title: Measurement of kidney perfusion by magnetic resonance imaging: comparison of MRI with arterial spin labeling to para-aminohippuric acid plasma clearance in male subjects with metabolic syndrome.
abstract: BACKGROUND
  Magnetic resonance imaging with arterial spin labeling (MRI-ASL) is a non-invasive approach to measure organ perfusion. We aimed to examine whether MRI-ASL kidney perfusion measurements are related to measurements of renal plasma flow (RPF) by para-aminohippuric acid (PAH) plasma clearance and whether changes of kidney perfusion in response to treatment with telmisartan can be detected by MRI-ASL.
  
  
  METHODS
  Twenty-four patients with metabolic syndrome and an estimated creatinine clearance according to Cockroft and Gault of > or =60 ml/min were included in the study. Kidney perfusion was assessed by MRI-ASL measurements of a single coronal kidney slice (with flow-sensitive alternating inversion recovery and true fast imaging with steady-state processing sequence) and by measurements of RPF using PAH plasma clearance before and after 2 weeks of treatment with the angiotensin receptor blocker telmisartan. All MRI-ASL examinations were performed on a 1.5 T scanner.
  
  
  RESULTS
  Two weeks of therapy with telmisartan led to a significant increase of RPF (from 313 +/- 47 to 348 +/- 69 ml/min/m, P = 0.007) and MRI-ASL kidney perfusion measurements (from 253 +/- 20 to 268 +/- 25 ml/min/100 g, P = 0.020). RPF measurements were related with MRI-ASL kidney perfusion measurements (r = 0.575, P < 0.001). Changes of RPF measurements and changes of MRI-ASL kidney perfusion measurements in response to treatment with telmisartan revealed a close relationship when expressed in absolute terms (r = 0.548, P = 0.015) and in percentage changes (r = 0.514, P = 0.025).
  
  
  CONCLUSIONS
  Perfusion measurement of a single coronal kidney slice by MRI-ASL is able to approximate kidney perfusion and to approximate changes in kidney perfusion due to pharmacological intervention.
authors.affiliation: Department of Nephrology and Hypertension, University of Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Ritt
authors.forename: Rolf
authors.initials: R
authors.lastname: Janka
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schneider
authors.forename: Petros
authors.initials: P
authors.lastname: Martirosian
authors.forename: Joachim
authors.initials: J
authors.lastname: Hornegger
authors.forename: Werner
authors.initials: W
authors.lastname: Bautz
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
authors.forename: Roland E
authors.initials: RE
authors.lastname: Schmieder
mesh_terms: D000328:Adult; D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D001158:Arteries / Q000187:drug effects; D001562:Benzimidazoles / Q000627:therapeutic use; D001565:Benzoates / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D003404:Creatinine / Q000378:metabolism; D006439:Hemodynamics; D006801:Humans; D007668:Kidney / Q000098:blood supply*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D008875:Middle Aged; D012079:Renal Circulation; D017595:Renal Plasma Flow / Q000187:drug effects; D013113:Spin Labels; D000077333:Telmisartan; D055815:Young Adult; D010130:p-Aminohippuric Acid / Q000097:blood*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001562:Benzimidazoles; D001565:Benzoates; D013113:Spin Labels; D003404:Creatinine; D000077333:Telmisartan; D010130:p-Aminohippuric Acid