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Third generation synchrotron radiation sources are an invaluable tool in biomedical research. Their high flux, coherence and tunability are key in the development of novel pre-clinical techniques, ranging from imaging diagnostics to treatment therapies.
In a classical radiograph, images are formed because of the different absorption of the tissues to the x-rays. But absorption of x-rays is just one of the consequences of the many physical interactions of the x-rays with the matter. Much of these interactions are an useful source of information about the biological tissues, if their effects are properly recorded. Phase contrast, analyzer based or dark-field imaging take advantage of the phase shift of the x-rays. Using the phase instead of the absorption to produce images not only the contrast can be greatly enhanced but also the visibility of fine details in biological tissues.
In diagnostics radiology, the scattering of the x-rays from the tissues is regarded as a nuisance, blurring the images and reducing the contrast. However, the scattered x-rays bears useful information about the structures and pathological state of the biological tissues. Every tissue presents a characteristic scattering signal, which can be used to explore the tissue composition as well as its potential pathologies. Collagen in the breast and the in skin, or myelin in the brain are just some examples of molecules that suffer structural modifications when the tissues present a disease.
Combination of the phase imaging systems and the scattering knowledge of the tissues, new imaging diagnostic tools are being developed in synchrotrons, which not only increase the visibility of tissues but also the depiction of pathologies.
These methods and techniques might be translated to clinical environment thanks to the so called table-top synchrotron sources.
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