, the degree of hydronephrosis, tissue rim sign and perinephric fluid were assessed with spontaneously passed and unpassed stones. RESULTS Urinary stone disease was investigated in 173 (93.5%) patients out of 185 (mean age = 41.1 years) by non-contrast spiral CT in whom ureterolithiasis was diagnosed in 96 (94 unilateral, 2 bilateral). Spontaneous passage was assumed in 79 patients with ureterolithiasis. Only 38 patients spontaneously passed ureteral stones with less than 7.4mm diameter. The greatest width difference was statistically significant between passed and unpassed group [(2.0-7.4mm; mean 4.37+/-1.63) vs. (4.0-10.0mm; mean 7.35+/-1.81), p<0.05]. CONCLUSIONS Spiral CT seems to be a sensitive imaging modality for the detection of ureteral calculi. In addition, size and location of the ureteral stones and its effects on ureteral wall, as periureteral inflammation and edema, demonstrated by the rim sign, present an important predictive value on spontaneous passage of uretreral stones.