Utility of Quantitative Indices Derived From 67Ga-SPECT/CT in Initial Diagnosis and Follow-up of Nephritis

We present a case of nephritis wherein quantitative indices derived from Gallium-67 ( 67 Ga) citrate scintigraphy (Ga-S) were used for the initial diagnosis and longitudinal monitoring of inflammatory activity over 2.5 years. Quantitative indices, including the maximum standardized uptake value (SUV max ), active nephritis volume (ANV), and total nephritis uptake (TNU), were calculated from baseline and follow-up SPECT/CT scans. Laboratory and clinical data were simultaneously assessed. The Baseline SUV max , ANV, and TNU were 13.8, 316, and 2553, respectively. Follow-up imaging demonstrated significant reductions (SUV max =4.5; ANV=147 cm 3 ; TNU=401) without pharmacological intervention, correlating with improvement in creatinine, CRP, and resolution of proteinuria. Quantitative Ga-S indices may serve as objective and reproducible biomarkers for monitoring renal inflammation, particularly in patients who cannot undergo biopsy.