Chronic pyelonephritis is best characterized by which imaging finding?

Chronic pyelonephritis is best characterized by which imaging finding?

• A. Hydronephrosis
• B. Renal stones
• C. Blunted calyces with scarring
• D. Renal abscess

Answer: (C)

Chronic pyelonephritis is driven by long-standing infection that causes tubulointerstitial inflammation and scarring of the renal papillae and calyces. Over time this scarring distorts the collecting system, leading to blunted, irregular calyces and cortical scarring on imaging. This calyceal distortion is the classic, lasting change you’d expect to see, often with asymmetric kidney involvement. Other findings like hydronephrosis reflect dilatation from obstruction rather than the chronic scarring process, renal stones aren’t specific to chronic infection, and a renal abscess represents an acute focal complication rather than the chronic changes described here.

Chronic pyelonephritis is driven by long-standing infection that causes tubulointerstitial inflammation and scarring of the renal papillae and calyces. Over time this scarring distorts the collecting system, leading to blunted, irregular calyces and cortical scarring on imaging. This calyceal distortion is the classic, lasting change you’d expect to see, often with asymmetric kidney involvement. Other findings like hydronephrosis reflect dilatation from obstruction rather than the chronic scarring process, renal stones aren’t specific to chronic infection, and a renal abscess represents an acute focal complication rather than the chronic changes described here.