Ultrasound is the imaging study of choice for the initial diagnosis of autosomal dominant polycystic kidney disease (ADPKD) due to its high diagnostic accuracy and ability to detect kidney cysts as small as 2 to 3 mm. MRI of the kidneys is also highly sensitive at detecting small cysts and is an alternative to US. MRI is the preferred modality for determining total kidney volume (TKV). TKV can be used as an imaging biomarker to predict kidney function decline, track disease progression, and eval…