Presentation
Left loin pain and fever.
Patient Data
The parenchyma of left kidney is thinned with large rounded radiolucencies. It contains a large staghorn calculus. A perinephric abscess extending through the posterior pararenal space invovling the psoas muscle is also noted.
There are multiple small stones in the gallbladder (gallstones).
MRI demonstrates an enlarged left kidney with thinned parenchyma, large cystic components and a staghorn calculus. The perinephric abscess extending through the posterior pararenal space involving psoas muscle is better showed.
Gallstones are also noted.
Case Discussion
This case demonstrates imaging findings of xanthogranulomatous pyelonephritis complicated by perinephric abscess involving psoas muscle.