Analysis of spatial variability in hyperspectral imagery of the uterine cervix in vivo

Abstract

General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ABSTRACT The use of fluorescence and reflectance spectroscopy in the analysis of cervical histopathology is a growing field of research. The majority of this research is performed with point-like probes. Typically, clinicians select probe sites visually, collecting a handful of spectral samples. An exception to this methodology is the Hyperspectral Diagnostic Imaging (HSDI ® ) instrument developed by Science and Technology International. This non-invasive device collects contiguous hyperspectral images across the entire cervical portio. The high spatial and spectral resolution of the HSDI instruments make them uniquely well suited for addressing the issues of coupled spatial and spectral variability of tissues in vivo. Analysis of HSDI data indicates that tissue spectra vary from point to point, even within histopathologically homogeneous regions. This spectral variability exhibits both random and patterned components, implying that point monitoring may be susceptible to significant sources of noise and clutter inherent in the tissue. We have analyzed HSDI images from clinical CIN (cervical intraepithelial neoplasia) patients to quantify the spatial variability of fluorescence and reflectance spectra. This analysis shows the spatial structure of images to be fractal in nature, in both intensity and spectrum. These fractal tissue textures will limit the performance of any point-monitoring technology.

Portable, low-cost multispectral imaging system: design, development, validation, and utilization

“…Indeed, most systems that make such measurements that are in clinical use today are built on a cart. 20,21,38 The small-form factor, light weight, and low power nature of our system allow it to be portable, carried by physicians who move between patients beds or between clinics. If successfully translated and productized, it can have a profound effect on clinical care.…”

“…16 Despite the advantages of multi-and hyperspectral imaging in obtaining clinically relevant information, few commercial systems that can assess oxygen saturation in images exist, and those that are FDA-cleared cost upward of $40,000 and are often difficult to use. [17][18][19] In contrast to these expensive, cart-filled systems from 15 years ago, 20,21 the revolution in consumer electronics has made low-cost cameras and LEDs ubiquitous, bringing down the costs significantly. Several groups and companies have attempted to build a low-cost multispectral imaging system that can quantify scattering and absorption in the tissue, [22][23][24] including some based on LED illumination at various wavelengths, [25][26][27][28] in which spectral data were validated against spectral measurements from existing systems.…”