APP and Alzheimer disease: We also showed that Gd-stained MRI can be used to detect amyloid lesions in models with large compact amyloid plaques such as APPSL/PS1M146L, APP/PS1dE9 or APP23 mice independently of their iron load, and suggest that detection of amyloid plaques by Gd-stained MRI in APPSL/PS1M146L and APP/PS1dE9 is the most similar to that in human-AD brains.