Fig. 1
Standard application of contrast-enhanced ultrasound scoring system. a Ts 1: the contrast medium enters less than half of the thrombus base, and less than 3 mm in contrast medium width (red arrow); Th 1: no contrast agent was found on the surface of the thrombus. b Ts 2: the contrast medium enters more than half of the thrombus base, but less than 3 mm in contrast medium width (red arrow); Th 2: a small amount of dot-like contrast agent was seen on the surface of the thrombus (yellow arrow). c Ts 3: a wide gap (> 3 mm) of ultrasound contrast agent could be seen in most of the substrate (red arrow); Th 3: strip-like contrast agent was seen on the surface of the thrombus (yellow arrow). d Ts 4: no or narrow/thin substrate (red arrow); Th 4: a large amount of the contrast agent entered the surface of the thrombus (yellow arrow)