Unenhanced helical CT in the evaluation of the urinary tract in children and young adults following urinary tract reconstruction: comparison with sonography

Purpose. To compare the accuracy of unenhanced, helical CT with sonography for the detection of complications of urinary tract reconstruction. Materials and methods. Forty-six kidneys in 24 patients were examined with CT and sonography All scans were assessed for ease of renal visualization, presence of renal, ureteral, and bladder calculi, renal scars, hydronephros is, and abdominal wall hernia. The results of both imaging modalities were independently reported. Results. CT provided excellent visualization of all 46 kidneys, while sonog raphy provided poor visualization of 8 kidneys (17%) (P < 0.001). CT detect ed calculi in 10 kidneys, 1 ureter, and 7 bladders. Sonography detected cal culi in only 2 kidneys, and 2 bladders. Overall, CT detected significantly more calculi than VS (18 vs 4, P = 0.01). CT detected scarring in 15 kidney s, while sonography detected scarring in 10. Hydronephrosis was detected in 6 kidneys by CT and in 8 kidneys by sonography. Three abdominal wall herni as were seen at CT that were not seen at sonography. Conclusion. CT is superior to sonography for the detection of urinary tract calculi and renal scarring. CT will demonstrate abdominal wall hernias tha t are unsuspected.