Application value of gastric contrast ultrasonography in gastric tumors

In recent years, gastric oral contrast ultrasonography (OCUS) and double contrast-enhanced ultrasonography (DCEUS) have emerged as promising imaging techniques for evaluating gastric tumors, particularly gastric cancer (GC), by providing beneficial insights into tumor morphology, vascular characteristics and response to therapy. OCUS is capable of identifying the thickened gastric wall and lesions by utilizing oral contrast agents. DCEUS, based on OCUS, further employs intravenous contrast-enhanced ultrasound to examine regions of interest, thereby revealing both the anatomical features and perfusion characteristics of the lesions. These two methods are known for being non-irradiating, cost-effective, noninvasive and real-time. With advances in contrast agents and imaging technology, OCUS and DCEUS are expected to become increasingly reliable and contribute to improving patient prognoses. However, the clinical application of these techniques is still evolving, limited by a lack of technical standardization, operator dependence, and inadequate evaluation in certain tumor subtypes and patient populations. This review summarizes the current state in clinical practice of OCUS and DCEUS in the screening, diagnosis, staging and treatment assessment of gastric tumors. It also proposes possible orientations for clinicians to address the identified limitations and improve the clinical value of OCUS and DCEUS, including the integration of artificial intelligence and molecular imaging, alongside establishing international standardization protocols, enhancing physician training systems, and expanding accessibility to primary care settings. Through these efforts, OCUS and DCEUS may become indispensable components of future GC management strategies. CRITICAL RELEVANCE STATEMENT: By summarizing gastric contrast ultrasonography across screening, diagnosis, T staging, N staging and treatment assessment in gastric tumors, and comparing with CT, EUS and endoscopy, this review proposes protocol standardization, operator training and AI-enabled quantification to advance its clinical application. KEY POINTS: Gastric tumors urgently require a simple, inexpensive, noninvasive and easily accessible screening method. Gastric contrast ultrasonography demonstrates utility in detecting and staging gastric tumors. Gastric contrast ultrasonography offers accessible and effective tools for screening of gastric cancer. Accelerating clinical application of gastric contrast ultrasonography demands standardization and technological innovation.