Fig. 2.

MRI findings of the pyelocutaneous fistula after percutaneous nephrostomy (PCN) placement. (A) Coronal MRI demonstrates fluid signal extending from the right renal collecting system toward the posterolateral pararenal region (arrows). (B) Coronal MRI further delineates the fistulous extension along the pararenal space, with the PCN catheter in situ. (C) Axial MRI shows a tract-like extension toward the right lumbar soft tissues adjacent to the nephrostomy tract (arrows). (D) Axial MRI demonstrates inflammatory changes around the right psoas major region and adjacent tissues (arrows), consistent with a complicated fistulous process.