Complicated Genitourinary Tract Infections and Mimics.

This article provides pictorial review of complicated upper and lower genitourinary infections and their mimics. Imaging features of upper urinary tract infections including uncomplicated acute pyelonephritis, xanthogranulomatous pyelonephritis (XGPN), emphysematous pyelonephritis, perirenal abscess, and pyonephrosis are first reviewed and then followed by pictorial review of their mimics including contrast-associated nephrotoxicity, renal infarcts, malakoplakia, renal cell cancer, leukemia or lymphoma and Castleman's disease. Next, imaging features of lower urinary tract infections including cystitis, emphysematous cystitis, enterovesical, colovesical and vesicovaginal fistulas, Fournier gangrene, prostatitis, epididymitis, and orchitis are reviewed and then followed by pictorial review of their mimics including gas in the bladder and perineum related to instrumentation, radiation cystitis, bladder cancer, testicular torsion, testicular trauma, and testicular cancer and lymphoma. Recognizing imaging characteristics of complicated genitourinary infections and their mimics would allow clinicians to provide appropriate timely management.