Radiological changes of renal papillary necrosis.

The radiological changes of renal papillary necrosis are independent of its etiology. If total papillary necrosis (TPN) or partial papillary necrosis (PPN) is present, radiological findings are diagnostic. Whereas, if the necrotic papillae remain in situ (NIS) none of the typical radiologic features of papillary necrosis are seen. Serial radiologic studies are useful in renal papillary necrosis. Extension of papillary or medullary cavities, shrinkage of the kidney, and calcification thereby may be noted. Radiologic changes involving the ureter and bladder are those of complications such as ureteritis or development of a transitional cell carcinoma. The latter most often appears in the renal pelvis.