[Abdominal Doppler ultrasonography in the diagnosis of renovascular diseases. Double-blind prospective study].
Our work was aimed at evaluating the sensitivity and specificity and the positive and negative predictive values of abdominal Doppler US in the diagnosis of renovascular disease. Fifty hypertensive patients (23 men and 27 women) with 100 bilaterally single renal arteries (66 of them normal and 34 stenosed) were studied by means of color (26 cases) and duplex (24 cases) Doppler US. The following US variables were considered in the diagnosis of renal artery stenosis: increased peak systolic velocity in the renal artery, increased ratio between peak systolic velocity in the renal artery and in the aorta, increased parenchymal acceleration time and increased resistive index. Feasibility was 100% for all variables. The general multivariate statistic model of discriminate analysis was used to define three calculation levels, according to: a) duplex vs. color Doppler equipment, b) hemodynamic variables and c) optimal cutoff values. US examinations were performed by a single observer in a double-blind study, before angiography, so as to eliminate interobserver variability. On the whole abdominal Doppler US exhibited optimal specificity and fairly good sensitivity. Specificity increased (94% to 97%) with the use of color Doppler according to the different combinations of variables, but sensitivity remained the same. The calculation including all the Doppler variables increased sensitivity from 73% (with true values) to 93% (with threshold values). The positive predictive value demonstrated that 90% of the renal arteries with increased peak systolic velocity and 100% of those with increased parenchymal acceleration time were stenosed. However, the negative predictive value demonstrated that 15% of the renal arteries with no increase in peak systolic velocity is misdiagnosed as normal. In conclusion, abdominal Doppler US can be used to study renovascular disease patients, but the examination must always be based on different hemodynamic variables and true values.
Napoli
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Istituto di Radiologia, Università di Pisa.
Palla
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Pinto
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Pavlica
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Barozzi
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Vignali
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Salvetti
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Bartolozzi
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C
D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014463:Ultrasonography
L'eco-Doppler addominale nella diagnosi della malattia reno-vascolare. Studio prospettico in doppio cieco.