Automated segmentation and enhancement of optical coherence tomography-acquired images of rodent brain

Abstract

Background Optical coherence tomography (OCT) is a non-invasive optical imaging method that has proven useful in various fields such as ophthalmology, dermatology and neuroscience. In ophthalmology, significant progress has been made in retinal layer segmentation and enhancement of OCT images. There are also segmentation algorithms to separate epidermal and dermal layers in OCT-acquired images of human skin. New Method We describe simple image processing methods that allow automatic segmentation and enhancement of OCT images of rodent brain. Results We demonstrate the effectiveness of the proposed methods for OCT-based microangiography (OMAG) and tissue injury mapping (TIM) of mouse cerebral cortex. The results show significant improvement in image contrast, delineation of tissue injury, allowing visualization of different layers of capillary beds. Comparison with existing methods Previously reported methods for other applications are yet to be used in neuroscience due to the complexity of tissue anatomy, unique physiology and technical challenges. Conclusions OCT is a promising tool that provides high resolution in vivo microvascular and structural images of rodent brain. By automatically segmenting and enhancing OCT images, structural and microvascular changes in mouse cerebral cortex after stroke can be monitored in vivo with high contrast.

Whole-body positional manipulators for ocular imaging of anaesthetised mice and rats: a do-it-yourself guide

“…[20][21][22] The high resolution of third-generation spectral-domain OCT devices renders in vivo retinal imaging in mice and rats possible, gaining an increasing importance in ophthalmological and neurological preclinical research. [23][24][25][26][27][28][29][30][31][32][33] The obtained results are in good accordance with histological sections of the animals' retinae. 34 The application of OCT technology in rodent models, however, is still challenging, mainly because of the small size of the rodents' eyes.…”

Cerebral capillary velocimetry based on temporal OCT speckle contrast

“…A fiber-based 1340nm spectral domain OCT system [24] was used for the capillary velocimetry experiments. The light source was a superluminescent diode (LS2000C, Thorlabs Inc.) with a spectral bandwidth of 110nm at the full-wavelength width at half maximum, yielding the axial (depth) resolution of ~7μm in tissue.…”

“…The body temperature of mouse was maintained at 36.8°C by a heating blanket on the frame whose temperature was controlled by a homeothermic monitoring system (50-7220F, Harvard Apparatus) that continually monitored the body temperature using rectal insertion of a temperature-sensing probe. Under anesthesia, the mice received open skull craniotomy [24], where a 4mm × 4mm area of the skull over the somatosensory cortex in right hemisphere was removed along with the dura and then the exposed somatosensory cortex was covered with a 5-mm-diameter transparent glass coverslip. The cranial window covers the territories supplied by the anterior cerebral artery (ACA) and middle cerebral artery (MCA), and anastomoses.…”

Optical coherence tomography for precision brain imaging, neurosurgical guidance and minimally invasive theranostics

“…Recent development of OCT-based angiography has started to shed some new light on cerebral hemodynamics in neuroscience. Baran et al demonstrated the effectiveness of proposed automatic image segmentation and enhancement methods for OCT-based microangiography (OMAG) and tissue injury mapping (TIM) in a mouse cerebral cortex (50,51).…”