Diagnostic value of color Doppler twinkling artifact and in urinary calcium stones: an in vitro experiment / 中华超声影像学杂志

ABSTRACT

Objective To investigate the diagnostic value of twinkling artifact in urinary calcium stones.Methods Calcium oxalate monohydrate,hydroxyapatite and whitlockite stone phantoms were prepared and embedded in porcine kidneys for ultrasound scanning.The length and width of twinkling artifact were measured.The intensity of twinkling artifact and the contrast-to-noise ratio (C/N ratio) of acoustic shadowing were recorded and all the data was analyzed statistically.Results All the stone phantoms generated twinkling artifact and acoustic shadowing.The difference of the intensity,length and width of twinkling artifact and the C/N ratio of acoustic shadowing had statistically significant each composition (P ＜0.01).There was no overlap between 95％ confidence interval of the intensity of twinkling artifact for any two compositions,and any two compositions of stones could be differentiated by the intensity of twinkling artifact (P ＜0.05).The C/N ratio of acoustic shadowing of calcium oxalate monohydrate and whitlockite stone phantoms were higher than those of hydroxyapatite ones (P ＜0.05).The receiver operating characteristic (ROC) curve displayed that the cutoff value of 1 127 of the intensity of twinkling artifact could be used to diagnose hydroxyapatite stones.The sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) and area under the curve (AUC) were 74 ％,68 ％,69.8％,72.3％ and 0.743 respectively.Conclusions Twinkling artifact could be used to differentiate the calcium stones,which will be helpful for clinical treatment.