[Nuclear magnetic resonance tomography examinations of the urogenital diaphragm in comparison with corresponding histomorphologic findings (the controversy concerning the musculus transversus perinei profundus)].

Overview

The transversus perinei profundus muscle is a well known structure in found anatomical textbook. Fibers of this muscle are believed to form the so-called external urethral sphincter (musculus sphincter urethrae). Recently histomorphologic investigations have shown that there is no muscular connection between the musculus sphincter urethrae (external sphincter) and the muscle system of the pelvic floor. Furthermore, the external sphincter was found to be divided into parts: the transversely striated part (musculus sphincter urethrae transversostriatus) and the smooth part (musculus sphincter urethrae glaber). Similar to histomorphologic investigations, contrast-enhanced MR imaging has shown the musculus sphincter urethrae to be surrounded by fatty and connective tissue only. Neither in MRI nor in anatomical slices can any connection between the urethral sphincter and the muscle system of the pelvic floor to be found. Thus, on the basis of the results presented in this work it is concluded that the musculus transversus perinei profundus does not exist in the form described in textbooks.