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This Article Full Text Full Text (PDF) All Versions of this Article: 297/4/F1129    most recent 00172.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Kalantarinia, K. Articles by Wei, K. PubMed PubMed Citation Articles by Kalantarinia, K. Articles by Wei, K.

Real-time measurement of renal blood flow in healthy subjects using contrast-enhanced ultrasound

¹Department of Medicine, Division of Nephrology, University of Virginia Health System, Charlottesville; ; ²Cardiovascular Division, Oregon Health and Science University, Portland, Oregon; and ; ³Department of Public Health Sciences, University of Virginia Health System, Charlottesville, Virginia

Submitted March 26, 2009 ; accepted in final form July 15, 2009

Current methods for measuring renal blood flow (RBF) are time consuming and not widely available. Contrast-enhanced ultrasound (CEU) is a safe and noninvasive imaging technique suitable for assessment of tissue blood flow, which has been used clinically to assess myocardial blood flow. We tested the utility of CEU in monitoring changes in RBF in healthy volunteers. We utilized CEU to monitor the expected increase in RBF following a high protein meal in healthy adults. Renal cortical perfusion was assessed by CEU using low mechanical index (MI) power modulation Angio during continuous infusions of Definity. Following destruction of tissue microbubbles using ultrasound at a MI of 1.0, the rate of tissue replenishment with microbubbles and the plateau acoustic intensity (AI) were used to estimate the RBF velocity and cortical blood volume, respectively. Healthy adults (n = 19, mean age 26.6 yr) were enrolled. The A.β parameter of CEU, representing mean RBF increased by 42.8%from a baseline of 17.05 ± 6.23 to 23.60 ± 6.76 dB/s 2 h after the ingestion of the high-protein meal (P = 0.002). Similarly, there was a 37.3%increase in the β parameter, representing the geometric mean of blood velocity after the high protein meal (P < 0.001). The change in cortical blood volume was not significant (P = 0.89). Infusion time of Definity was 6.3 ± 2.0 min. The ultrasound contrast agent was tolerated well with no serious adverse events. CEU is a fast, noninvasive, and practical imaging technique that may be useful for monitoring renal blood velocity, volume, and flow.

renal hemodynamics; renal cortical blood flow; high-protein diet; Definity