1. A method for evaluating the behavior and performance of a tampon in vivo, said method comprising the steps of: creating a database populated with information associated to a study of the performance of a tampon; qualifying one or more candidates as participants in said study for evaluating the performance of said tampon in vivo by subjecting said candidates to an evaluation process that determines the ability of said candidates to safely participate in said study and obtains consent from said candidates regarding said participation; determining detailed protocols and Magnetic Resonance Imaging (MRI) parameter settings relevant to said candidates and said study; providing an MRI operable in accordance with said protocols and MRI parameter settings and using said MRI to conduct one or more scans of each candidate; qualitatively analyzing said MRI scans with a computer having image analysis software, comprising at least one of a step of identifying anatomical structures proximate said tampon in said participant; observing said tampon over time; observing said tampon's influence on a vaginal wall of said participant; determining movement of said tampon within said participant; determining how a specific disease state influences tampon performance; and determining an indication of fluid absorption of said tampon; quantitatively analyzing at least a portion of said MRI scans by determining physical characteristics of said anatomical structures and tampons using a computer having image analysis software and data analysis and statistical software packages; at least one of said qualitative analysis and said quantitative analysis being performed using said software program; populating said database with information indicative of said quantitative and qualitative analyses; and wherein said participant is scheduled for MRI scanning more than once during her menstrual cycle and said participant is wearing a different tampon each time said participant is scheduled for an MRI scanning.