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

Figure 1 Magnetic resonance imaging findings. The lesion is approximately 2.3 cm in the left external lobe. A: T1-weighted image of the nodule showing hypo-intensity; B T2-weighted image of the tumor showing higher intensity; C: Diffusion-weighted image of the tumor showing a higher intensity; D: The lesion presented edge enhancement after reinforcement (white arrows).

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.

Figure 3 Contrast-enhanced ultrasound quantitative analysis results. A-C: Contrast-enhanced ultrasound quantitative analysis showed ΔPI of 3.58 dB at peak; D-F: High-frame-rate contrast-enhanced ultrasound quantitative analysis showed ΔPI of 6.63 dB at peak.

Figure 4 Histopathology findings. A: Microscopy showed a patchy distribution of short and spindle cells (H&E staining, × 200); B-D: Immunohistochemical staining displayed CD117 (+), Dog-1 (+), and Vimentin (+) (H&E staining, × 200).

Figure 5 DNA sequencing electropherograms. DNA sequencing electropherograms revealed c-Kit 11 (c.1655_1699del 15 type), c-Kit 9, c-Kit 13, c-Kit 17, PDGFRα12, and PDGFRα18 wild type mutations.