Clinical Significance of Twinkling Artifact in the Diagnosis of Urinary Stones

Ultrasound-guided extracorporeal shock wave lithotripsy with minimal x-ray exposure prevented genitourinary tract injury patients with urolithiasis in Taiwan

BACKGROUND

This study investigated the use of ultrasound-guided extracorporeal shock wave lithotripsy (ESWL) to break stones in the genitourinary tract and prevent genitourinary injury. Our goals were to achieve accurate focusing and minimal X-ray exposure for the benefit of the patients.

METHODS

The LiteMed LM-9200 lithotripter with ultrasonography and fluoroscopy was used for two different procedures: autoaimed and autoperiodical. These procedures enabled dual focusing on stone localization and tracking.

RESULTS

Out of 108 patients who underwent autoperiodical procedures, 29 had no gross hematuria. Among the 335 patients who received autoaimed procedures, 194 had no gross hematuria. The average duration of X-ray exposure during autoperiodical and autoaimed procedures was 120 and 50 s, respectively.

CONCLUSION

The ultrasound-guided ESWL with minimal X-ray exposure was found to be useful in treating genitourinary upper-tract urolithiasis in the autoaimed procedure. Patients who underwent the autoaimed procedure experienced less gross hematuria compared to those who underwent the autoperiodical procedure.

Diagnostic accuracy of Doppler twinkling artifact for identifying urolithiasis: a systematic review and meta-analysis

OBJECTIVE

The goal of this study was to perform a comprehensive meta-analysis to assess the overall diagnostic value of Doppler twinkling for the diagnosis of urolithiasis.

METHODS

We systematically searched the PubMed, EMBASE, and Cochrane Library databases from inception through May 31, 2021. Studies including patients with urolithiasis who underwent color flow Doppler sampling to highlight the twinkling artifact and computed tomography were included. Diagnostic test meta-analysis was performed with a bivariate model. We used summary receiver operating characteristic curves to summarize the overall diagnostic performance. The weighted sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were calculated.

RESULTS

Sixteen studies involving 4572 patients were included in the systematic review and meta-analysis. The weighted sensitivity was 0.86 (95% confidence interval [CI] 0.72-0.94), specificity 0.92 (95% CI 0.75-0.98), positive likelihood ratio 11.3, negative likelihood ratio 0.2, and diagnostic odds ratio 75.5.

CONCLUSION

The Doppler twinkling artifact has good diagnostic value for the diagnosis of urolithiasis and should be used as a complementary tool in the diagnosis of urolithiasis.

Does twinkle artifact truly represent a kidney stone on renal ultrasound?

INTRODUCTION

Nephrolithiasis is detected on ultrasound by the presence of an echogenic focus, posterior acoustic shadowing and/or twinkle artifact (TA). TA has been shown to be highly predictive of nephrolithiasis in adults with renal colic and ureteral stones. We sought to evaluate if TA is reliable for diagnosing nephrolithiasis in the pediatric population.

METHODS

We reviewed renal ultrasound reports indicating presence or absence of TA associated with a single echogenic focus in the kidney or ureter. Exclusion criteria were age >18, multiple echogenic foci or medullary calcinosis, no follow-up, or TA located outside the kidney or ureter. Stone was confirmed either by CT within 3 months of color Doppler ultrasound, visualization on ureteroscopy, or patient report of passing the stone.

RESULTS

Five hundred and ninety-nine ultrasound reports were reviewed and 293 met inclusion criteria. Sixty-nine had diffuse twinkle without echogenic focus and 224 showed TA with single echogenic focus. 135 patients had confirmatory information available (Summary Table). Nephrolithiasis was diagnosed using TA and confirmed on confirmatory studies for 49 ultrasounds. The majority of confirmed stones were in the kidney (n = 40; 82%) and mean size of confirmed stones on ultrasound was 5 mm (range 1.5-10). Sensitivity, specificity, positive predictive value and negative predictive value of TA for detecting nephrolithiasis were 83%, 78%, 74% and 86% respectively.

CONCLUSIONS

Compared to the adult literature, TA in children has lower sensitivity, specificity and positive predictive value, but similar negative predictive value for diagnosing nephrolithiasis. This may be related to renal location and smaller stone size. The presence of TA should be weighed in the setting of other clinical and radiographic evidence of nephrolithiasis.

Sonography and Test-Feeding in the Diagnosis of Infantile Hypertrophic Pyloric Stenosis

Objective:

To determine the use of sonography and test-feeding in the diagnosis of infantile hypertrophic pyloric stenosis (IHPS).

Methodology:

A total of 79 infants from 2 weeks up to 12 weeks presenting with clinical signs (projectile vomiting) of IHPS were included in the study while sent to sonography. The study duration was February 2014 to December 2019.

Results:

The mean age of patients was 5.18 ± 2.69 weeks ranging from 1 to 12 weeks. Male gender was predominant with 62 (78.5%) cases. Of the total 79 cases, 36 (54.6%) were suggested as positive cases of IHPS and 43 (54.4%) were as normal with sonography. Most of the cases of IHPS (23; 29.1%) were observed in firstborn babies. Mean pyloric length in normal and IHPS was 12.69 ± 0.87 and 20.78 ± 2.28 mm, respectively, and mean pyloric muscle thickness in the normal and IHPS was 2.24 ± 0.36 and 5.27 ± 0.82 mm, respectively, while mean pyloric diameter in normal and IHPS was 12.69 ±0.87 and 15.01± 2.52 mm, respectively.

Conclusion:

The reliability of sonographic findings was better than test-feeding in the diagnosis of IHPS. Male infants, in this cohort, were five times more susceptible to develop IHPS, compared with females.