qMRI
Quantitative MRI
Typical MRI images have signal intensities that depend on many factors: how much water is present in the imaged voxels, the relaxation behaviour of the water and on the magnetic fields used in the imaging process (i.e. the static, transmit and receive fields).
A more specific approach is to combine the images with signal models to quantify specific tissue properties, e.g. the longitudinal relaxation rate (R1) or a measure of how quickly the signal decays via the effective transverse relaxation rate (R2*).
The image above shows multiple different quantitative MRI parameters, which are obtained using the Multi-Parameter Mapping (MPM) protocol. The red arrows and circles show how anatomical structures can appear very differently depending on the particular tissue parameter that has been quantified. This is because each of the parameters are sensitive to distinct features of the tissue microstructure in different ways.
We have provided these imaging sequences to many different imaging sites around the world so that they too can acquire the same data.
The MPM protocol for quantitative MRI has been used to investigate lots of different aspects of human brain architecture, e.g. healthy aging (like in the figure above adapted from Callaghan et al. (2014) Neuobiol. Aging), development, cognitive neuroscience, and to investigate the relationship between structure and function, even across imaging modalities - see the publications page for more.