Radiopharmaceuticals in Renal Imaging: A Comprehensive Review of Current Applications and Future Prospects

The kidneys play a vital role in filtration, excretion, and metabolic regulation, making accurate functional assessment essential for diagnosis, monitoring, and management of renal diseases. While conventional imaging modalities such as ultrasonography, computed tomography (CT), and multiparametric magnetic resonance imaging (MRI) provide structural and functional information, nuclear medicine techniques enable more detailed evaluation of renal physiology at the molecular level. This review provides a comprehensive overview of functional renal imaging using both conventional renal scintigraphy and emerging positron emission tomography (PET) radiopharmaceuticals. Established renal scintigraphy radiopharmaceuticals, including ^99mTc-DTPA, ^99mTc-DMSA, ^99mTc-MAG3, and ^99mTc-EC, have long been applied to assess glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). PET radiopharmaceuticals, offering higher sensitivity, superior quantification, and molecular insight, are increasingly investigated for similar purposes, with ⁶⁸Ga-EDTA, ⁶⁸Ga-DTPA, ⁶⁸Ga-NOTA, ⁶⁸Ga-DOTA, and ¹⁸F-FDS for GFR assessment and ¹¹C-PABA, ¹⁸F-PFH, Re-(CO)₃(¹⁸F-FEDA), and Al-¹⁸F-NODA-butyric acid for ERPF evaluation. Additional PET tracers, including ⁶⁸Ga-IRDye800-tilmanocept, ¹⁸F-FDG, and ⁶⁸Ga-PSMA-11, have been explored for glomerular mesangial function, renal tumors, and split renal function, respectively. By systematically summarizing both renal scintigraphy and PET approaches, this review highlights current and emerging PET radiopharmaceuticals for renal functional imaging and discusses their potential clinical applications and future perspectives in precision nephrology.