title: Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service.
abstract: OBJECTIVE
  To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic.
  
  
  METHODS
  A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which completely replaced the intravenous urogram (IVU) with unenhanced multidetector CT (CT KUB).
  
  
  RESULTS
  The positive rate for urolithiasis was 44% (221/500), the negative rate 46% (229/500) and the rate of other significant findings was 12% (59/500). Female patients had a low positive rate compared with male patients (27.5 versus 57.5%; p<0.001). Urological intervention was required in 28% (61/221) and these patients had a larger average stone size (6.6 versus 3.7 mm; p<0.001) and the stone was located more proximally. Out-of-hours imaging was performed in 37% (186/500), and these patients had a higher positive rate (52 versus 40%; p<0.001). Other findings included a wide range of acute non-urological conditions.
  
  
  CONCLUSIONS
  The feasibility of replacing the acute IVU with CT KUB in the initial assessment of suspected acute renal colic was demonstrated in the present study. The technique enables rapid diagnosis of urolithiasis, stratification of patients likely to proceed to urological intervention, and prompt diagnosis of a variety of other acute pathological conditions.
authors.affiliation: Department of Clinical Radiology, Leeds Teaching Hospitals, Leeds, UK.
authors.forename: F U
authors.initials: FU
authors.lastname: Chowdhury
authors.forename: S
authors.initials: S
authors.lastname: Kotwal
authors.forename: G
authors.initials: G
authors.lastname: Raghunathan
authors.forename: T M
authors.initials: TM
authors.lastname: Wah
authors.forename: A
authors.initials: A
authors.lastname: Joyce
authors.forename: H C
authors.initials: HC
authors.lastname: Irving
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003085:Colic / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*