Synopsis

In this presentation we will give an overview of MRI in Brazil, and we will present a challenge that is potentially of interest to other South American countries. The challenge proposed is to merge clinical data with MRI brain scans of people with not known neurological problem, in order to establish which is the age/gender specific treshold at which MRI lesions compatible with vascular dementia start to occur. The goal would be then to identify who are the patients at risk of vascular dementia in order to make an early intervention.

Any member of the ISMRM community willing of making the difference by contributing to solve some of the challenges that we face in South America will be potentially interested in this presentation. The objective of this presentation is to give an overview of MRI in South America, focusing the discussion on the example of Brazil. Being such a big and heterogeneous country, we think that Brazil can represent well the issues affecting also other South American countries. and we will propose a challenge to the ISMRM community that is also of interest to other countries in South America.

Firstly we will present some statistics about Brazil: population, density of MRI scanners and prevalence of diseases; to introduce the challenge that we chose for this year, a challenge that we believe can have a high impact in managing some public health issues in South America.

Prevalence of vascular dementia in Brazil and Latin America is higher than in the global north (e.g. US and Europe) probably due to socio-economical factors [1, 2]. Dementia represents a huge economical challenge for Brazil and South America given that in these countries the demographical pyramid is starting to invert. In contrast to other types of dementia, vascular dementia, which mostly affects the lower-income population, can be prevented. Nevertheless research in vascular dementia is not very extensive.

In São Paulo we have access to big MRI data resources from the public health system, given a relatively high density of population and MRI scanners in comparison to other areas of Brazil and other Latin American countries. This data, which represents mostly the lower income target group, can be accessed. It is important to highlight that the distribution of MRI scanners in Brazil is very heterogeneous. While some states have the same ratio of MRI scanners per 100.000 habitants as in some European countries, other states of Brazil still do not reach the minimum recommended by the WHO.

The challenge is to generate a system that can store clinical data known as risk factors for vascular dementia such as for example blood pressure, glycemia, cholesterol together with MRI data (e.g. DICOM). Ideally MRI images should be processed automatically in order to quantify: T2 hyperintensities, ischemic lesions, and hemorrhagic lesions (T2* or SWI), all characteristic of vascular dementia. Machine learning algorithms could then be applied to the data (MRI images and quantitative MRI parameters, together with clinical data) in order to establish a gender and age specific threshold for clinical data at which significant brain changes start to occur.

The final goal would be that, based on this data, action guidelines could be created for patients without access to MRI, but with available clinical data, obtained from simple blood testing. If in a patient the age/gender specific threshold is exceeded, this patient could then be referred to a brain MRI, which would aid an early intervention to prevent the development of vascular dementia.

What would be the best way technically to generate such a system (software, data format, algorithms, MR parameters)? The challenge is open for discussions.

Acknowledgements

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