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Whang, Ahn, Sung, Park, Kim, Cho, and Lee: Female External Genitalia and Urethra on MR Imaging: Optimal Pulse Sequence and Comparison of Anatomy in Premenopausal and Postmenopausal Women
Original Article
Journal of the Korean Society of Magnetic Resonance in Medicine

Journal of the Korean Society of Magnetic Resonance in Medicine 2011; 15(2): 146-153.

Published online: 31 August 2011

DOI: https://doi.org/10.13104/jksmrm.2011.15.2.146

Female External Genitalia and Urethra on MR Imaging: Optimal Pulse Sequence and Comparison of Anatomy in Premenopausal and Postmenopausal Women

Shin Young Whang, Kyung-Sik Ahn, Deuk Jae Sung, Beom Jin Park, Min Ju Kim, Sung Bum Cho, Nam Joon Lee

Department of Radiology, Anam Hospital, College of Medicine, Korea University, Korea.

Corresponding author: Kyung-Sik Ahn, M.D., Department of Radiology, Anam Hospital, College of Medicine, Korea University #126-1, 5-Ka Anam-dong, Sungbuk-gu, Seoul 136-075, Korea. Tel. 82-2-920-5567, Fax. 82-2-929-3796, glassesik@gmail.com

Received 5 July 2011       Revised 26 July 2011       Accepted 4 August 2011

Copyright © 2011 Korean Society of Magnetic Resonance in Medicine

(open-access):

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To describe normal anatomy and compare the differences of external genital organs and urethra on MR imaging in pre- and postmenopausal women.

Materials and Methods

A total of 19 pre- and 18 postmenopausal healthy women underwent pelvis MR imaging at 1.5 T. Two radiologists retrospectively scored and compared the image quality of female external genitalia and urethra on axial T2-weighted images (T2WI) and axial fat-suppressed contrast-enhanced T1-weighted images (FSCE-T1WI) by using Wilcoxon signed ranks test. The radiologists compared the wall thickness or size of external genital organs and urethra on FSCE-T1WI between two groups by using Student t test.

Results

Image quality was better with FSCE-T1WI than with T2WI in all subjects (p < 0.05). The vestibular bulb, clitoris and labium minor were more clearly visualized on FSCE-T1WI in premenopausal subjects rather than in postmenopausal subjects (p < 0.05). The urethra had a target-like appearance with three layers in premenopausal and postmenopausal subjects. Postmenopausal subjects were observed to have significantly smaller vaginal wall thickness, urethral wall thickness and vestibular bulb width than premenopausal subjects (p < 0.05).

Conclusion

The anatomy and morphologic changes of female external genital organs and urethra were well discernible on FSCE-T1WI.

Keywords: Magnetic resonance imaging (MRI), Anatomy, Genitalia, Female

Figures and Tables

Fig. 1
Fat-suppressed contrast-enhanced axial T1 weighted (a-c) and T2-weighted (d-f) MR images of genitalia in a premenopausal subject. All genital structures were delineated more clearly on fat-suppressed contrast-enhanced axial T1-weighted image. Cc, clitoral crus. Ch, clitoral hood. Cg, clitoral glans. Lm, labia minora. U, urethra. V, Vagina. Vb, Vestibular bulb.
jksmrm-15-146-g001
Fig. 2
Fat-suppressed contrast-enhanced T1 weighted images at pubic symphysis level in premenopausal (a) and postmenopausal (b) subjects. The separate three layers of vaginal wall are well visualized in a premenopausal subject but not clearly defined in a postmenopausal subject.
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Fig. 3
Fat-suppressed contrast-enhanced T1 weighted images at ischial tuberosity level in premenopausal (a) and postmenopausal (b) subjects. The clitoral crura (straight arrow) are well delineated as a wishbone-shaped structure surrounding the urethra and vagina. The vestibular bulb (curved arrow) is paramedian in location and lying just posterior to the clitoral crura. The vestibular bulb and clitoral crura are more clearly visualized in a premenopausal subject rather than in a postmenopausal subject.
jksmrm-15-146-g003
Fig. 4
Fat-suppressed contrast-enhanced T1 weighted images at vaginal introitus level in premenopausal (a) and postmenopausal (b) subjects. The clitoral glans (arrow) and labium minora are more clearly visualized in a premenopausal subject rather than in a postmenopausal subject. The anterior borders of labium minora form the clitoral hood which covers the clitoral glans.
jksmrm-15-146-g004
Table 1
Comparison of Image Qualities by the Scores Using the Both Sequences
jksmrm-15-146-i001

Numbers: Average values ± standard deviation

T2WI: T2-weighted images

FSCE-T1WI: Fat-suppressed contrast-enhanced T1-weighted images

Table 2
Comparison of Image Qualities by the Scores Using FSCE-T1WI in Premenopausal and Postmenopausal Subjects
jksmrm-15-146-i002

Numbers: Average values ± standard deviation

FSCE-T1WI: Fat-suppressed contrast-enhanced T1-weighted images

Table 3
Anatomical Measurements of Premenopausal and Postmenopausal Subjects
jksmrm-15-146-i003

Numbers: Average values ± standard deviation

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