CT Abdomen CT of the abdomen with IV contrast has high accuracy for the diagnosis of APN in a complicated patient but does not allow for a comprehensive assessment of the entire genitourinary tract [1,8,14-21]. CT imaging should include the pelvis to detect potential pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. CTU CTU There is insufficient evidence to support the use of CTU for detection of suspected APN in the complicated patient. There is variability in CTU imaging technique. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to detection and characterization of APN in a complicated patient. DMSA Renal Scan According to the literature, renal scintigraphy, specifically Tc-99m DMSA scan, is not beneficial for the diagnosis of APN in adults. In contrast, renal scintigraphy is useful in the pediatric population where there is difficulty in differentiating lower UTI from APN [23]. However, differentiation of lower UTI from APN is less problematic in adults, and pediatric vesicoureteral reflux often resolves in adulthood. Furthermore, in a small prospective study of adult patients with UTIs who underwent both contrast-enhanced CT and DMSA (n = 36), CT had higher accuracy in diagnosis of APN [24]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Fluoroscopy Voiding Cystourethrography VCUG is commonly used to identify vesicoureteral reflux but is not beneficial in the acute setting. VCUG is usually performed after resolution of acute symptoms to assess for an underlying anatomic or congenital cause, particularly in children with recurrent febrile UTIs [25].
Acute Pyelonephritis. CT Abdomen CT of the abdomen with IV contrast has high accuracy for the diagnosis of APN in a complicated patient but does not allow for a comprehensive assessment of the entire genitourinary tract [1,8,14-21]. CT imaging should include the pelvis to detect potential pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. CTU CTU There is insufficient evidence to support the use of CTU for detection of suspected APN in the complicated patient. There is variability in CTU imaging technique. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to detection and characterization of APN in a complicated patient. DMSA Renal Scan According to the literature, renal scintigraphy, specifically Tc-99m DMSA scan, is not beneficial for the diagnosis of APN in adults. In contrast, renal scintigraphy is useful in the pediatric population where there is difficulty in differentiating lower UTI from APN [23]. However, differentiation of lower UTI from APN is less problematic in adults, and pediatric vesicoureteral reflux often resolves in adulthood. Furthermore, in a small prospective study of adult patients with UTIs who underwent both contrast-enhanced CT and DMSA (n = 36), CT had higher accuracy in diagnosis of APN [24]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Fluoroscopy Voiding Cystourethrography VCUG is commonly used to identify vesicoureteral reflux but is not beneficial in the acute setting. VCUG is usually performed after resolution of acute symptoms to assess for an underlying anatomic or congenital cause, particularly in children with recurrent febrile UTIs [25].