- 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
- Complications: focus of infection can progress to abscess
- Clinical: when the diagnosis of a “mass” (lobar nephronia) is made get a followup US in 1 month to ensure the “mass” has resolved
Radiology Cases of Acute Pyelonephritis


