International Journal of Nephrology [49] S. E. Haufe, K. Riedmu¨ller, and U. Haberkorn, “Nuclear medicine procedures for the diagnosis of acute and chronic renal failure,” Nephron, vol. 103, no. 2, pp. c77–c84, 2006. [50] S. Swaminathan and S. V. Shah, “New insights into nephro- genic systemic ﬁbrosis,” Journal of the American Society of Nephrology, vol. 18, no. 10, pp. 2636–2643, 2007. [51] M. R. Prince, H. Zhang, M. Morris et al., “Incidence of nephrogenic systemic ﬁbrosis at two large medical centers,” Radiology, vol. 248, no. 3, pp. 807–816, 2008. [52] R. A. O’Rourke, J. R. Lindner, and K. Wei, “Contrast echocardiography,” Current Problems in Cardiology, vol. 27, no. 11, pp. 449–519, 2002. [53] K. Kalantarinia, J. T. Belcik, J. T. Patrie, and K. Wei, “Real- time measurement of renal blood ﬂow in healthy subjects using contrast-enhanced ultrasound,” American Journal of Physiology, vol. 297, no. 4, pp. F1129–F1134, 2009. [54] K. Wei, E. Le, J. P. Bin, M. Coggins, J. Thorpe, and S. Kaul, “Quantiﬁcation of renal blood ﬂow with contrast-enhanced ultrasound,” Journal of the American College of Cardiology, vol. 37, no. 4, pp. 1135–1140, 2001. [55] T. Schlosser, C. Pohl, C. Veltmann et al., “Feasibility of the ﬂash-replenishment concept in renal tissue: which parameters aﬀect the assessment of the contrast replenishment?” Ultra- sound in Medicine and Biology, vol. 27, no. 7, pp. 937–944, 2001. [56] Y. Hosotani, N. Takahashi, H. Kiyomoto et al., “A new method for evaluation of split renal cortical blood ﬂow with contrast echography,” Hypertension Research, vol. 25, no. 1, pp. 77–83, 2002. [57] N. Kishimoto, Y. Mori, T. Nishiue et al., “Ultrasound eval- uation of valsartan therapy for renal cortical perfusion,” Hypertension Research, vol. 27, no. 5, pp. 345–349, 2004. [58] F. Lefe`vre, J. M. Correas, S. Brianc¸on, O. He´le´non, M. Kessler, and M. Claudon, “Contrast-enhanced sonography of the renal transplant using triggered pulse-inversion imaging: preliminary results,” Ultrasound in Medicine and Biology, vol. 28, no. 3, pp. 303–314, 2002. [59] R. Lencioni, S. Pinto, D. Cioni, and C. Bartolozzi, “Contrast- enhanced doppler ultrasound of renal artery stenosis: pro- logue to a promising future,” Echocardiography, vol. 16, no. 7, pp. 767–773, 1999. [60] S. M. Gruenewald, T. Huster, G. Larcos, D. C. Farlow, K. K. L. Choong, and Y. Mudaliar, “Acute renal failure in critically ill patients: evaluation of an ultrasound contrast agent,” Australasian Radiology, vol. 43, no. 2, pp. 180–184, 1999. [61] J. M. Correas, M. Claudon, F. Tranquart, and O. He´le´non, “The kidney: imaging with microbubble contrast agents,” Ultrasound Quarterly, vol. 22, no. 1, pp. 53–66, 2006. 7