1. ¹Department of Urology, University of Washington, Seattle, WA, USA
2. ²Department of Radiology, University of Washington, Seattle, WA, USA
3. ³Kinsey Institute, Bloomington, IN, USA
4. ⁴Department of Psychiatry, University of Washington, Seattle, WA, USA
5. ⁵Pfizer, Inc., Groton, CT, USA

Correspondence: Dr KR Maravilla, Department of Radiology, University of Washington, 1959 NE Pacific, Box 357115, Seattle, WA 98195, USA. E-mail: kmarav@u.washington.edu

Received 22 April 2007; Revised 1 November 2007; Accepted 2 November 2007; Published online 6 December 2007.

Abstract

The purpose of this study was to determine if magnetic resonance imaging (MRI) could quantify a difference in clitoral response following administration of a vasoactive medication, in 12 women with female sexual arousal disorder (FSAD). Subjects were entered into a double-blind, randomized two-way crossover study of sildenafil 50 mg vs placebo administered 1 h prior to genital MRI. Each subject underwent two MR studies, performed while subjects viewed alternating segments of nonerotic and erotic video. MR images were analyzed for change in clitoral volume during each session. The mean change in clitoral volume for the entire group was higher in the sildenafil MRI session (1282 mm³) compared with placebo (849 mm³) but did not reach statistical significance (P=0.064). Comparison using analysis of variance between the two sessions for each individual subject revealed a significant increase in clitoral volume following sildenafil compared with placebo in 6 of 12 subjects, no significant change in either imaging session in three subjects and in three subjects, there was a robust clitoral response in both MR sessions. In conclusion, MR measurements of clitoral volume can provide an objective measure of engorgement change following a vasoactive medication in women with FSAD.