Opacification of the genitourinary collecting system during MDCT urography with enhanced CT digital radiography: nonsaline versus saline bolus.
OBJECTIVE
The purpose of this study was to determine whether a saline bolus during CT urography improves urinary collecting system opacification and whether the addition of enhanced CT digital radiography (CTDR) improves urinary collecting system visualization with or without a saline bolus.


METHODS
One hundred eight CT urography and enhanced CTDR examinations were reviewed. Fifty-four patients were given a saline bolus during CT urography, and 54 patients underwent CT urography without a saline bolus. Urinary collecting system opacification was evaluated by group (saline vs nonsaline), imaging technique (CT urography alone vs CT urography plus enhanced CTDR), number of enhanced CTDR images, and site of nonopacified urinary segments. Using a multivariate logistic regression model, we determined significance of variables and odds of complete opacification.


RESULTS
In the saline group, 248 nonopacified sites were identified on CT urography alone and 95 sites with CT urography plus enhanced CTDR. In the nonsaline group, 185 nonopacified sites were identified on CT urography alone and 59 sites with CT urography plus enhanced CTDR. Combining both groups, 433 nonopacified sites were identified with CT urography alone and 154 sites with CT urography plus enhanced CTDR. Multivariate logistic regression showed significance for group (p = 0.010), imaging method (p < 0.0001), number of enhanced CTDR images (p = 0.048), and site of segment opacification (p < 0.0001). The renal pelvis shows the greatest odds and the distal ureter the lowest odds for complete opacification by group or imaging method.


CONCLUSIONS
The addition of a saline bolus offers no improvement, whereas the addition of enhanced CTDR offers significant improvement in collecting system opacification during CT urography.
Sudakoff
Gary S
GS
Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, 9200 W. Wisconsin Avenue, Milwaukee, WI 53226, USA. gsudakof@mcw.edu
Dunn
Dell P
DP
Hellman
Robert S
RS
Laguna
Mario A
MA
Wilson
Charles R
CR
Prost
Robert W
RW
Eastwood
Daniel C
DC
Lim
Hyun J
HJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006417:Hematuria / Q000000981:diagnostic imaging; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012965:Sodium Chloride; D014057:Tomography, X-Ray Computed; D014567:Urography / Q000379:methods*; D014570:Urologic Diseases / Q000000981:diagnostic imaging*
D012965:Sodium Chloride