Pigmented "muddy brown" granular cast is characteristic of
Prerenal ARF
Ischemic or nephrotoxic ATN
Postrenal ARF
Chronic renal failure
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
Kidney