Pudendal Nerve Mapping Towards Improved Neuromodulation for Urinary Retention

Inclusion Criteria: * Clinically referred as having bladder problems that have not responded to conservative treatment. Normal clinical care includes referral to implant of Medtronic Interstim neurostimulator at the pudendal nerve. Fully eligible to receive an Interstim implant. * Adult (18 or older), capable of providing own informed consent and communicating clearly with research team * Capable of speaking, reading, and understanding English, as all study questionnaires are standardized assessments only available in English * Capable of attending all experimental sessions (Visit 1: pre-stage-1 imaging, Visit 2: stage-1 surgery, Visit 3: CT after stage-2 surgery, Visit 3: cystometrogram test) Exclusion * Implanted materials that prohibit magnetic imaging * Any medical problems that prevent an individual from laying flat in an MRI or CT scanner, are are claustrophobic. * Areflexive or atonic bladder * Pregnant or planning to become pregnant. If a woman of child-bearing potential wishes to participate in this study, they will be pre-screened with a test to detect pregnancy. * Diagnosed neurogenic bladder, pudendal nerve damage, lower motor dysfunction, or other conditions that would affect the neural circuits involved in micturition. * Unwilling to allow de-identified data to be stored for future use or shared with other researchers.