Inclusion Criteria:  Male and Female subjects, 18-40 years of age, inclusive Previous diagnosis of ADPKD (Based on Ravine et al. criteria) Class 1 according to imaging classification Estimated GFR>70 mL/min/1.73m^2(CKD-EPI) Ability to provide written, informed consent.  Exclusion Criteria:  Class 2 according to imaging classification A concomitant systemic disease affecting the kidney Diabetes mellitus Predicted urine protein excretion in urinalysis >1 g/24 hrs Subjects having contraindications to or interference with MRI assessments Patients that are part of an interventional study or taking tolvaptan Female subjects that are pregnant