title: Accuracy of ultrasound versus computed tomography urogram in detecting urinary tract calculi.
abstract: OBJECTIVE
  To determine the (i) sensitivity and specificity of ultrasound (USG) in the detection of urinary tract calculi, (ii) size of renal calculi detected on USG, and (iii) size of renal calculi not seen on USG but detected on computed tomography urogram (CTU).
  
  
  METHODS
  A total of 201 patients' USG and CTU were compared retrospectively for the presence of calculi. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of USG were calculated with CTU as the gold standard.
  
  
  RESULTS
  From the 201 sets of data collected, 59 calculi were detected on both USG and CTU. The sensitivity and specificity of renal calculi detection on USG were 53% and 85% respectively. The mean size of the renal calculus detected on USG was 7.6 mm ± 4.1 mm and the mean size of the renal calculus not visualised on USG but detected on CTU was 4 mm ± 2.4 mm. The sensitivity and specificity of ureteric calculi detection on USG were 12% and 97% respectively. The sensitivity and specificity of urinary bladder calculi detection on USG were 20% and 100% respectively.
  
  
  CONCLUSIONS
  This study showed that the accuracy of US in detecting renal, ureteric and urinary bladder calculi were 67%, 80% and 98% respectively.
authors.affiliation: Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Faculty of Medicine, Dept of Radiology, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia. ericayeehing@yahoo.com.
authors.forename: B
authors.initials: B
authors.lastname: Salinawati
authors.affiliation: Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Faculty of Medicine, Dept of Radiology, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia.
authors.forename: E Y
authors.initials: EY
authors.lastname: Hing
authors.affiliation: Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Faculty of Medicine, Dept of Surgery, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia.
authors.forename: X I
authors.initials: XI
authors.lastname: Fam
authors.affiliation: Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Faculty of Medicine, Dept of Surgery, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia.
authors.forename: M A
authors.initials: MA
authors.lastname: Zulfiqar