Projects POR-FESR Regione Lazio

FISASMEM – Physiology of ageing: development of quantitative MRI methods

2021-2023 Lazio Region POR-FESR A0375-2020-36648

The characterisation of ageing is important for social welfare and the devastating impact of some neurological diseases associated with ageing. Functional magnetic resonance imaging (fMRI) is an investigative tool that captures the deterioration of human brain network function associated with ageing and neurodegeneration. However, fMRI suffers from limitations due to the variation with age of noise of physiological origin, which is a confounding factor difficult to separate from the effect of neuronal origin. This project aims to address this scientific problem, which has important industrial repercussions in the health and biomedical industry, by characterising the physiological origin of fMRI noise in ageing and in the early stages of neurodegeneration in terms of variations in vascular reactivity and micro-movements and developing appropriate mitigation methods.

The project was funded by the Lazio Region with POR FESR LAZIO 2014 – 2020 A0375-2020-36648, POR A0375E0085 (€ 149089,39)


Brain ageing is characterized by a decline in vascular function, in particular within the microvasculature, which can be observed as a reduction in cerebral blood flow (CBF), cerebrovascular reactivity (CVR) and rate of oxygen consumption (CMRO2).

Within this project, we developed a protocol for CVR mapping using three different functional contrasts within a single session (total acquisition time: 20 minutes). Cerebrovascular reactivity is a measure of the dilatory or constrictive capacity of blood vessels upon vasoactive stimuli and it is generally assessed using a single fMRI contrast, which is usually BOLD (blood oxygenation level-dependent). However, BOLD is not quantitative as it depends on baseline physiological parameters, which may vary among subjects, and the field strength employed, making the data acquired at e.g. 1.5 T, 3 T and 7 T not directly comparable.

In our protocol, apart from a BOLD acquisition, two more sequences were added to obtain quantitative information and a deeper characterization of CVR: ASL (arterial spin labeling), sensitive to CBF changes, and VASO (vascular space occupancy), sensitive to cerebral blood volume (CBV) changes.

An example of a multi-contrast acquisition obtained using our protocol is shown in the figure below. This characterization is particularly novel since no other studies report a single-session mapping of these three contrasts upon a vasodilatory stimulus.