Phenotyping Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) by Intravesical Contrast Enhanced - Magnetic Resonance Imaging (ICE-MRI) Bladder Permeability Assay

Inclusion Criteria: 18-80 years old subjects from both genders and an IC/BPS diagnosis with a cystoscopic finding of Hunner lesions or absence and also have the following: Pain (suprapubic, pelvic, urethral, vaginal or perineal) associated with bladder storage symptoms and pain on bladder filling that is relieved upon emptying Urgency or nocturia (average of >1 nocturnal void over 3 consecutive days on bladder diary). The O'Leary-Sant Interstitial cystitis symptom index (ICSI) and Interstitial cystitis problem index (ICPI) are valid and reliable measures of IC/BPS symptoms, and only IC/BPS patients with scores of ICSI of > 9 and an ICPI > 8 will be recruited. Age matched controls with no abnormal cystoscopic findings and with no bladder storage symptoms will be recruited. Exclusion Criteria: Patients with urinary incontinence, suspicion for UTI on urine dipstick, history of recurrent UTIs, or history of spinal cord injury. Notwithstanding the fact that chronic bladder inflammation of IC/BPS patients evokes higher bladder permeability to instilled radiolabeled sodium chloride than acute inflammation of UTI patients, the investigators plan to exclude patients with UTIs as a confounding factor to rigorously establish the link between Hunner lesion and bladder permeability. Patients with current diagnosis or previous history of urologic malignancy, prior bladder augmentation surgery, pelvic radiation, serum creatinine >1.5mg/dl, diabetes mellitus, untreated hypertension, and proteinuria. Participants in whom magnetic resonance imaging (MRI) is contraindicated including, but not limited to, those with a pacemaker, presence of metallic fragments near the eyes or spinal cord, or cochlear implant, any other implanted MRI non-compatible device of any type (cardiac pacemaker, sacral neuromodulation device, and shunt) Patients who are claustrophobic, cannot sign informed consent, or have a past allergic reaction to either Gadobutrol or Ferumoxytol and any history of allergic reaction to any intravenous iron product. Women of child-bearing age who are pregnant or plan to become pregnant (urine pregnancy test will be performed for premenopausal women with no history of prior hysterectomy) Patients who cannot safely refrain from taking any analgesics or steroidal/non-steroidal anti-inflammatory or immunosuppressive drugs for one week preceding the MRI to avoid any confounding effect of anti-inflammatory drugs on bladder permeability. Any patient with a history of allergic reaction to any intravenous iron product.