  Early detection is crucial to prevent the progression of Alzheimer's disease
(AD). Thus, specialists can begin preventive treatment as soon as possible.
They demand fast and precise assessment in the diagnosis of AD in the earliest
and hardest to detect stages. The main objective of this work is to develop a
system that automatically detects the presence of the disease in sagittal
magnetic resonance images (MRI), which are not generally used. Sagittal MRIs
from ADNI and OASIS data sets were employed. Experiments were conducted using
Transfer Learning (TL) techniques in order to achieve more accurate results.
There are two main conclusions to be drawn from this work: first, the damages
related to AD and its stages can be distinguished in sagittal MRI and, second,
the results obtained using DL models with sagittal MRIs are similar to the
state-of-the-art, which uses the horizontal-plane MRI. Although sagittal-plane
MRIs are not commonly used, this work proved that they were, at least, as
effective as MRI from other planes at identifying AD in early stages. This
could pave the way for further research. Finally, one should bear in mind that
in certain fields, obtaining the examples for a data set can be very expensive.
This study proved that DL models could be built in these fields, whereas TL is
an essential tool for completing the task with fewer examples.
