About functional Magnetic Resonance Imaging:
Functional magnetic resonance imaging (fMRI) is a non-invasive brain imaging technique commonly used by clinicians and neuroscientists to answer questions about the functions of the brain. fMRI can look at the structure and functioning of the brain without needing to inject a test substance or dye. The images obtained can be used to make inferences about brain activity when a task is carried out or when the brain is ‘at rest’. Oftentimes, a research participant is trained to carry out an experimental task (e.g., tapping their fingers, squeezing a ball while he/she is inside the MRI scanner). This is because the task is aimed at activating a set of brain regions or circuits that are revealed after elaborate image pre-processing steps to transform the brain scans into real images (also known as activation images).
Studying resting state allows insight into the global networks and connectivity instead of cognitive tasks. In addition, due to resting tremor and other movement disorders, it is generally not feasible for patients with Parkinson’s disease to perform tasks during MR scanning since movements destroy fMRI (functional MRI) signals. Therefore, we acquire resting state fMRI scans without patients performing any tasks and apply novel approaches with limited preprocess to study the functional connectivity. Via our methods, the connections of the selected regions of interest (ROIs) are revealed and the overall pattern of PD in resting state is investigated.
About Structural Magnetic Resonance Imaging:
These are pictures taken in a series of time to allow clinicians and researchers to non-invasively look at gross anatomical structures in the brain. They can spatially differentiate types of tissues at high resolution.
The traditional way to look at white matter changes is to analyze diffusion tensor imaging (DTI) data in order to characterize the integrity through specific measures such as fractional anisotropy. Probabilistic and deterministic tractography techniques are also widely used to gain insights into the microstructural organization of white matter. However, there are white matter proportions observed in grey matter and the traditional approach might be biased to reveal the microstructural changes from non-white matter tissue. Here we apply a novel method to investigate microstructural changes in Parkinson’s disease.