Nonenhanced helical CT and US in the emergency evaluation of patients with renal colic: prospective comparison.
OBJECTIVE
To compare nonenhanced helical computed tomography (CT) with ultrasonography (US) for the depiction of urolithiasis.


METHODS
During 9 months, 45 patients (mean age, 44 years; mean weight, 92.5 kg) prospectively underwent both nonenhanced helical CT (5-mm collimation; pitch of 1.5) and US of the kidneys, ureters, and bladder. US evaluation included a careful search for ureteral calculi. Presence of calculi and obstruction and incidental diagnoses were recorded. Clinical, surgical, and/or imaging follow-up data were obtained in all patients. The McNemar test was used to compare groups.


RESULTS
Diagnoses included 23 ureteral calculi and one each of renal cell carcinoma, appendicitis, ureteropelvic junction obstruction, renal subcapsular hematoma, cholelithiasis, medullary calcinosis, and myelolipoma. CT depicted 22 of 23 ureteral calculi (sensitivity, 96%). US depicted 14 of 23 ureteral calculi (sensitivity, 61%). Differences in sensitivity were statistically significant (P: =.02). Specificity for each technique was 100%. When modalities were compared for the detection of any clinically relevant abnormality (eg, unilateral hydronephrosis and/or urolithiasis in patients with an obstructing calculus), sensitivities of US and CT increased to 92% and 100%, respectively. One case of appendicitis was missed at US, whereas medullary calcinosis and myelolipoma were missed at CT.


CONCLUSIONS
Nonenhanced CT has a higher sensitivity for the detection of ureteral calculi compared with US.
Sheafor
D H
DH
Department of Radiology, Duke University Medical Center, Box 3808, Erwin Rd, Durham, NC 27710, USA. sheaf001@mc.duke.edu
Hertzberg
B S
BS
Freed
K S
KS
Carroll
B A
BA
Keogan
M T
MT
Paulson
E K
EK
DeLong
D M
DM
Nelson
R C
RC
D000328:Adult; D000368:Aged; D001835:Body Weight; D003085:Colic / Q000000981:diagnostic imaging; D004630:Emergencies; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging; D007674:Kidney Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D014514:Ureteral Calculi / Q000000981:diagnostic imaging; D001744:Urinary Bladder Calculi / Q000000981:diagnostic imaging; D014545:Urinary Calculi / Q000000981:diagnostic imaging*