Measuring glomerular blood transfer rate in kidney using diffusion-weighted arterial spin labeling.

We showed that the perfusion signal consists of two compartments of preglomerular flow and postglomerular flow. The proposed diffusion-weighted arterial spin labeling could measure the glomerular blood transfer rate ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow> <mml:msub><mml:mrow><mml:mi>k</mml:mi></mml:mrow> <mml:mrow><mml:mi>G</mml:mi></mml:mrow> </mml:msub> </mml:mrow> <mml:annotation>$$ {k}_G $$</mml:annotation></mml:semantics> </mml:math> ), which was sensitive enough to noninvasively monitor the caffeine-induced vasodilation of afferent arterioles.