Significant differences in DKI parameters for each ROI between the AD and normal cognition groups were as follows (p < 0.05): frontal lobe: MD and MK; parietal lobe: MD, Dr, and FAK; occipital lobe: MD and Dr; temporal lobe: FA, MD, Dr, FAK, MK, and Kr; precuneus: MD, Da, Dr, MK, Ka, and Kr; hippocampus: MD, Da, Dr, FAK, MK, Ka, and Kr; splenium of the corpus callosum: MD and MK; genu of the corpus callosum: MD, Dr, MK, and Kr; the posterior limb of the internal capsule: MD, Da, and MK; lenticular nucleus: Da and Kr; corona radiata: MD and MK; centrum semiovale: FA, MD, Dr, FAK, and MK. The gene discussed is PTK2; the disease is Alzheimer disease.