<prompt> Pigmented muddy brown granular cast is characteristic ofPrerenal ARFIschemic or nephrotoxic ATNPostrenal ARFChronic renal failure  <response>: AKI from ATN due to ischemic injury, sepsis, or ceain nephrotoxins has characteristic urine sediment findings: pigmented muddy brown granular casts and tubular epithelial cell casts. These findings may be absent in more than 20 of cases Ref: Harrison 19e pg: 1805 