Investigation of choice to know depth of cancer invasion is

The accuracy of T and N stages as determined by CT is less accurate than EUS.EUS (endoscopic ultrasound) is performed using a flexible endoscope with a 7.5-MHz to 12-MHz ultrasound transducer. The stomach is filled with water to distend it and provide an acoustic window, and the stomach wall is visualized as five alternating hypoechoic and hyperechoic layers. The mucosa and submucosa represent the first three layers. The fouh layer is the muscularis propria, the serosa is the fifth layerSabiston 20e pg: 1245