Inclusion Criteria:  Patients, male or female and older than 18 years of age. Patients diagnosed with persistent or paroxysmal AF. Patients that are undergoing catheter ablation at Tulane University Medical Center. Patients that had a cardiac MRI prescribed by their physician as part of their standard of care.  Exclusion Criteria:  Patients with coagulation disorders such as, von Willebrand disease, hemophilia, Immune Thrombocytopenic Purpura, etc. Patients who are pregnant or breast-feeding or plan to become pregnant during the study period. Are not surgically sterile. Are of childbearing potential and are unwilling to practice two acceptable methods of birth control. Do not plan to continue practicing two acceptable methods of birth control throughout the trial (highly effective methods of birth control are defined as those, used alone or in combination, that result in a low failure rate i.e. less than 1% per year when used consistently and correctly). Patients with mental and/or physical ailments which may prohibit them from actively participating in the study. Any health-related gadolinium/MRI contraindications (e.g. allergy to gadolinium, pacemakers, Implantable Cardioverter Defibrillators (ICD's), other devices/implants contraindicated for use of MRI, etc.) Patients who have a known terminal illness with a prognosis less than 12 months at the time of the informed consent process. Planned cardiovascular intervention. Patient with diagnosed acute or chronic severe kidney disease or with a low glomerular filtration rate (GFR), <30 mL per minute per 1.73 m2 Patients who cannot read, speak, and/or understand English. Patients with cognitive impairments who are unable to give informed consent.