title: Investigating the clinical significance of twinkling artifacts in patients with urolithiasis smaller than 5 mm.
abstract: OBJECTIVE
  Our aim was to evaluate the effectiveness of twinkling artifacts (TA) in detecting calculi <5 mm in diameter in patients with renal colic pain who had undergone urinary grayscale ultrasonography (US) and computed tomography (CT) imaging assays.
  
  
  METHODS
  In this retrospective study, a total of 76 calculi <5 mm detected in 60 patients were evaluated. Whole data were established using an ultrasound (US) probe at frequencies 1.5-4.5 MHz and noncontrast CT. In US, echogenicity and posterior-shadow (PS) parameters were evaluated and compared with color-Doppler ultrasonography (CDUS) and CT signs.
  
  
  RESULTS
  The mean size of measured calculi was 3.9 ± 0.8 mm (range 2-5 mm). The calculus localization rates detected by CT imaging were as follows: kidneys (n = 61, 80.3 %), proximal ureter (n = 4, 5.3 %), middle ureter (n = 3, 3.9 %) and distal ureter (n = 8, 10.5 %). CT detected the calculus in all 76 cases. There was a statistically significant difference in US-CT and CDUS-CT comparisons (p < 0.001 and p = 0.023, respectively); however, no difference was found when comparing both US methods with CT (p = 0.083).
  
  
  CONCLUSIONS
  TA can be regarded as a significant marker of urolithiasis, and co-operative usage of Doppler and grayscale methods can yield satisfactory results comparable with CT.
authors.affiliation: Department of Radiology, Dumlupinar University Faculty of Medicine, Kutahya, Turkey, drmehmetkorkmaz@gmail.com.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Korkmaz
authors.forename: Bekir
authors.initials: B
authors.lastname: Aras
authors.forename: Bekir
authors.initials: B
authors.lastname: Sanal
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yücel
authors.forename: Serkan
authors.initials: S
authors.lastname: Güneyli
authors.forename: Ahmet
authors.initials: A
authors.lastname: Koçak
authors.forename: Fatih
authors.initials: F
authors.lastname: Uruç
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D014513:Ureter / Q000000981:diagnostic imaging; D014514:Ureteral Calculi / Q000000981:diagnostic imaging; D052878:Urolithiasis / Q000000981:diagnostic imaging*; D055815:Young Adult