TSPO and mitochondrial disease: However, if much larger, multicenter studies employing TSPO PET imaging are conducted in the future on patients with mitochondrial disease, the cost, access to tracers or equipment, and reproducibility of imaging in different settings all will have to be taken into account, and the increased sensitivity offered by more accessible and cost-effective second-generation TSPO PET tracers labeled with fluorine-18 may be considered.