title: Differentiation of ureteral stones and phleboliths using Hounsfield units on computerized tomography: a new method without observer bias.
abstract: To differentiate ureteral stones and phleboliths by measuring density [as Hounsfield unit (HU)] and volume (as mm3) of the opacities in the bony pelvis on unenhanced computerized tomography (U-CT). A total of 52 patients, who underwent semirigid ureteroscopy and laser lithotripsy for distal ureteral stone and had isochoronous phleboliths in U-CT, were included. Images were reviewed for density and volume of the opacities. Data were compared, and a cut-off value was defined with receiver operating characteristics curve analysis to differentiate the nature of the opacity. Using the cut-off values of 171 mm³ for volume (sensitivity 75 %, specificity 100 %) and 643 HU for density (sensitivity 75 %, specificity 93 %), differentiation between stone and phlebolith was achieved. Differentiation of pelvic opacities needs meticulous observation with certain signs on U-CT. On the other hand, our study offers a new method, with certain cut-off values, such as 643 HU and 171 mm3, which can be used to precisely predict the actual nature of opacities of interest.
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey. yiloren@yahoo.com.|Marmara Universitesi Pendik Egitim ve Arastırma Hastanesi, Fevzi Cakmak Mah., Mimar Sinan Cad. 41, Ust Kaynarca, Pendik, 34899, Istanbul, Turkey. yiloren@yahoo.com.
authors.forename: Yiloren
authors.initials: Y
authors.lastname: Tanidir
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Sahan
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Mehmet Kazim
authors.initials: MK
authors.lastname: Asutay
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Tarik Emre
authors.initials: TE
authors.lastname: Sener
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Farhad
authors.initials: F
authors.lastname: Talibzade
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Asgar
authors.initials: A
authors.lastname: Garayev
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Ilker
authors.initials: I
authors.lastname: Tinay
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Cagri Akin
authors.initials: CA
authors.lastname: Sekerci
authors.affiliation: Department of Urology, School of Medicine, Marmara University, Istanbul, Turkey.
authors.forename: Ferruh
authors.initials: F
authors.lastname: Simsek
mesh_terms: D016022:Case-Control Studies; D003937:Diagnosis, Differential; D006801:Humans; D017602:Lithotripsy, Laser; D015588:Observer Variation; D010388:Pelvis / Q000000981:diagnostic imaging; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014514:Ureteral Calculi / Q000000981:diagnostic imaging* / Q000628:therapy*; D018666:Ureteroscopy; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
keywords: Diagnosis; Hounsfield unit; Imaging; Ureteral stones; Ureteroscopy