Magnetic resonance imaging anatomy of the female genitalia in premenopausal and postmenopausal women.

PURPOSE: We used contrast enhanced magnetic resonance imaging (MRI) of the female genital organs to describe normal anatomy and differences between premenopausal and postmenopausal women. MATERIALS AND METHODS: A total of 12 healthy premenopausal and 9 healthy postmenopausal women underwent MRI. A 1.5 Tesla system with phased array coils anterior and posterior to the pelvis was used to produce T1-weighted images before and after intravenous administration of MS-325 (Epix Medical, Cambridge, Massachusetts), a new gadolinium based blood pool contrast agent. Select structural dimensions were measured for reference. RESULTS: The clitoris and vestibular bulbs were well delineated on T1-weighted post-contrast images. The clitoral unit formed a brightly enhancing, wishbone-shaped structure lying just anterior to the inverted V of the bulbs, which surrounded the urethra and vagina. The urethral complex had a target-like appearance with layers that were discernible on T1 post-contrast images. The urethra, vagina and rectum formed a distinct complex within uniformly enhancing soft tissue. The vagina was well visualized in premenopausal subjects but without distinguishable mucosal rugae or clearly separate layers in postmenopausal subjects. Postmenopausal subjects were also observed to have smaller labia minora width, vestibular bulb width, vaginal width and wall thickness, and cervical diameter. Pelvic and genital structures were not well visualized on T1 noncontrast images. CONCLUSIONS: To our knowledge we describe detailed female genital anatomy for the first time using MRI with MS-325 contrast medium. The clitoris, vestibular bulbs, labia majora and minora, urethra, vagina, cervix and rectum are well visualized on T1 post-contrast images. The observed genital anatomy on MRI was consistent with descriptions in current anatomical texts. Differences in the female genitalia between premenopausal and postmenopausal women were discernible on MRI. These data are important for future studies using MRI for evaluating anatomical anomalies, postoperative changes and female sexual function.

Nocturnal penile tumescence and effects of complete spinal cord injury: possible physiologic mechanisms.

OBJECTIVES: To determine the role of the spinal cord in the initiation and/or modulation of nocturnal erectile activity, we measured nocturnal penile tumescence (NPT) in men with complete spinal cord injuries at known locations. METHODS: Eighteen men between the ages of 27 and 57 years (mean 45) with known complete spinal cord lesions and no history of other medical problems adversely affecting erectile function completed International Index of Erectile Function questionnaires and underwent RigiScan testing for two consecutive nights. RigiScan tracings were evaluated for the presence and quality of NPT activity. Erectile episodes lasting longer than 10 minutes with base and tip rigidity greater than 70% were designated "good"; the remainder were designated "borderline," "poor," or "absent." RESULTS: Of 9 men with cervical injuries and 9 with thoracic injuries, 8 and 3, respectively, had evidence of NPT. Of the 9 men with cervical injuries, 3 had one or more "good" nocturnal erections, and 1 of 9 men with thoracic injuries had one or more "good" nocturnal erections. The mean duration of the single longest erectile event was 26 minutes in men with cervical spinal injuries and 12 minutes in men with thoracic spinal injuries. Men with cervical and thoracic injuries had a mean overall International Index of Erectile Function score of 10 and 16 and a mean erectile domain score of 2 and 3, respectively. CONCLUSIONS: Spinal regulation is critical for nocturnal erectile activity, and the isolated thoracic cord is less effective than the isolated cervical cord in maintaining NPT. Despite the presence of nocturnal erectile activity, volitional erectile function in spinal cord-injured men is significantly impaired.