Unenhanced helical CT for suspected renal colic.

Abstract

Typical Findings Unenhanced helical images are obtained from the level of the T12 vertebral body to the pubic symphysis, using 5-mm collimation and a pitch of I .7, in one or more breath-holds. A ureteral stone is identified by following the ureter inferiorly to an area of calcification. This is most easily done by paging or scrolling through the images on the CT monitor. SecondWY signs are common and provide evidence that an acute obstructive process is present [2J (Fig. I ): these signs include hydronephrosis, hydroureter, perinephric edema, enlargement of the kidney, periureteric edema. and edema at