Sagittal T1-weighted MRI shows a hypointense lesion in the deep postanal space (red arrows)

Copyright information:Taken from "Fistulotomy and drainage of deep postanal space abscess in the treatment of posterior horseshoe fistula"BMC Surgery 2003;3():10-10.Published online 26 Nov 2003PMCID:PMC317325.Copyright © 2003 Inceoglu and Gencosmanoglu; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. Note that the lesion is located under the levator ani muscle (yellow arrows), which indicates that it is in the deep postanal space.