Huang Q, et al. - This study entailed comparison between the performance of technetium-99m-diethylenetriaminepentaacetic acid (^99mTc-DTPA) renal dynamic imaging (RDI), the Modification of Diet in Renal Disease (MDRD) equation, and the Chronic Kidney Disease Epidemiology Collaboration (CKD EPI) equation to estimate glomerular filtration rate (GFR). RDI showed performance no better than MDRD and CKD EPI equations and significantly underestimated GFR. Therefore, it should not be recommended as a reference standard against which other GFR measurement methods are assessed. However, compared with either equation, RDI better estimated GFR for individuals in the true value for GFR (tGFR)30-59 ml/min/1.73 m² group and thus may be helpful to distinguish stage 3a and 3b CKD.