Kazuyuki Hyodo

First Application of X-ray Refraction-based Computed Tomography to a Biomedical Object

Abstract We have developed X-ray refraction-based computed tomography (CT) that is able to visualize soft tissue in between hard tissue. The experimental system consists of Si(220) diffraction double-crystals and is called the DEI (diffraction-enhanced imaging) method, in which the object is located between the crystals and a CCD camera to acquire data as 360 X-ray images. The X-ray energy used was 17.5 keV. The algorithm used to reconstruct CT images was developed by A. Maksimenko and colleagues. We successfully visualized articular cartilage and the distribution of bone marrow, which are inner structures. Our method has much higher contrast compared to the conventional absorption-based CT system.

Attempt at Two-Dimensional Mapping of X-ray Fluorescence from Breast Cancer Tissue

A world first two-dimensional mapping of X-ray fluorescence from an invasive papillary carcinoma containing three kinds of metal elements that by white radiation has been obtained. Carcinoma shows intense Ca K X-rays, while normal tissue including stroma, shows no such Ca X-ray signals within experimental precision, but even shows reasonable Fe and Zn K X-ray intensity. This has extremely good correspondence to an X-ray dark-field (X-DF) image taken using a Laue angular analyzer. This fact may suggest an idea that carcinoma may attract Ca atoms better than Fe and Zn atoms, which are involved more in normal tissue.

Transmission Electron Microscopy Cross-Sectional Observation on Mechanically and Chemically Lapped Si (111) Surfaces

The (111) surfaces of Si single crystals, mechanically lapped by fine abrasives with different particle size or chemically etched, are observed from the cross-sectional direction by transmission electron microscopy (TEM). On the mechanically lapped surface the defect layers of several µm in thickness, containing blocks, grains and cracks along nearly {100}, {110} {111} and {112}, are formed. The size of grains as well as the misorientation between grains increases with increase of the particle size of abrasives. On the chemically etched surface, on the other hand, the defect density is so low that the crystal near the surface seems almost perfect. The prominent enhancement of X-ray integrated intensity from mechanically lapped surfaces can be related to the misorientation between grains.

Nondestructive visual search for fossils in rock using X-ray interferometry imaging

Fossils inside rock have been clearly visualized utilizing an X-ray interferometer. Two types of clear images are obtained, one involves phase contrast in interference beams and the other involving refraction contrast in forward-diffracted beams. 2D monochromatic synchrotron X-ray radiation with a beam size of 10 mm×10 mm and a photon energy of 35 keV was used. Using a stereographic pair of X-ray images, the locations of fossils inside rock can easily be determined with a precision of 0.5 mm. This method can be a powerful nondestructive tool in the fields of paleontology and paleobiology to discover and locate fossils and trace fossils inside rock.

Application of x-ray computed tomography based on the refraction contrast to biomedicine

We have developed X-ray refraction based computed tomography (CT) which is able to visualize soft tissue in between hard tissue. The experimental system consists of Si(220) diffraction double-crystals called the DEI (diffraction-enhanced imaging) method, object locating in between them and a CCD camera to acquire data of 900 x-ray images. The x-ray energy used was 17.5 keV. The algorithm used to reconstruct CT images has been invented by A. Maksimenko et al.. We successfully visualized calcification and distribution of breast cancer nest which are the inner structure. It has much higher contrast which in comparison with the conventional absorption based CT system.

An X-Ray Trichrome Imaging 'Trinity': Absorption, Phase-Interference and Angle-Resolved Contrast

A newly designed 100-mm-long X-ray trichrome optics for imaging has been proposed. Its working X-ray photon energy is 35 keV. Since this optics has two alternate mirrors, it can simultaneously supply three types of images: absorption, phase-interference and angle-resolved contrast for a sample space of 7 mm width. Examples of imaging by this novel X-ray interferometer in medicine, biology and material science are presented.

Visualization of soft tissues by highly sensitive X-ray crystal analyzer-based multi diffraction enhanced imaging

In this paper, we propose a novel multi diffraction enhanced imaging (MDEI) technique to improve contrast resolution owning to the sharp rise of the reflectivity curve and high contrast-to-noise ratio (CNR). MDEI is derived from the diffraction enhanced imaging (DEI) technique. Here, DEI and MDEI phase contrast tomograms are compared. The results show that MDEI offers higher contrast resolution, while DEI has higher spatial resolution. This study provided indications for developments and applications of X-ray crystal analyzer-based imaging to obtain a higher contrast resolution.

2D and 3D Refraction Based X‐ray Imaging Suitable for Clinical and Pathological Diagnosis

The first observation of micro papillary (MP) breast cancer by x‐ray dark‐field imaging (XDFI) and the first observation of the 3D x‐ray internal structure of another breast cancer, ductal carcinoma in‐situ (DCIS), are reported. The specimen size for the sheet‐shaped MP was 26 mm × 22 mm × 2.8 mm, and that for the rod‐shaped DCIS was 3.6 mm in diameter and 4.7 mm in height. The experiment was performed at the Photon Factory, KEK: High Energy Accelerator Research Organization. We achieved a high‐contrast x‐ray image by adopting a thickness‐controlled transmission‐type angular analyzer that allows only refraction components from the object for 2D imaging. This provides a high‐contrast image of cancer‐cell nests, cancer cells and stroma. For x‐ray 3D imaging, a new algorithm due to the refraction for x‐ray CT was created. The angular information was acquired by x‐ray optics diffraction‐enhanced imaging (DEI). The number of data was 900 for each reconstruction. A reconstructed CT image may include ductus lact...

First attempt at 3d x-ray visualization of DCIS (ductal carcinoma in situ) due to refraction contrast – in good relation to pathological view

First 3D X-ray internal observation of DCIS (ductal carcinoma in-situ) is reported. Its rod shaped specimen with 3.6 mm in diameter and 4.7 mm in height was punched out to have successfully observed by using a newly made algorithm due to refraction for x-ray CT. Its data was acquired by the x-ray optics DEI (diffraction-enhanced imaging). Data of 900 projections with interval of 0.2 degrees was used at Photon Factory, KEK in Tsukuba. A reconstructed CT image may include clearly revealed ductus lactiferi, microcalcification and other structure. The voxel resolution is approximately 50 μm by the present instrumental condition. This modality could open up an x-ray pathological diagnosis.

A Test of an X-Ray Quatrochrome Interferometer for Simultaneous Observation of Images Due to Dark- and Bright-Field, Phase-Interference and Absorption Contrasts

We developed new notdestructive observation method that simultaneously provides four different types of contrast: dark- and bright-fields and absorption and phase-interferences. The first two contrasts originate from the deflection of X-ray on the boundaries of the object and nonhomogeneities of its internal structure. Although the first two contrasts are different manifestations of the so-called angle-resolved contrast they proved to be interesting independent of each other. A new X-ray optical device was realized. The device had dimensions of approximately 60 mm x 40 mm x 30 mm so that the view size available was approximately 4 mm x 10 mm. The X-ray energy used was 36.0 keV at Photon Factorys BL14B using the vertically polarized synchrotron radiation from the vertical wiggler that runs at 5 T. The exposure for each picture was approximately 60 s.