title: A new method for computer-assisted detection, definition and differentiation of the urinary calculi.
abstract: OBJECTIVE
  Urinary stones are common and can be diagnosed with computed tomography (CT) easily. In this study, we aimed to specify the opacity characteristics of various types of calcified foci that develop through the urinary system by using an image analysis program. With this method, we try to differentiate the calculi from the non-calculous opacities and also we aimed to present how to identify the characteristic features of renal and ureteral calcules.
  
  
  METHODS
  We obtained the CT studies of the subjects (n = 48, mean age = 41 years) by using a dual source CT imaging system. We grouped the calculi detected in the dual-energy CT sections as renal (n = 40) or ureteric (n = 45) based on their locations. Other radio-opaque structures that were identified outside but within close proximity of the urinary tract were recorded as calculi "mimickers". We used ImageJ program for morphological analysis. All the acquired data were analyzed statistically.
  
  
  RESULTS
  According to thorough morphological parameters, there were statistically significant differences in the angle and Feret angle values between calculi and mimickers (p < 0.001). Multivariate logistical regression analysis showed that Minor Axis and Feret angle parameters can be used to distinguish between ureteric (p = 0.003) and kidney (p = 0.001) stones.
  
  
  CONCLUSIONS
  Computer-based morphologic parameters can be used simply to differentiate between calcular and noncalcular densities on CT and also between renal and ureteric stones.
authors.affiliation: Department of Radiology, Centermed Advanced Imaging Center , Istanbul , Turkey .
authors.forename: Duzgun
authors.initials: D
authors.lastname: Yildirim
authors.forename: Ovunc
authors.initials: O
authors.lastname: Ozturk
authors.forename: Onur
authors.initials: O
authors.lastname: Tutar
authors.forename: Fuad
authors.initials: F
authors.lastname: Nurili
authors.forename: Halil
authors.initials: H
authors.lastname: Bozkurt
authors.forename: Huseyin
authors.initials: H
authors.lastname: Kayadibi
authors.forename: Ercan
authors.initials: E
authors.lastname: Karaarslan
authors.forename: Selim
authors.initials: S
authors.lastname: Bakan
mesh_terms: D000328:Adult; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014514:Ureteral Calculi / Q000175:diagnosis*
keywords: Computed tomography; differential diagnosis; differentiation; ureter; urinary calculi