during the course of acute rejection , there was a spectrum of sonographic findings including increase in renal volume , decreased amplitude of the renal sinus echoes , enlarged medullary pyramids , indistinct corticomedullary boundary , increased echogenicity of the renal cortex , areas of decreased parenchymal echogenicity , sparse cortical echoes , and perirenal fluid collections as a result of hematoma or crescentic collection of fluid around the kidney .
C0227629
medullary pyramids
C0022646
kidney