A Study to Evaluate Renal Fibrosis Using MRI Techniques

Inclusion Criteria: * Between ages 40 and 80 years old. * Patients with hypertension (BP\>140/90 mmHg) and/or requirement for two or more antihypertensive medications for more than 4 weeks. * Serum creatinine under 2.2 and 2.0 mg/dL for men and women, respectively (Caucasians). Values for African-American subjects are slightly higher (2.4 mg/dL, males; 2.1 mg/dL females). * No contraindications to angiography: severe contrast allergy. * No contraindications to no-contrast MR evaluations: e.g. pacemaker or magnetically active metal fragments, claustrophobia. * Patients have the ability to comply with protocol * Patients are competent and able to provide written informed consent Exclusion Criteria: * Patient has serum creatinine \>2.2 mg/dL for men and \>2.0 mg/dL for women (Caucasians); \>2.4 mg/dL for men and \>2.1 mg/dL for women (African American). * RVD in a solitary kidney * Patients have clinically significant medical conditions within the prior six months: e.g. myocardial infarction, congestive heart failure, stroke, that would, in the opinion of the investigators, compromise the safety of the patient. * Uncontrolled hypertension (Systolic BP \>180 mmHg despite therapy). * Diabetes requiring insulin or oral hypoglycemic medications. * Evidence of hepatitis B or C, or HIV infection. * Requirement for potentially nephrotoxic drugs; e.g., non-steroidal anti-inflammatory drugs. * Cardiac ejection fraction less than 30%. * History of deep venous thrombosis within 3 months…