This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Oktar, S. O. Articles by Karaosmanoglu, D. Search for Related Content PubMed PubMed Citation Articles by Oktar, S. O. Articles by Karaosmanoglu, D.

Doppler Sonography of Renal Obstruction

Value of Venous Impedance Index Measurements

Department of Radiology, School of Medicine, Gazi University, Ankara, Turkey.

Address correspondence and reprint requests to Suna Özhan Oktar, MD, Gazi Üniversitesi Tip Fakültesi, Radyoloji Anabilim Dali, 06510 Besevler, Ankara, Turkey. E-mail: sunaoktar{at}gazi.edu.tr.

Objective. Arterial resistive index values have poor sensitivity and specificity for alterations in renal perfusion induced by collecting system obstruction. We aimed to determine whether the intrarenal venous impedance index values could be useful in evaluating renal parenchymal compliance in cases of obstruction and in differentiating acute obstruction from chronic cases. Methods. Fifteen patients with acute renal colic having unilateral stone disease and another 15 patients having unilateral chronic obstruction due to various causes were evaluated sonographically. The diagnosis was confirmed either by computed tomography or intravenous urography in all cases. Fifteen subjects with normal kidneys were investigated as a control group. All patients were examined prospectively by conventional and Doppler sonography. The impedance indices and peak flow signals of the interlobar arteries and veins of both kidneys were calculated from spectral Doppler waveforms in all 3 groups. Results. The mean venous impedance index on the acutely obstructed side was lower than the index on the unobstructed side: 0.25 ± 0.07 and 0.53 ± 0.3 (mean ± SD), respectively (P = .005). The mean venous impedance index on the acutely obstructed side was less than the indices both on the chronically obstructed side and in the control subjects (P > .0001). In acute cases, the mean arterial resistive index on the obstructed side was higher than the index on the unobstructed side: 0.62 ± 0.06 and 0.57 ± 0.06, respectively (P = .001). No statistically significant difference was detected between other parameters evaluated for the test and control groups. Conclusions. Renal venous impedance index values may be helpful in evaluating renal hemodynamics in obstruction and in differentiating acute obstruction from chronic cases when used in conjunction with the arterial resistive index.

Key Words: Doppler sonography • renal hemodynamics • urinary tract

Abbreviations: RI, resistive index

This article has been cited by other articles:

				S J Freeman and H Sells Investigation of loin pain Imaging, August 1, 2005; 17(1): 19 - 33. [Abstract] [Full Text] [PDF]

				F. Tranquart and S. O. Oktar Doppler Sonography of Renal Obstruction * Reply J. Ultrasound Med., December 1, 2004; 23(12): 1684 - 1685. [Full Text] [PDF]