Understanding tumors and their microenvironment is essential for successful and accurate disease diagnosis. Hyperspectral imaging in VIS-NIR spectral region was used to image benign and malign skin tumors in the head and neck regions of human volunteers. The images were analyzed using five tissue indices (Dawson’s melanin and corrected erythema indices, Huang’s and Ishimaru’s skin oxygenation indices, and tissue water index) to extract tissue parameters important for understanding tumor physiology and morphology. Two examples are presented, one of a benign papillary nevus, and one of a basal cell carcinoma (BCC). The indices show that the nevus has substantially higher melanin index, whereas the BCC has increased erythema index, both oxygenations, and water index. The indices can help with determination and classification of tumors, and provide information about the processes present in the tumorous and healthy tissue.
Significance: Hyperspectral imaging (HSI) has emerged as a promising optical technique. Besides optical properties of a sample, other sample physical properties also affect the recorded images. They are significantly affected by the sample curvature and sample surface to camera distance. A correction method to reduce the artifacts is necessary to reliably extract sample properties.
Aim: Our aim is to correct hyperspectral images using the three-dimensional (3D) surface data and assess how the correction affects the extracted sample properties.
Approach: We propose the combination of HSI and 3D profilometry to correct the images using the Lambert cosine law. The feasibility of the correction method is presented first on hemispherical tissue phantoms and next on human hands before, during, and after the vascular occlusion test (VOT).
Results: Seven different phantoms with known optical properties were created and imaged with a hyperspectral system. The correction method worked up to 60 deg inclination angle, whereas for uncorrected images the maximum angles were 20 deg. Imaging hands before, during, and after VOT shows good agreement between the expected and extracted skin physiological parameters.
Conclusions: The correction method was successfully applied on the images of tissue phantoms of known optical properties and geometry and VOT. The proposed method could be applied to any reflectance optical imaging technique and should be used whenever the sample parameters need to be extracted from a curved surface sample.
Curvature and height corrections were made on hyperspectral images in order to reduce intensity dependence on distance and inclination. The corrections were made by Lambertian cosine law and measured 3D surface of the sample. Image of homogeneous phantom appeared significantly more homogeneous after correction.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.