Acute Pyelonephritis

  • Etiology: ascending urinary tract infection or hematogenous infection
  • US: focal spherical swelling, hypoechoic, hypoperfused on color / power doppler US
  • CT: low density on contrast enhanced CT, striated nephrogram
  • DDX: renal tumor which will not resolve on antibiotics
  • Clinical: focus of infection can progress to abscess

Cases of Acute Pyelonephritis

CT of acute pyelonephritis
Immediate (above) and delayed (below) axial CT with contrast of the abdomen shows multiple low density wedge-shaped lesions in the left kidney and a striated nephrogram on the delayed images.