Purpose: To compare the diagnostic efficacy and costs of native spiral-CT a
nd intravenous urography (IVU) in the management of patients with acute fla
nk pain. Method: Native spiral-CT and IVU (following about 30 minutes after
CT) were compared in 66 patients with acute frank pain followed by an IVU.
The spiral-CT protocol was: 5-mm section thickness, 7.5-mm table feed and
3-mm increment. The analysis conducted independently by two radiologists en
tailed: (a) Morphology: presence of stone disease (yes-no), localization an
d size of calculi, periureteral and perirenal stranding, dilatation of the
collecting system, and possible alternative diagnoses and (b) cost-effectiv
eness: direct and indirect costs. Results: Fifty-two patients had urolithia
sis. The detection rate of renal and ureteric calculi was significantly hig
her with native spiral-CT than with NU (100% vs. 69%, respectively) (p < 0.
05). A specific sign of ureteric calculi was the so-called soft tissue "rim
sign" (sensitivity 82% and specificity 100%, respectively). In 13 of 14 pa
tients with acute flank pain with no evidence of urolithiasis alternative d
iagnoses could be made by spiral-CT. Spiral-CT was significantly more cost-
effective than IVU in management. Conclusion: Native spiral-CT is faster, m
ore effective and less expensive than IVU in the management of patents with
acute flank pain. Additionally, it poses less risk and has the capability
for allowing alternative diagnoses. Therefore, unenhanced spiral-CT should
be the first line modality in patients with acute flank pain.