Accuracy of colour duplex sonography for the diagnosis of renal artery stenosis.
OBJECTIVE
To examine the diagnostic value of novel velocimetric colour duplex sonography indices in the screening of renal artery stenosis (RAS).


METHODS
We performed a retrospective analysis of all consecutively studied patients at our centre with suspected RAS, and a colour duplex sonography carried out at less than 4 months (mean 34 days) before renal angiography during a 6-year period (2002-2007). A significant RAS was defined as an at least 60% stenosis on angiography or a transstenotic mean arterial pressure gradient of at least 10 mmHg or both.


RESULTS
In a total of 169 patients, 111 stenotic and 206 nonstenotic kidneys were examined. The sensitivity and specificity for acceleration of blood flow in early systole (ACCmax) were 85 and 75%, respectively, and for the acceleration index (ACCmax/peak systolic velocity, AImax) 83 and 79%, respectively. Corresponding values in patients with estimated glomerular filtration rate of less than 30 ml/min/1.73 m2 were 90 and 73% (for ACCmax) and 74 and 88% (for AImax). In addition, the transstenotic mean arterial pressure gradient showed a significant, though weak, negative correlation to ACCmax (r = -0.26, P = 0.02) and AImax (r = -0.29, P = 0.01) in stenotic kidneys.


CONCLUSIONS
ACCmax and AImax provide similar, good diagnostic accuracy in the detection of a haemodynamically significant RAS, even in patients with markedly reduced glomerular filtration rate. Presumably, the lack of superiority of the novel index AImax could be explained by a highly homogenous methodological approach in the present single-centre study.
Saeed
Aso
A
Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Vita Stråket 12, Sahlgrenska University Hospital, Göteborg S-413 45, Sweden. aso.saeed@vgregion.se
Bergström
Göran
G
Zachrisson
Karin
K
Guron
Gregor
G
Nowakowska-Fortuna
Elzbieta
E
Fredriksen
Ellen
E
Lönn
Lars
L
Jensen
Gert
G
Herlitz
Hans
H
D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies; D013599:Systole; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*