Role of ultrasound in colorectal diseases

Table 1 Ultrasonic features of the gut wall: Five concentric ring with alternating echogenicity can be distinguished by ultrasound examination the rings correspond to the histological layers of the gut wall

Echogenicity	Anatomic structure
Central area with variable echogenicity (fluid - hypoechoic; gas - echogenic)	Bowel lumen
Echogenic layer	Interface between the bowel lumen and mucosa
Hypoechoic layer	Mucosa/muscularis mucosae
Echogenic layer	Submucosa
Hypoechoic layer	Muscularis propria
Echogenic layer	Interface between adventitia/serosa and surrounding structures