Department of Medical Ultrasound West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China;
Department of Medical Ultrasound West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China;
Department of Medical Ultrasound West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China;
Department of Medical Ultrasound West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China;
Contrast-enhanced ultrasound; Gastrointestinal perforation; Fistula; Abscess; Diagnosis; Case report;