Clinical Presentation

A teenager with high fever and flank pain.

(A,B) Axial computed tomography images at the level of the kidneys and urinary bladder after oral and intravenous contrast demonstrate a swollen right kidney with wedge-shaped areas of parenchymal hypoattenuation (“striated nephrogram,” arrow) and hydronephrosis. In addition, a several-millimeter calcific density is seen at the right ureterovesical junction (UVJ, arrow).

Differential Diagnosis

• Obstructive uropathy: