Measuring myelin content and cell density in the human brain using optical coherence tomography

Serial Sectioning Optical Coherence Tomography(serial sectioning OCT) has been widely used to investigate the structural and pathological features of brain samples. OCT is an optical imaging technique that provides both the 3D structure of the tissue as well as the optical properties including the scattering coefficient (μs) and back-scattering coefficient (μb). Serial sectioning OCT allows the reconstruction of distortion-free volumetric images at high contrast and high resolution, which has proven to be useful for the detection of cancerous tissue boundaries, visualizing 3D vascular structures and measuring neuron density. The tissue optical properties extracted from the OCT depth profile has been shown to be related to myelin content and neuron density. However, no quantitative correlation of the tissue optical properties with myelin content and neuron density has been reported. Establishing a quantitative relationship will potentially benefit the segmentation of anatomical layers and the characterization of demyelination and neuron loss, which are related to neurological diseases such as Alzheimer’s and Chronic Traumatic Encephalopathy(CTE). Here, we demonstrate using block-face imaging with optical coherence tomography (OCT) to quantitatively measure myelin content and neuron density in the human brain. By correlating the OCT measurements of tissue optical properties with the ground truth of myelin content and neuron density provided by histology, we found that the scattering coefficient possesses a linear relationship with the myelin content across different regions of the human brain, while the neuron density only slightly modulate the overall tissue scattering properties