Decreased light attenuation in cerebral cortex during cerebral edema detected using optical coherence tomography

Abstract

Cerebral edema develops in response to a variety of conditions, including traumatic brain injury and stroke, and contributes to the poor prognosis associated with these injuries. This study examines the use of optical coherence tomography (OCT) for detecting cerebral edema in vivo. Three-dimensional imaging of an in vivo water intoxication model in mice was performed using a spectral-domain OCT system centered at 1300 nm. The change in attenuation coefficient was calculated and cerebral blood flow was analyzed using Doppler OCT techniques. We found that the average attenuation coefficient in the cerebral cortex decreased over time as edema progressed. The initial decrease began within minutes of inducing cerebral edema and a maximum decrease of 8% was observed by the end of the experiment. Additionally, cerebral blood flow slowed during late-stage edema. Analysis of local regions revealed the same trend at various locations in the brain, consistent with the global nature of the cerebral edema model used in this study. These results demonstrate that OCT is capable of detecting in vivo optical changes occurring due to cerebral edema and highlights the potential of OCT for precise spatiotemporal detection of cerebral edema.

Cerebral edema detection in vivo after middle cerebral artery occlusion using swept-source optical coherence tomography

“…They were then dried in a gravity oven at 100°C for 24 h to obtain their corresponding dry weight. 21 The percent of BWC was calculated with the following formula:…”

“…They used spectral-domain optical coherence tomography (SD-OCT) to detect OAC in different parts of the cerebral cortex and found that the average OAC of the cerebral cortex gradually decreased as cerebral edema progressed. 21 The research team conducted another study that explored a focal model of edema in a mouse model of traumatic brain injury and observed changes in scatter correlated with edema formation around the impact site.…”

Automated, Depth-Resolved Estimation of the Attenuation Coefficient From Optical Coherence Tomography Data

“…Several studies have shown that using OCT to quantify the local attenuation coefficient is relevant to diagnostic, classification, and surveillance applications. For example, measurements of the attenuation coefficient have been implicated in atherosclerotic plaque characterization [1], renal cancer diagnosis [2], glucose diffusion measurement [3], bladder cancer tumor staging [4], burn scar assessment [5], ovarian tissue collagen content quantification [6], cerebral edema detection [7], and glaucoma diagnosis and surveillance [8]. …”

Characterizing the optical properties of human brain tissue with high numerical aperture optical coherence tomography

“…This simple model has proven to be useful in detecting cancerous tissues in skin, bladder and brain [1][2][3], monitoring blood glucose concentration [4], characterizing atherosclerosis plaques [5,6] and correlating collagen content with histological staining [7]. Recently, quantification of the attenuation coefficient has been adopted in brain imaging [8] to follow neurological development in mouse models [9], to detect borders of brain tumors in human specimens [3,10], and to examine the physiological alterations in edema [11]. At imaging depths up to ~1mm, typically only a few scattering lengths deep in the tissue, it is generally valid to assume the single scattering Beer's law where detected photons only scattering once within the tissue.…”