Cortical, medullary, and pelvocaliceal MR renography with and without diuretic modification.
OBJECTIVE
This study was conducted to define and characterize magnetic resonance (MR) contrast medium enhancement of the renal cortex, medulla, and pelvocaliceal system in normal and hydronephrotic kidneys with and without furosemide administration.


METHODS
In 30 subjects known or suspected to have unilateral hydronephrosis and normal serum creatinine levels, multiple timed sets of coronal fast spoiled gradient-echo images were acquired before and after contrast medium administration. MR renograms were derived from changes in the signal intensity (SI) of the cortex, medulla, and pelvocaliceal system. Ten subjects received 40 mg of intravenous furosemide approximately 10 minutes before contrast medium administration.


RESULTS
The following values were significantly different between subjects who were given furosemide and those who were not: the peak cortical, medullary, and pelvocaliceal system SIs measured in the normal kidneys during the 4 1/2 minutes following contrast medium administration (163.2 +/- 17.7 [mean arbitrary units plus or minus standard error] vs 120.5 +/- 10.2 [P = .033], 155.5 +/- 18.8 vs 111.5 +/- 9.4 [P = .025], and 332.5 +/- 27.2 vs 229.3 +/- 31.9 [P = .026], respectively); the crossover time between the SI curves of the pelvocaliceal system and the medulla in the normal kidney (2.45 minutes +/- 0.2 vs 3.27 minutes +/- 0.25 [P = .02]); and the peak SIs of the cortex, medulla, and pelvocaliceal system in the unilateral obstructive hydronephrotic kidneys throughout the first 4 1/2 minutes after contrast medium administration (174.6 +/- 16.4 vs 90.6 +/- 13.7 [P = .003], 117.6 +/- 14.1 vs 86.7 +/- 11.8 [P = .015], and 337.2 +/- 41.4 vs 143.1 +/- 74.4 [P = .034], respectively).


CONCLUSIONS
MR renography can be used to depict three separate components of renal enhancement: cortical, medullary, and pelvocaliceal. Furosemide-induced diuresis increases renal parenchymal and pelvocaliceal SI and urinary flow rates.
Katzberg
Richard W
RW
Department of Radiology, University of California, Davis Medical Center, Research Imaging Center, 4701 X St, Sacramento, CA 95817, USA.
Ivanovic
Marija
M
Buonocore
Michael H
MH
Brock
John M
JM
Ryan
John M
JM
D000328:Adult; D016022:Case-Control Studies; D003287:Contrast Media; D004232:Diuretics; D005240:Feasibility Studies; D005260:Female; D005665:Furosemide; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D006869:Hydronephrosis / Q000473:pathology*; D007275:Injections, Intravenous; D007668:Kidney / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009942:Organometallic Compounds
D003287:Contrast Media; D004232:Diuretics; D009942:Organometallic Compounds; D005665:Furosemide; C064925:gadodiamide; D005682:Gadolinium; D019786:Gadolinium DTPA; C112666:gadoversetamide