Rectal Cancer

Ultrasound studies show all layers of the rectal wall, represented in the image as 4 hyperechoic and 3 hypoechoic structures (assuming that the layer line between the inner circular and the other longitudinal layers are seen in the muscularis propria).

In the anatomical representation of the recturm on the left , the layers represent:

1. The hyperechoic interface between the waterfilled balloon and the mucosa.
2. The hypoechoic deep mucosa (lamina propria and muscularis mucosae.)
3. The hyperechoic submucosa.
4. The hypoechoic muscularis propria (in some cases seen as 2 layers: inner circular and outer longitudinal layer.)
5. The hyperechoic interface between the rectal wall and the perirectal fat tissue.