Ultrasound endoscopy is different from gastroscopy in that gastroscopy can only detect lesions in the mucosal layer, while for submucosal lesions, if the surface of the lesion is very smooth, there is no way for gastroscopy to identify it, and there is no way to perform a biopsy to determine the nature of the lesion. Ultrasound endoscopy is needed to further evaluate the origin and level of the elevated lesion and its echogenic changes, and to determine the nature of the lesion, whether it is a mesenchymal tumor, a smooth muscle tumor, or a lipoma. Ultrasound endoscopy helps guide further treatment, and ultrasound endoscopy is not just for diagnosis, but also for treatment. In the so-called fan-scan ultrasound endoscopy, it is possible to perform interventional treatments such as puncture, drainage, incision, and stent placement under the guidance of the ultrasound probe.