Vascular patterning of subcutaneous mouse fibrosarcomas expressing individual VEGF isoforms can be differentiated using angiographic optical coherence tomography

Abstract

Subcutaneously implanted experimental tumors in mice are commonly used in cancer research. Despite their superficial location, they remain a challenge to image noninvasively at sufficient spatial resolution for microvascular studies. Here we evaluate the capabilities of optical coherence tomography (OCT) angiography for imaging such tumors directly through the murine skin in-vivo. Data sets were collected from mouse tumors derived from fibrosarcoma cells genetically engineered to express only single splice variant isoforms of vascular endothelial growth factor A (VEGF); either VEGF120 or VEGF188 (fs120 and fs188 tumors respectively). Measured vessel diameter was found to be significantly (p<0.001) higher for fs120 tumors (60.7 ± 4.9μm) compared to fs188 tumors (45.0 ± 4.0μm). The fs120 tumors also displayed significantly higher vessel tortuosity, fractal dimension and density. The ability to differentiate between tumor types with OCT suggests that the visible abnormal vasculature is representative of the tumor microcirculation, providing a robust, non-invasive method for observing the longitudinal dynamics of the subcutaneous tumor microcirculation.

Sub-clinical assessment of atopic dermatitis severity using angiographic optical coherence tomography

“…2.3), thus quantification of vascular morphology was restricted only to data sets which were acquired with the higher resolution. The raw data was processed offline in MATLAB (R2014b -MathWorks) into an angiographic format following a previously described methodology [21,26]. Motion artefacts were suppressed by registering each of the repeat B-scans to the first B-scan captured at each location, using a sub-pixel accurate cross-correlation based algorithm to an accuracy of 100th of a pixel [27].…”

“…Motion artefacts were suppressed by registering each of the repeat B-scans to the first B-scan captured at each location, using a sub-pixel accurate cross-correlation based algorithm to an accuracy of 100th of a pixel [27]. A combined wavelet-FFT filter was then utilized to effectively suppress any remaining motion artefacts with minimal degradation to the underlying vascular information [21,26]. This filter works by considering that a vertical line artefact has a high-frequency component in the horizontal (x) direction and a low frequency component in the vertical (y) direction.…”

“…The image is then inverse Fourier transformed and repackaged together with its corresponding detail, horizontal and diagonal wavelet bands. Further details of this filter can be found in a previous publication [26].…”

Preclinical quantitative in-vivo assessment of skin tissue vascularity in radiation-induced fibrosis with optical coherence tomography

“…1(a) Interestingly, svOCT was unable to detect deeper-located bigger vessels (>100 μm in diameter) in normal skin, possibly due to high scattering of incident OCT light from blood circulating through capillary tufts and from dense hair follicles in the dermal layer. 50 However, in the skin with developed radiation fibrosis, with its thinner epidermis, no tufts, glands, nor hair follicules, bigger vessels located below telangiectasias can be clearly seen [arrows in Figs. 6(c) and 6(d)].…”

Cooperative Three-View Imaging Optical Coherence Tomography for Intraoperative Vascular Evaluation

“…Combined with Doppler flow sensing principle, phase resolved Doppler OCT (PRDOCT) was developed to get the sample structure and flow information simultaneously [14]. Blood flow restoration, 3D thrombosis morphology and stenosis information thus can thus be acquired objectively and quickly using OCT [15,16]. A real-time, detailed imaging methodology of the vasculature after anastomosis procedures can significantly affect patient outcomes [17].…”