Investigating the clinical significance of twinkling artifacts in patients with urolithiasis smaller than 5 mm

Jpn J Radiol. 2014 Aug;32(8):482-6. doi: 10.1007/s11604-014-0337-6. Epub 2014 Jun 7.


Purpose: 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.

Materials and 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.

MeSH terms

  • Adult
  • Aged
  • Artifacts*
  • Female
  • Humans
  • Kidney / diagnostic imaging
  • Male
  • Middle Aged
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*
  • Ultrasonography, Doppler, Color / methods*
  • Ureter / diagnostic imaging
  • Ureteral Calculi / diagnostic imaging
  • Urolithiasis / diagnostic imaging*
  • Young Adult