Login to Access Video or Poster Abstract: MP81-16
Sources of Funding: None

Introduction

Perineal muscles such as ischiocavernosus (ICM) and bulbospongiosus (BSM) muscles play an important role in male sexual function and a clear understanding of the anatomy of these muscles is critical. However, the anatomical description of ICM and BSM has undergone several revisions (previous conclusions were mostly derived from cadaveric dissection). These findings have been plagued by distortions of anatomical structures in cadavers. Our objective was to elucidate anatomy of the male pelvic/ perineal muscles by resorting to in vivo, proton-density imaging to improve our understanding by avoiding the errors in cadaveric studies. We used proton-density MR images of young adults and performed computer generated, 3-dimensional reconstruction of the male pelvis from these MR images to investigate the anatomy of these perineal muscles pertinent to male sexual function.

Methods

Five male young, normal and healthy subjects, (mean age ~25 yrs) were scanned on a 3T GE MR scanner, using a multi-channel cardiac coil, lying supine, feet-first. Axial morphological proton-density scans were acquired extending from a few slices below the base of the bladder to beyond the entry of the urethra into the penis (~18-22 slices depending on the height of the subject). Discrete anatomical structures, including the pelvic bone, bladder/ urethra, corpus cavernosum (CC), BSM and ICM were segmented from the axial proton density images obtained from these healthy male subjects. Using a volume and surface rendering software (Amira), 3-dimensional models of each structure were generated and assembled into composite figures (all images are color coded so that each colored word identifies with the same structure).

Results

Figure shows important structures of male pelvis. Panels A-D show various structures identified in selected slices that were used to create segmentation and 3D surface rendering. Panel E and F shows 3D reconstruction of important BSM and ISM structures along with the bladder/urethra and bones derived from proton density images

Conclusions

This is perhaps the first 3-D reconstruction based on in-vivo MR images of healthy male perineal muscles. These observations will form the basis of normal perineal muscle morphology that can be monitored in post-surgery patients and correlated with age/ male sexual function.

Funding

None