The ARK (also spelled Ark) is a barrel attachment found in the Extinction maps Awakening and Exodus. It allows weapons to turn into a laser weapon, though it still uses conventional ammunition and also has the additional effect of causing extra damage to cryptids, which further makes any that are killed with the weapon it's attached to explode in a similar fashion as to the Pipe Bombs.
A kidney, ureter, and bladder (KUB) study is an X-ray study that allows your doctor to assess the organs of your urinary and gastrointestinal systems. Doctors can use it to help them diagnose urinary disorders and causes of abdominal pain.
CAKUT (Congenital Anomalies of the Kidney and Urinary Tract) Clinic. CAKUT is considered a major cause of renal failure accounting for approximately 40% of cases with end stage kidney disease in children. CAKUT include renal dysplasia, renal hypoplasia, urinary tract obstruction and vesicouretral reflux.