The flashlight sign is a recently described B-flow vascular ultrasound sign caused by wall adherent and floating thrombi and emboli in arteries, which appear as bright spots on imaging.
Radiographic features
The flashlight sign is described as a moving, very bright intraluminal focus of signal on B-flow 1.
Practical points
According to the first small scale study the sensitivity of the B-flow flashlight sign exceeds that of contrast enhanced ultrasound and CT angiography in detecting floating intraluminal particles. It is also likely that the presence of such particles signals an increased risk of subsequent downstream embolization, thereby influencing prognosis and management 1.