title: MR renography using a dynamic gradient-echo sequence and low-dose gadopentetate dimeglumine as an alternative to radionuclide renography.
abstract: OBJECTIVE
  Our aim was to evaluate the feasibility of acquiring an MR signal intensity-time renographic curve and dynamic serial images in a way similar to that of acquiring radionuclide renograms, with a dynamic gradient-echo sequence and a low-dose gadopentetate dimeglumine technique, using a commonly available 1.5-T MR scanner. SUBJECTS AND METHODS. Patients who underwent both radionuclide and MR renographic studies within a 3-month period were included in the analysis. This yielded 21 studies from 19 patients. Nineteen of the 21 studies were available for analysis. Two studies were excluded because of technical errors during MR renographic acquisition. Serial MR renograms were obtained using a dynamic two-dimensional spoiled gradient-echo fast low-angle shot T1-weighted sequence. Low-dose IV furosemide and gadopentetate dimeglumine (0.025 mmol/kg of body weight) were administered. Intensity-time curves were obtained from the manually selected regions of interest over the renal parenchyma and whole kidney for calculation of split renal function and assessment of urinary excretion, respectively. Results were compared with those obtained with radionuclide renography.
  
  
  RESULTS
  Good correlation (Pearson's correlation coefficient, r = 0.97, p < 0.001) was observed when the volume-corrected split renal function acquired with MR renography was compared with that obtained with radionuclide renography. There was also good agreement in the excretory curve patterns (weighted kappa(observer 1) = 0.77 and kappa(observer 2) = 0.81) between the two techniques.
  
  
  CONCLUSIONS
  Dynamic MR gradient-echo imaging with a low-dose gadopentetate dimeglumine technique can produce an intensity-time curve and serial dynamic images of the urinary system, in a way similar to that of radionuclide renography. This technique allows assessment of split renal function and urinary excretory status and is a feasible alternative to radionuclide renography.
authors.affiliation: Department of Radiology, Changi General Hospital, 2, Simei St. 3, S, 529889 Singapore.
authors.forename: Hui Seong
authors.initials: HS
authors.lastname: Teh
authors.forename: Ee Sin
authors.initials: ES
authors.lastname: Ang
authors.forename: Weng Cheong
authors.initials: WC
authors.lastname: Wong
authors.forename: Say Beng
authors.initials: SB
authors.lastname: Tan
authors.forename: Andrew Gee Seng
authors.initials: AG
authors.lastname: Tan
authors.forename: Soke Miang
authors.initials: SM
authors.lastname: Chng
authors.forename: Michael Beng Kiang
authors.initials: MB
authors.lastname: Lin
authors.forename: Jeffery Seow Kuang
authors.initials: JS
authors.lastname: Goh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D004232:Diuretics / Q000008:administration & dosage; D005260:Female; D005665:Furosemide / Q000008:administration & dosage; D019786:Gadolinium DTPA; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011866:Radioisotope Renography; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D014570:Urologic Diseases / Q000175:diagnosis
chemical_list: D003287:Contrast Media; D004232:Diuretics; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D005665:Furosemide; D019786:Gadolinium DTPA