CT Abdomen Without and With IV Contrast There is limited evidence to support the use of CT abdomen without and with IV contrast (separate from CTU) for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause. CT Abdomen Without IV Contrast There is limited evidence to support the use of CT abdomen without IV contrast (separate from CTU) for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause. CTU Without and With IV Contrast Although there is limited evidence to support the use of CTU without and with IV contrast for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause, CTU is useful for investigating the etiology of hydronephrosis. CTU provides a near- comprehensive evaluation of the genitourinary tract including both morphological and functional information. DTPA Renal Scan DRG is the de facto standard of care in diagnosis of renal obstruction [10] and can be used to determine whether obstructive uropathy is truly present in cases of incidentally noted hydronephrosis [11]. However, tubular tracers (eg, MAG3 and 123I) are much more efficiently extracted by the kidney than DTPA, and washout is therefore easier to evaluate with tubular tracers. Use of DTPA for diuretic renography may result in an equivocal or false-positive diuretic study compared with MAG3, particularly in patients with reduced function, and is not favored for imaging only studies [11,12]. DRG with DTPA is useful for estimating single-kidney GFR, although it may somewhat overestimate global GFR in the setting of obstructive hydronephrosis [13].
Hydronephrosis on Prior Imaging Unknown Cause. CT Abdomen Without and With IV Contrast There is limited evidence to support the use of CT abdomen without and with IV contrast (separate from CTU) for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause. CT Abdomen Without IV Contrast There is limited evidence to support the use of CT abdomen without IV contrast (separate from CTU) for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause. CTU Without and With IV Contrast Although there is limited evidence to support the use of CTU without and with IV contrast for initial imaging of patients with asymptomatic bilateral hydronephrosis or asymptomatic hydronephrosis in a solitary kidney with unknown cause, CTU is useful for investigating the etiology of hydronephrosis. CTU provides a near- comprehensive evaluation of the genitourinary tract including both morphological and functional information. DTPA Renal Scan DRG is the de facto standard of care in diagnosis of renal obstruction [10] and can be used to determine whether obstructive uropathy is truly present in cases of incidentally noted hydronephrosis [11]. However, tubular tracers (eg, MAG3 and 123I) are much more efficiently extracted by the kidney than DTPA, and washout is therefore easier to evaluate with tubular tracers. Use of DTPA for diuretic renography may result in an equivocal or false-positive diuretic study compared with MAG3, particularly in patients with reduced function, and is not favored for imaging only studies [11,12]. DRG with DTPA is useful for estimating single-kidney GFR, although it may somewhat overestimate global GFR in the setting of obstructive hydronephrosis [13].