Glomerular filtration rate calculation based on 68 Ga-EDTA dynamic renal PET.

Positron emission tomography (PET) can accurately locate and quantify radioactivity over traditional single photon emission computed tomography (SPECT), encouraging its application in kidney function evaluation and glomerular filtration rate (GFR) measurement. 68 Ga-ethylenediamine-tetraacetic acid (68 Ga-EDTA) is a novel PET tracer for renal scan but a mature GFR calculation method still pending establishment. Herein, we aim to investigate the imaging performance of 68 Ga-EDTA dynamic PET in healthy C57BL/6 mice, establish quantitative methods to calculate GFR, and evaluate its feasibility in mice with kidney dysfunction. Dynamic PET of 68 Ga-EDTA successfully visualized the whole process of tracer elimination. GFR values were measured by the integral method (253.80±40.11 μL/min) and the Patlak Plot method (22.69±9.75 μL/min), while blood clearance rate of the tracer was found at 787.46±70.86 μL/min. The PET-based GFR values correlate well with the GFRblood (R2 =0.7468, R2 =0.8793). The Integral method provides better accuracy than Patlak Plot method. Further application of GFR measurement in kidney-diseased mice proves better performance of the Integral method for defining split renal function.