High-frame-rate contrast-enhanced ultrasound findings of liver metastasis of duodenal gastrointestinal stromal tumor: A case report and literature review

Figure 2 High-frame-rate contrast-enhanced ultrasound findings. Images showing high-frame-rate contrast-enhanced ultrasound perfusion patterns corresponding to those in contrast-enhanced ultrasound images. Concentric enhancement was more obvious. Irregular vessel column and rim enhancement can be seen (white arrows). A: Conventional ultrasound showing an uneven hypo-echo lesion with an approximate size of 3.5 cm × 2.2 cm × 2.4 cm and a peripheral hypoechoic halo located in the left lobe of the liver; B: Color Doppler flow imaging showing the dot-linear blood flow signal within the lesion; C-E: Contrast-enhanced ultrasound findings; F: The lesion showed heterogeneous hyper-enhancement at peak; G-J: We could not find obvious concentric and rim enhancement on contrast-enhanced ultrasound.