Perineal body anatomy in living women: 3-dimensional analysis using thin-slice magnetic resonance imaging

Abstract

The objective of the study was to describe a framework for visualizing the perineal body's complex anatomy using thin-slice magnetic resonance (MR) imaging. Two millimeter thick MR images were acquired in 11 women with normal pelvic support and no incontinence/prolapse symptoms. Anatomic structures were analyzed in axial, sagittal, and coronal slices. Three-dimensional (3-D) models were generated from these images. Three distinct perineal body regions are visible on MR imaging: (1) a superficial region at the level of the vestibular bulb, (2) a midregion at the proximal end of the superficial transverse perineal muscle, and (3) a deep region at the level of the midurethra and puborectalis muscle. Structures are best visualized on axial scans, whereas craniocaudal relationships are appreciated on sagittal scans. The 3-D model further clarifies interrelationships. Advances in MR technology allow visualization of perineal body anatomy in living women and development of 3-D models that enhance our understanding of its 3 different regions: superficial, mid, and deep.