Ligang Cui is a Professor, Chief Physician, and the Director of Ultrasound Department at Peking University Third Hospital. His research focuses on clinical applications of novel ultrasound technologies, including: 1) Utilizing macrophage-specific ultrasound contrast agents to optimize sentinel lymph node biopsy procedures in breast cancer, reducing false-negative rates and improving postoperative survival rates; 2) Applying ultrasound elastography combined with biomechanical modeling to construct muscle length-Young's modulus curves, extracting intrinsic tissue parameters for enhanced diagnosis of musculoskeletal disorders; 3) Developing targeted porphyrin microbubbles for HER2-positive gastric cancer therapy, achieving dual-targeted drug delivery through antibody conjugation and ultrasound-mediated cavitation, which increases sonosensitizer concentration in tumor tissue while reducing systemic toxicity.