| Layer echogenicity | Anatomic structure |
| Lumen | Echo-poor (fluid)/echo-rich (air) depending on content |
| Luminal echo-rich layer | Echo-line between lumen and mucosa |
| Luminal echo-poor layer | Mucosa |
| Echo-rich layer | Submucosa |
| Echo-poor layer | Muscularis propria |
| Echo-rich layer | Serosa |
