MAPT and Alzheimer disease: However, use of biomarkers remain critical and are required to help better distinguish both process, with the use of the MRI brain showing disproportional hippocampal atrophy as a marker of LATE-NC, as well as the presence or absence of AD biomarkers to classify the underlying pathology better and assess for AD; in case of positive AD biomarkers, additional testing is required using PET scan (tau PET and FDG-PET scan) (Wolk et al., 2025).