"The presence of a renal twinkling artifact on sonography has a true positive and false positive rates of about 50% for the presence of nephrolithiasis on unenhanced CT; it therefore has questionable clinical value10."
"colour velocity scale of at least 60 cm/s is recommended to reduce intrarenal arterial aliasing; PRF has not been shown to reliably alter the presence of the twinkling artifact 9,12, whereas colour gain does influence its appearance 8"
"The presence of a renal twinkling artifact on sonography has a true positive and false positive rates of about 50% for the presence of nephrolithiasis on unenhanced CT; it therefore has questionable clinical value10."