Medullary nephrocalcinosis due to renal tubular acidosis (RTA)

Plain film (A) showing innumerable small calcifications in the region of the renal medulla. Ultrasound of the right (B) and left (C) kidneys shows increased echogenicity of the medulla with diffuse shadowing. Noncontrast CT (D and E) shows numerous calcifications in the renal medulla. This patient has medullary nephrocalcinosis due to renal tubular acidosis.