Simultaneous magnetic resonance imaging of pH, perfusion and renal filtration using hyperpolarized ¹³C-labelled...

pH alterations are a hallmark of many pathologies including cancer and kidney disease. Here, we introduce [1,5-¹³C₂]Z-OMPD as a hyperpolarized extracellular pH and perfusion sensor for MRI which allows to generate a multiparametric fingerprint of renal disease status and to detect local tumor acidification. Exceptional long T₁ of two minutes at 1 T, high pH sensitivity of up to 1.9 ppm per pH unit and suitability of using the C₁-label as internal frequency reference enables pH imaging in vivo of three pH compartments in healthy rat kidneys. Spectrally selective targeting of both ¹³C-resonances enables simultaneous imaging of perfusion and filtration in 3D and pH in 2D within one minute to quantify renal blood flow, glomerular filtration rates and renal pH in healthy and hydronephrotic kidneys with superior sensitivity compared to clinical routine methods. Imaging multiple biomarkers within a single session renders [1,5-¹³C₂]Z-OMPD a promising new hyperpolarized agent for oncology and nephrology.