title: Cortical, medullary, and pelvocaliceal MR renography with and without diuretic modification.
abstract: 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.
authors.affiliation: Department of Radiology, University of California, Davis Medical Center, Research Imaging Center, 4701 X St, Sacramento, CA 95817, USA.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Katzberg
authors.forename: Marija
authors.initials: M
authors.lastname: Ivanovic
authors.forename: Michael H
authors.initials: MH
authors.lastname: Buonocore
authors.forename: John M
authors.initials: JM
authors.lastname: Brock
authors.forename: John M
authors.initials: JM
authors.lastname: Ryan
mesh_terms: 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
chemical_list: D003287:Contrast Media; D004232:Diuretics; D009942:Organometallic Compounds; D005665:Furosemide; C064925:gadodiamide; D005682:Gadolinium; D019786:Gadolinium DTPA; C112666:gadoversetamide