Comparison of helical computerized tomography and plain radiography for estimating urinary stone size.

Purpose: We evaluated the accuracy of noncontrast spiral computerized tomography (CT) for determining urinary stone size compared with plain x-ray.

Materials And Methods: We retrospectively analyzed noncontrast helical CT and plain x-ray of the kidneys, ureters and bladder images of 39 patients with urolithiasis who underwent each study from July 1997 to February 1999. Stone size on x-ray was measured in the craniocaudal and transverse dimensions by a single radiologist (I.

Acute ureterolithiasis: nonenhanced helical CT findings of perinephric edema for prediction of degree of ureteral obstruction.

Purpose: To determine whether the extent of perinephric edema on helical computed tomographic (CT) images without contrast material enhancement can be used to predict the degree of ureteral obstruction in patients with acute ureterolithiasis.

Materials And Methods: Nonenhanced helical CT and excretory urographic images in 82 patients with flank pain were retrospectively reviewed. For each patient, a radiologic diagnosis was established, and the degree of ureteral obstruction determined on urograms was compared with the extent of perinephric edema assessed on CT images.

Ureterolithiasis: value of the tail sign in differentiating phleboliths from ureteral calculi at nonenhanced helical CT.

Purpose: To determine the value of the tail sign in differentiating phleboliths from ureteral calculi at nonenhanced helical computed tomography (CT).

Materials And Methods: The nonenhanced helical CT scans in 82 patients with a confirmed diagnosis of pelvic ureterolithiasis were retrospectively reviewed. Each calcification along the ureter was classified as a phlebolith or a ureteral calculus on the basis of clinical and imaging findings and was analyzed for the presence of a tail sign.

Ureterolithiasis: can clinical outcome be predicted with unenhanced helical CT?

Purpose: To evaluate the use of helical computed tomography (CT) without contrast material enhancement for prediction of a favorable outcome in ureterolithiasis.

Materials And Methods: CT studies were reviewed in 69 patients with a single ureteral stone not located at the ureteropelvic junction. CT findings (tissue rim sign, hydronephrosis, perinephric fat stranding, perinephric fluid collections, and thickening of renal fascia) were graded on a scale of 0-3.

Noncontrast helical CT for ureteral stones.

Noncontrast helical computed tomography (CT) has recently been found to be superior to excretory urography (IVU) in the evaluation of patients with suspected ureterolithiasis. Noncontrast helical CT does not require the use of intravenous contrast material with its associated cost and risk of adverse reactions and can be completed within 5 min, in most cases. Noncontrast CT often detects extraurinary pathology responsible for the patient's symptoms.