Related Experiment Video
Updated: Jun 7, 2026

Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse
Published on: April 17, 2019
Perineal body anatomy in living women: 3-dimensional analysis using thin-slice magnetic resonance imaging
Kindra A Larson1, Aisha Yousuf, Christina Lewicky-Gaupp
1Pelvic Floor Research Group and Division of Gynecology, Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
Objective:
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.
Study Design:
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.
Results:
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.
Conclusion:
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.
Related Concept Videos
Muscles of the Pelvic Floor and Perineum
Perineal Layer
The perineum is a diamond-shaped area below the pelvic diaphragm, divided into an anterior urogenital triangle that contains the external genitals and a posterior anal triangle housing the anus. The urogenital...
Magnetic Resonance Imaging
Imaging Studies IV: Magnetic Resonance Imaging

