Imaging renal mitochondrial dysfunction in chronic kidney disease: a repurposed role for [^99mTc]Tc-MIBI SPECT/CT

[^99mTc]Tc-MIBI is a conventional myocardial perfusion radiotracer, and is predominantly taken up by mitochondria in a manner dependent on mitochondrial membrane potential. This study aimed to repurpose [^99mTc]Tc-MIBI for functional renal imaging to evaluate mitochondrial dysfunction in chronic kidney disease (CKD).

A total of 11 patients with newly diagnosed CKD and 27 matched healthy volunteers underwent [99mTc]Tc-MIBI dynamic renal scans and SPECT/CT. Quantitative analyses of the left kidneys assessed time-activity curves, percentage of renal uptake, and standardized uptake values (SUV). Renal mitochondrial content in CKD patients was evaluated using immunohistochemistry of kidney biopsy samples. CKD patients had comparable eGFR to healthy volunteers but exhibited significantly lower renal [^99mTc]Tc-MIBI uptake percentage on dynamic scan and decreased SUV on SPECT/CT. A positive correlation was observed between mean SUV and renal mitochondrial content in CKD patients. Mean SUV was identified as an independent predictor of CKD (odds ratio 0.2, P = 0.037), demonstrating high diagnostic accuracy (AUC = 0.886), whereas conventional biomarkers had limited predictive value.

[^99mTc]Tc-MIBI kidney SPECT/CT effectively detected renal mitochondrial dysfunction in patients with CKD, suggests its potential as a noninvasive imaging biomarker. SUV may serve as a quantitative parameter for assessing renal mitochondrial dysfunction.