Towards In-Vivo X-Ray Nanoscopy (original) (raw)

3D X-Ray imaging of bone tissue from micro to nano scale and associated inverse problems

2015

Imaging bone tissue from the organ to the cellular level is a major goal in bone research to understand, diagnose and predict bone fragility associated to bone disease such as osteoporosis. In this presentation, we show that X-ray CT is particularly well adapted to image bone in 3D up to the nanometer scale. After recalling the principles of 3D CT, we describe advances in bone CT imaging and the needs in associated inverse problems. Clinical X-ray CT is daily used to image skeletal tissue at the organ scale with a spatial resolution of about 0.5mm. However such systems do not permit to image bone micro-architecture made of a complex network of thin trabeculae (thickness about 150 µm). Imaging trabecular bone has been a driving application in the development of X-ray micro-Computerized Tomography (CT) ex-vivo. New High Resolution peripheral Quantitative CT (HR pQCT) systems provide images at voxel size around 100 µm, permitting the investigation of bone micro-structure in vivo [1]. S...

Imaging cells and sub-cellular structures with ultrahigh resolution full-field X-ray microscopy

Our experimental results demonstrate that full-field hard-X-ray microscopy is finally able to investigate the internal structure of cells in tissues. This result was made possible by three main factors: the use of a coherent (synchrotron) source of X-rays, the exploitation of contrast mechanisms based on the real part of the refrac-tive index and the magnification provided by high-resolution Fresnel zone-plate objectives. We specifically obtained high-quality microradiographs of human and mouse cells with 29 nm Rayleigh spatial resolution and verified that tomographic reconstruction could be implemented with a final resolution level suitable for subcellular features. We also demonstrated that a phase retrieval method based on a wave propagation algorithm could yield good subcellular images starting from a series of defocused microradiographs. The concluding discussion compares cellular and subcellular hard-X-ray microradiology with other techniques and evaluates its potential impact on biomedical research.