[Twinkling artifact in color Doppler ultrasonography: pictorial essay].

The "twinkling" artifact is a color-flow sonographic artifact presenting as a rapidly changing color encoding behind a strongly reflecting structure. Recently, "twinkling" artifact has been described behind calcifications in various tissues, urinary and gallbladder stones, encrustated indwelling ureteral stents, strongly reflecting orbital structures and an intracranial microcoil. It is important to recognize this artifact as it could lead to misdiagnosis of vascular flow within a tissue. "Twinkling" artifact could be considered as an additional sonographic feature in the diagnosis of urinary and bile duct stones and encrustated indwelling ureteral stents. "Twinkling" artifact could also play a role in detecting the morphology or biochemical composition of urinary stones.