Distribution of topical medication in the human vagina as imaged by magnetic resonance imaging

Objective: To assess the use of magnetic resonance imaging (MRI) to determine the varying distribution of a vaginally placed gel over time and with different levels of patient activity. Design: Prospectives interventional trial. Setting: University medical center. Patient(s): One nulliparous volunteer with normal menstrual cycles and no gynecologic disease who underwent seven MRI scans of the pelvis. Intervention(s): Five mt of a commercially available topical spermicide was mixed with gadolinium-chelate magnetic resonance contrast material and introduced with a standard applicator. T1-weighted three-dimensional MRI was done to assess the distribution of the gel. Main Outcome Measure(s): Gel thickness and distribution. Result(s): The initial bolus of gel was delivered into the upper portion of the vagina, above the urogenital diaphragm. Thereafter, it spread into the vaginal fornices and "flattened" to cover the lateral aspects of the vagina. Without ambulation, the majority of spread was confined to the upper vagina. With ambulation and longer elapsed time, the gel spread further in the upper vagina and into the lower vagina, and significant vaginal surface coverage increased significantly. Conclusion(s): Magnetic resonance imaging can be used to monitor the spread of vaginally placed products and to evaluate coverage of topical drugs used for prevention and treatment, including those used for HIV prophylaxis.