title: Assessment of renal artery stenosis: side-by-side comparison of angiography and duplex ultrasound with pressure gradient measurements.
abstract: OBJECTIVE
  A ratio of distal renal pressure to aortic pressure (P(d)/P(a)) <0.90 can be considered a threshold for defining a significant renal artery stenosis (RAS). The aim of this study was to compare renal angiography (QRA) and colour duplex ultrasound (CDUS) to pressure measurements in assessing RAS.
  
  
  RESULTS
  In 56 RAS, percent diameter stenosis (DS(angio)), minimal luminal diameter (MLD), Doppler-derived peak systolic velocity (PSV), end-diastolic velocity (EDV), and renal-to-aortic ratio (RAR) were obtained and compared with the P(d)/P(a) measured with a 0.014" pressure wire. P(d)/P(a) correlated with angiography- and CDUS-derived parameters. The best correlation was observed with EDV (R = -0.61). To identify stenosis associated with a P(d)/P(a) < 0.90, the diagnostic accuracy of DS(angio) > 50%, MLD < 2 mm, PSV > 180 cm/s, EDV > 90 cm/s and RAR > 3.5 were, respectively, 60%, 77%, 45%, 77% and 79%, yet, with a high proportion of false positives (38%, 15%, 55%, 11% and 15%, respectively) indicating an overestimation of the severity of the RAS by both QRA and CDUS. New cut-off values for QRA- and CDUS-derived indices were proposed.
  
  
  CONCLUSIONS
  Generally accepted QRA and CDUS-derived indices of RAS severity overestimate the actual severity of RAS. This 'overdiagnosis' is likely the main cause of the disappointing results of renal angioplasty for renovascular hypertension.
authors.affiliation: Cardiovascular Center, OLV Clinic, Moorselbaan 164, 9300 Aalst, Belgium.
authors.forename: Benny
authors.initials: B
authors.lastname: Drieghe
authors.forename: Juraj
authors.initials: J
authors.lastname: Madaric
authors.forename: Giovanna
authors.initials: G
authors.lastname: Sarno
authors.forename: Ganesh
authors.initials: G
authors.lastname: Manoharan
authors.forename: Jozef
authors.initials: J
authors.lastname: Bartunek
authors.forename: Guy R
authors.initials: GR
authors.lastname: Heyndrickx
authors.forename: Nico H J
authors.initials: NH
authors.lastname: Pijls
authors.forename: Bernard
authors.initials: B
authors.lastname: De Bruyne
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D004812:Epidemiologic Methods; D006801:Humans; D006978:Hypertension, Renovascular / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D012078:Renal Artery Obstruction / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*