School ager with right flank pain and hematuria after falling off a table

CT of hemorrhage into ureteropelvic junction obstruction after trauma
Coronal (above left) and sagittal (above right) CT with contrast of the abdomen show an extremely dilated right renal collecting system surrounded by an extremely thin rim of renal cortex. The axial image (below) shows high density material within the medial aspect of the renal collecting system.

The diagnosis was hemorrhage into a severe right ureteropelvic junction obstruction in a patient with renal trauma.