A Survey on Biomarkers for Imaging Modalities

Biomarkers play a critical role in brain tissue classification, providing a way to classify the different types of tissues of the brain into gray matter (GM), white matter (WM), and Cerebro Spinal Fluid (CSF). Image modalities like Diffusion Tensor Imaging, Magnetic Resonance Imaging, Diffusion Weighted Imaging, Higher Angular Resolution Diffusion Imaging HARDI and Diffusion Kurtosis Imaging (DKI) are proving to be quite helpful in discerning abnormal patterns in the brain thereby providing an accurate diagnosis in the neurogenerative diseases like Multiple Sceloris, Cancer, Ischemia and many others. However, when it comes to detecting multiple paths and orientations, we require complex modalities that give better and correct results in terms of predicting the axonal pathways of the brain, hence there is a need to switch to modalities like HARDI and DKI. Higher-order angular resolution imaging (HARDI) provides more detailed and accurate images of the brain tissue compared to traditional imaging methods, and the use of biomarkers in HARDI can improve the accuracy and precision of brain tissue classification. By evaluating the kurtosis of the diffusion process, DKI conveys additional details regarding the non-Gaussian behavioral patterns of water diffusion. The existing modalities are all studied and this research provides a survey on the biomarkers associated with the modalities. The use of biomarkers in HARDI is critical for improving the accuracy and precision of brain tissue classification, for better visualization of disease-specific changes, for better monitoring of therapeutic response, and for improving the results. The work presented in this paper is an overview about the biomarkers available for the various modalities.