This article shows that measurement of the renal cortical thickness by ultrasonography correlates with the estimated glomerular filtration rate (GFR). This is important because it helps understand that the renal cortical thickness of the left kidney can be used as a way of indirectly estimate the GFR. It also shows that this method is better that the bipolar length of the left kidney. A similar study with a greater sample size than this one (25) would be desirable.
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