title: Renal perfusion evaluation with contrast-enhanced ultrasonography.
abstract: BACKGROUND
  Contrast-enhanced ultrasonography (CEUS) is a novel imaging technique that is safe and applicable on the bedside. Recent developments seem to enable CEUS to quantify organ perfusion. We performed an exploratory study to determine the ability of CEUS to detect changes in renal perfusion and to correlate them with effective renal plasma flow.
  
  
  METHODS
  CEUS with destruction-refilling sequences was studied in 10 healthy subjects, at baseline and during infusion of angiotensin II (AngII) at low (1 ng/kg/min) and high dose (3 ng/kg/min) and 1 h after oral captopril (50 mg). Perfusion index (PI) was obtained and compared with the effective renal plasma flow (ERPF) obtained by parallel para-aminohippurate (PAH) clearance.
  
  
  RESULTS
  Median PI decreased from 188.6 (baseline) to 100.4 with low-dose AngII (-47%; P < 0.02) and to 66.1 with high-dose AngII (-65%; P < 0.01) but increased to 254.7 with captopril (+35%; P > 0.2). These changes parallelled those observed with ERPF, which changed from a median of 672.1 mL/min (baseline) to 572.3 (low-dose AngII, -15%, P < 0.05) and to 427.2 (high-dose AngII, -36%, P < 0.001) and finally 697.1 (captopril, +4%, P < 0.02).
  
  
  CONCLUSIONS
  This study demonstrates that CEUS is able to detect changes in human renal cortical microcirculation as induced by AngII infusion and/or captopril administration. The changes in perfusion indices parallel those in ERPF as obtained by PAH clearance.
authors.affiliation: Department of Internal Medicine, Division of Nephrology and Hypertension, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Antoine G
authors.initials: AG
authors.lastname: Schneider
authors.forename: Lucie
authors.initials: L
authors.lastname: Hofmann
authors.forename: Grégoire
authors.initials: G
authors.lastname: Wuerzner
authors.forename: Nicolas
authors.initials: N
authors.lastname: Glatz
authors.forename: Marc
authors.initials: M
authors.lastname: Maillard
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Meuwly
authors.forename: Philippe
authors.initials: P
authors.lastname: Eggimann
authors.forename: Michel
authors.initials: M
authors.lastname: Burnier
authors.forename: Bruno
authors.initials: B
authors.lastname: Vogt
mesh_terms: D000328:Adult; D000804:Angiotensin II / Q000494:pharmacology*; D002216:Captopril / Q000494:pharmacology*; D015331:Cohort Studies; D003287:Contrast Media; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007672:Kidney Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000187:drug effects; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D015588:Observer Variation; D012016:Reference Values; D012079:Renal Circulation / Q000187:drug effects* / Q000502:physiology; D017596:Renal Plasma Flow, Effective / Q000187:drug effects; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods; D055815:Young Adult
chemical_list: D003287:Contrast Media; D000804:Angiotensin II; D002216:Captopril