title: Comprehensive MR evaluation of renal disease: added clinical value of quantified renal perfusion values over single MR angiography.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of quantified renal perfusion parameters in identifying and differentiating renovascular from renal parenchymal disease.
  
  
  METHODS
  In all, 27 patients underwent renal perfusion measurements on a 3.0 T magnetic resonance imaging (MRI) system. Imaging was performed with a saturation recovery TurboFLASH sequence (TR/TE 177/0.93 msec, flip angle 12 degrees , 5 slices/sec). All patients also underwent high-resolution MR angiography (MRA) (TR/TE 3.1/1.09, flip angle 23 degrees , spatial resolution 0.9 x 0.8 x 0.9 mm(3)). MR perfusion measurements were analyzed with a two-compartment model, quantifying the plasma flow (F(P))-a characteristic renal first-pass perfusion parameter. A receiver-operator characteristic analysis was used to determine the optimal threshold value for distinguishing normal and abnormal plasma flow values. Utilizing this cutoff, sensitivity and specificity of solitary MR perfusion measurements, MRA, and a diagnostic strategy combining the two were evaluated.
  
  
  RESULTS
  Quantified MR perfusion values yielded a sensitivity of 100% and a specificity of 85% utilizing the optimal plasma flow threshold value of 150 mL/100 mL/min, whereas single MRA achieved a sensitivity of 51.9% and a specificity of 90%. Combining both methods enabled improved detection of renovascular and renoparenchymal disease with a sensitivity of 96.3% and specificity of 90%.
  
  
  CONCLUSIONS
  In distinction to MRA, quantified MR perfusion measurements allow for the detection of pure renal parenchymal disorders. The combination of MRA with these perfusion measurements suggests an algorithm by which parenchymal and renovascular diseases may be reliably distinguished and the hemodynamic significance of the latter reliably determined.
authors.affiliation: Department of Clinical Radiology, University Hospitals Munich - Grosshadern, Ludwig-Maximilians-University, Munich, Germany. ulrike.attenberger@medma.uni-heidelberg.de
authors.forename: Ulrike I
authors.initials: UI
authors.lastname: Attenberger
authors.forename: Steven P
authors.initials: SP
authors.lastname: Sourbron
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: John
authors.initials: J
authors.lastname: Morelli
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
authors.forename: Gita M
authors.initials: GM
authors.lastname: Schoeppler
authors.forename: Walter
authors.initials: W
authors.lastname: Samtleben
authors.forename: Krista L
authors.initials: KL
authors.lastname: Birkemeier
authors.forename: Christian
authors.initials: C
authors.lastname: Glaser
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: Michaely
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007674:Kidney Diseases / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity