Related Experiment Videos
Multiplanar anal endosonography--normal anal canal anatomy
A B Williams1, C I Bartram, S Halligan
1Department of Intestinal Imaging, St. Mark's Hospital, Northwick Park, Harrow, UK.
Summary
Three-dimensional anal endosonography reveals significant gender differences in anal canal anatomy, particularly in the external anal sphincter length and angle. This study details the normal multiplanar ultrasonic appearance of the anal canal.
Area of Science:
- Anorectal imaging
- Medical ultrasound
- Anatomical studies
Background:
- Volume acquisition in anal ultrasound allows for multiplanar imaging of the anal canal.
- The normal multiplanar ultrasonic appearance of the anal canal is described.
- Gender differences in anal canal anatomy are highlighted.
Purpose of the Study:
- To describe the normal multiplanar ultrasonic appearance of the anal canal.
- To identify and highlight gender differences in anal canal anatomy using three-dimensional anal endosonography.
Main Methods:
- Ten males and 12 females underwent three-dimensional anal endosonography (3-D AES).
- Volume datasets were seeded in the axial plane for multiplanar anatomical identification.
- Measurements of the external anal sphincter and puborectalis were taken.
Main Results:
- The anterior external anal sphincter (EAS) was significantly longer in men (30.1 mm) than women (16.9 mm).
- The angle formed by the anterior EAS and the anal canal axis was more acute in men (11.1 degrees) than women (18.6 degrees).
- No significant gender difference was found in puborectalis length.
Conclusions:
- Multiplanar anal endosonography (AES) allows for detailed longitudinal measurement of anal canal components.
- Important gender differences in anal canal anatomy have been revealed.
- The multiplanar ultrasonic appearance of the normal anal canal has been described for the first time.