J Korean Radiol Soc.  2002 Feb;46(2):163-169. 10.3348/jkrs.2002.46.2.163.

Comparison of Surface and Saddle Endoanal Coil to Evaluate anal Sphincter in Infants and Young Children: Experimental Study Using Phantom and Cats

• Kim HS
• Kim MJ
• Kim EJ
• Suh JS
• Kim MJ
• Jeong EK

• KMID: 1832981
• DOI: http://doi.org/10.3348/jkrs.2002.46.2.163

Abstract

PURPOSE
We designed an inside-out-type endoanal surface and saddle coil to evaluate the anal sphincter of young children who have difficulty in controlling defecation after the correction of anorectal malformation, and compared two coils using an imaging phantom and cats.
MATERIALS AND METHODS
Using two coils, T1- and T2-weighted axial and coronal images of the phantom and of the anorectal region of cats were obtained, and the results were compared in terms of changes in signal intensity and SNR according to the distance from the coil's surface. We also compared the capability of the coils to delineate the internal and external anal sphincter of cat anorectum, both of which are important in the control of defecation.
RESULTS
The saddle coil was slightly superior to the surface coil in terms of SNR, but inferior in terms of the signal intensity of the region of interest of the cat's anorectum. Moreover, artifacts of low signal intensity appeared in an azimuthal direction on axial images acquired using the saddle coil and prohibited delineation of the whole of the anal sphincter. In terms of image quality, the surface coil was therefore superior to the saddle coil.
CONCLUSION
Our findings suggest that among inside-out-type endoanal coils, the surface coil may be superior to the saddle coil in MR imaging to evaluate the anal sphincter of young children.

Keyword

Anus, imperforate; Anus, MR; Magnetic resonance (MR), coil arrays; Magnetic resonance (MR), in infants and children; Magnetic resonance (MR), surface coils

MeSH Terms

Anal Canal*
Animals
Anus, Imperforate
Artifacts
Cats*
Child*
Defecation
Humans
Infant*
Magnetic Resonance Imaging
Phantoms, Imaging