Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) has limited utility in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. Although radiography of the abdomen and pelvis could detect large calculi, it cannot detect APN. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. US Abdomen US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Some 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 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 o f APN approached that of contrast- enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Use of color Doppler has been shown to increase sensitivity for detection of APN in adults and children [40-42]. Inclusion of the bladder could identify other abnormalities contributing to APN. A disadvantage of US compared with CT is a lower rate of detection of APN and renal abscess [10,36-38]. Variant 4: Suspected acute pyelonephritis. Pregnant patient with no other complications (eg, no history of diabetes, immune compromise, history of stones or renal obstruction, prior renal surgery, vesicoureteral reflux, or lack of response to therapy). Initial imaging.
Acute Pyelonephritis. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) has limited utility in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. Although radiography of the abdomen and pelvis could detect large calculi, it cannot detect APN. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. US Abdomen US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Some 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 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 o f APN approached that of contrast- enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Use of color Doppler has been shown to increase sensitivity for detection of APN in adults and children [40-42]. Inclusion of the bladder could identify other abnormalities contributing to APN. A disadvantage of US compared with CT is a lower rate of detection of APN and renal abscess [10,36-38]. Variant 4: Suspected acute pyelonephritis. Pregnant patient with no other complications (eg, no history of diabetes, immune compromise, history of stones or renal obstruction, prior renal surgery, vesicoureteral reflux, or lack of response to therapy). Initial imaging.