[Structure of the wall of the gastrointestinal tract: a comparative sonographic-morphologic study].

High frequency ultrasound can resolve the structure of the wall of the gastro-intestinal tract into three highly echogenic lines with poorly echogenic zones between them. Sequential removal of layers of the walls of fresh specimens of the gastro-intestinal tract showed the following correlation between the sonographic and histological findings: the innermost and outermost highly echogenic lines correspond to incident and exit echoes. The middle line corresponds with the sub-mucosa and the junctional zones of the mucosa/muscularis mucosa and sub-mucosa/muscularis propria. The intervening low echo lines correspond with the mucosa and muscularis propria.