[Helical CT without contrast media as alternative to other methods in urolithiasis]. / La Tc spirale senza mdc in alternativa alle altre metodiche nella urolitiasi.

PURPOSE: During the last five years the use of unenhanced helical CT (HTC) has been proposed as a preliminary diagnostic approach in patients with typical renal colics or with nonspecific flank pain. The aim of this study was to describe our experience in this field. MATERIAL AND METHODS: 130 consecutive patients (82 men and 48 women, with an average age of 54 years) were studied; 94 of them presented typical renal colics, while 36 presented acute flank pain. The parameters used were: 5-mm-thick sections, a pitch of 1.6, a reconstruction interscan spacing at 3 mm, an examination area extending from the kidneys to the base of the bladder. Depending on the case, examinations were carried out using urography in the instrumental or surgical pretreatment phase, ultrasonography to check urinary dilatation and juxtavesical calculi, pyeloMR, ureteroscopic extraction, surgical operation, extracorporeal lithotripsy, and finally the expulsion of the calculi was checked. RESULTS: 81 cases of urolithiasis, 6 cases of renal abnormalities and other renal pathologies, 23 cases of extraurinary pathologies correlated to the symptoms, 5 cases of extraurinary pathologies not correlated to the symptoms and 15 normal cases, were diagnosed. The results obtained were a) a sensitivity of 96.8%, a specificity of 98.4% and a diagnostic accuracy of 97.6% in identifying ureteral calculi; b) a diagnostic accuracy of 100% in identifying urinary tract dilatation; c) a sensitivity of 100% and a specificity of 96.7% in determining the level of obstruction; d) a sensitivity of 92.9% and a specificity of 100% in determining the cause of obstruction. CONCLUSIONS: Confirming the data in the medical literature, helical CT has yielded for more reliable results than the other procedures in identifying the following: calculi, acute obstruction of the urinary tract and other urinary and extraurinary pathologies correlated to the symptoms. Therefore helical CT, where available, must be accepted as the method of preliminary evaluation in all patients with typical renal colics or with nonspecific flank pain.