Studies comparing MRU with DMSA renal scintigraphy for the detection of pyelonephritis and renal scaring have shown that MRU without and with IV contrast is at least equivalent or superior to DMSA for this specific purpose [33-35]. No studies of MRU without IV contrast were identified in the literature. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. US Abdomen Although US of the abdomen has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess, but it can be performed portably and without IV contrast [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonephritis and for detection of a renal abscess is higher with contrast-enhanced US relative to unenhanced US [37,38]. In one small retrospective study of adults with APN (n = 100), the accuracy of contrast-enhanced US for detection of APN approached that of contrast-enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US including color Doppler has been shown to increase sensitivity for detection of APN beyond grayscale US [40]. US with power Doppler has been shown to have sensitivities and specificities that approach 90% in children with APN [41,42] and may have similar results in adults. Although US has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonep hritis and for detection of a renal abscess is higher with contrast- enhanced US relative to unenhanced US [37,38]. Variant 3: Suspected acute pyelonephritis.
Acute Pyelonephritis. Studies comparing MRU with DMSA renal scintigraphy for the detection of pyelonephritis and renal scaring have shown that MRU without and with IV contrast is at least equivalent or superior to DMSA for this specific purpose [33-35]. No studies of MRU without IV contrast were identified in the literature. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. US Abdomen Although US of the abdomen has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess, but it can be performed portably and without IV contrast [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonephritis and for detection of a renal abscess is higher with contrast-enhanced US relative to unenhanced US [37,38]. In one small retrospective study of adults with APN (n = 100), the accuracy of contrast-enhanced US for detection of APN approached that of contrast-enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US including color Doppler has been shown to increase sensitivity for detection of APN beyond grayscale US [40]. US with power Doppler has been shown to have sensitivities and specificities that approach 90% in children with APN [41,42] and may have similar results in adults. Although US has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonep hritis and for detection of a renal abscess is higher with contrast- enhanced US relative to unenhanced US [37,38]. Variant 3: Suspected acute pyelonephritis.