Hyperspectral imaging is used to collect and process images across the electromagnetic spectrum. The technique is a combination of spectroscopy and 2D or 3D imaging, and it is used to obtain the spectrum for each pixel in the image. Obtaining the spectrum enables hyperspectral imaging to be used for detecting processes, identifying materials, and finding objects.
The technique works by dividing the spectrum into more bands of light than what can be observed by the human eye. The recorded spectra have fine wavelength resolution and cover a large range of wavelengths.
The applications of hyperspectral imaging are vast, which is the reason for its popularity. Common uses include agriculture, food processing, surveillance, and medical. One of the newer applications of the technique is cancer detection, it is a popular method for this due to its minimally invasive, non-contact characteristics. This blog post will discuss how it can be used and some of the breakthroughs the technique has already made.
Detecting Brain Tumours
Brain tumors can often resemble normal neurological tissue, which can make them difficult to detect and identify the borders of a tumor. This is an issue when treating brain tumors, as the borders need to be clear so the surrounding brain tissue is protected.
Hyperspectral imaging has been used to help detect brain tumors, as it has the ability to identify disease conditions based on the chemical composition of the tissue when it is imaged. This provides a precise image of the tumor borders in real-time, which accelerates diagnosis and can improve the removal of a tumor.
Breast Cancer Detection
While it has not yet been successfully used to detect breast cancer in humans, hyperspectral imaging does show promise for this application. Studies have shown that using hyperspectral imaging to detect breast cancer in rats has been successful. The technique was able to differentiate the tumor, muscle, connective tissue, and blood vessels, which suggests the technique has the potential for identifying more effective biopsy locations.
Continuously Variable Bandpass Filters for Hyperspectral Imaging
Hyperspectral Imaging cameras were previously built with prisms and gratings as dispersive elements, which made them very expensive and bulky. As the technique has become more popular, especially in the realm of cancer detection, the cameras need to be smaller and cheaper to provide a cost-effective solution that can be easily transported.
Delta Optical Thin Film has developed Bifrost Continuously Variable Bandpass Filters, which can considerably reduce the weight and size of the camera while providing high resolution, excellent signal to noise ratio, a short measurement time, and high stray light suppression. The filters also provide a higher transmission and a bigger aperture compared to traditional gratings and prisms.