MRI and CT features in two unusual cases of xanthogranulomatous pyelonephritis.

Two unusual cases of xanthogranulomatous pyelonephritis studied by both magnetic resonance imaging and computed tomography, are presented. Extension of the disease depicted by both computed tomography and magnetic resonance imaging was compatible with the findings at surgery. Computed tomography seems to be sufficient for xanthogranulomatous pyelonephritis imaging evaluation, while magnetic resonance imaging is not recommended on a routine basis, since no additional valuable information is yielded.