To explore the feasibility of low-dose CT urography-assisted positioning of PCNL.

Ten patients with upper urinary calculi requiring PCNL treatment were selected. All patients underwent conventional dose (250 mA) CT in excretion and then low dose (50 mA) scan was taken immediately. Signs of upper urinary tract calculi, degree of hydronephrosis, situation of perirenal tissues and organs and location parameters (angle of puncture, depth of puncture) of the two groups of images were assessed independently; statistical analysis was conducted on the two groups of data.

The two groups of images could meet the imaging diagnosis. Regarding conventional dose CTU image as the reference standard, low dose CTU could show the signs of calculi and situation of perirenal tissues completely. Low dose and conventional dose CTU presented no statistically significant difference (P>0.05) in location parameters and conformation of renal calyx, but in effective radiation (P<0.01).

For patients with upper urinary calculi who are suitable for PCNL treatment, low dose CTU scan can substitute for conventional dose CTU scan and become the preferred location method when CTU scan is applied, and it can effectively reduce the radiation level in patients during perioperative period.