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The basic idea of X-ray dark-field imaging (XDFI), first presented in 2000, was based on the concepts used in an X-ray interferometer. In this article, we review 20 years of developments in our theoretical understanding, scientific instrumentation, and experimental demonstration of XDFI and its applications to medical imaging. We first describe the concepts underlying XDFI that are responsible for imparting phase contrast information in projection X-ray images. We then review the algorithms that can convert these projection phase images into three-dimensional tomographic slices. Various implementations of computed tomography reconstructions algorithms for XDFI data are discussed. The next four sections describe and illustrate potential applications of XDFI in pathology, musculoskeletal imaging, oncologic imaging, and neuroimaging. The sample applications that are presented illustrate potential use scenarios for XDFI in histopathology and other clinical applications. Finally, the last section presents future perspectives and potential technical developments that can make XDFI an even more powerful tool.

Purpose This paper describes and experimentally validates a methodology for improving contrast and spatial resolution of the x-ray dark-field imaging (XDFI) by cutting the monochromator-collimator asymmetrically and thinning the Laue angle analyzer. Methods We measure the spatial resolution of our XDFI setup using a test object consisting of wolfram tungsten meshes and compare it with the theoretical prediction. Using x-ray dark-field computed tomography of breast cancer specimens (lobular carcinoma in situ), we demonstrate that the resolution of XDFI is sufficient for histopathologic analysis. Results Our experimental results show that the overall spatial resolution of XDFI can be improved by approximately a factor of 2 when these modifications are implemented. The reconstructed images of breast cancer specimens provide sufficient details for radiologic histopathology. Conclusions By cutting the monochromator-collimator and thinning the Laue angle analyzer, XDFI can achieve the resolution sufficient for radiologic histopathology.

Purpose: High-resolution cardiac imaging and fiber analysis methods are required to understand cardiac anatomy. Although refraction-contrast x-ray CT (RCT) has high soft tissue contrast, it cannot be commonly used because it requires a synchrotron system. Microfocus x-ray CT (μCT) is another commercially available imaging modality. Approach: We evaluate the usefulness of μCT for analyzing fibers by quantitatively and objectively comparing the results with RCT. To do so, we scanned a rabbit heart by both modalities with our original protocol of prepared materials and compared their image-based analysis results, including fiber orientation estimation and fiber tracking. Results: Fiber orientations estimated by two modalities were closely resembled under the correlation coefficient of 0.63. Tracked fibers from both modalities matched well the anatomical knowledge that fiber orientations are different inside and outside of the left ventricle. However, the μCT volume caused incorrect tracking around the boundaries caused by stitching scanning. Conclusions: Our experimental results demonstrated that μCT scanning can be used for cardiac fiber analysis, although further investigation is required in the differences of fiber analysis results on RCT and μCT.

We present a depth super-resolved 3D imaging method for inspection of defects in walls using terahertz swept-source optical coherence tomography. A depth profile analysis based on an annihilating filter method with noise reduction was applied for signal processing, and the results were compared with those of conventional inverse fast Fourier transform (IFFT) analysis. To evaluate the depth resolution, we measured a plastic step sample with 1 mm thickness, and its front and back surfaces were discriminated. This is corresponding to about 1/3 of the theoretical depth resolution of the conventional IFFT analysis. Moreover, we demonstrated 3D imaging of the void with a 10 mm width behind a ceramic tile and succeeded in reconstructing a significantly sharper cross-sectional void image than in the conventional analysis.

Although the nipple is clinically relevant, little is known about the spatial location of the main ducts in the nipple. A controversy still exists as to whether the main ducts are interconnected or not within the nipple. Most previous studies have suggested that such anastomosis is rare between the main ducts in the nipple, but it remains difficult to examine whether the particular individual case does have such anastomoses or not because reconstructing the 3-D structure from the 2-D pathological images generally requires great laborious efforts. In the research, we directly reconstructed the 3-D structure of milk ducts in human nipples using the refraction-contrast X-ray computed tomography based on emerging x-ray dark field imaging optics (XDFI-CT), which allows visualizing the precise 3-D structure of biological soft tissue as well as the stained pathological image.

We construct a terahertz swept source optical coherence tomography system using a continuous-wave diode multiplier source in the 600-GHz band for defect inspection in multilayer objects and evaluate its performance. Using this system, we image a multilayer plastic sample to demonstrate the effectiveness of nondestructive three-dimensional imaging. To enhance the depth resolution, we apply an annihilating filter to the analysis and confirm that two surfaces of a 1-mm-thick plastic plate can be resolved. In addition, the repeatability of measured thicknesses is 0.22 mm. These values are approximately one-half and one-tenth of the resolution achievable by conventional Fourier analysis, respectively.

In recent years, cell and tissue therapy in regenerative medicine have advanced rapidly towards commercialization. However, conventional invasive cell quality assessment is incompatible with direct evaluation of the cells produced for such therapies, especially in the case of regenerative medicine products. Our group has demonstrated the potential of quantitative assessment of cell quality, using information obtained from cell images, for non-invasive real-time evaluation of regenerative medicine products. However, image of cells in the confluent state are often difficult to evaluate, because accurate recognition of cells is technically difficult and the morphological features of confluent cells are non-characteristic. To overcome these challenges, we developed a new image-processing algorithm, heterogeneity of orientation (H-Orient) processing, to describe the heterogeneous density of cells in the confluent state. In this algorithm, we introduced a Hessian calculation that converts pixel intensity data to orientation data and a statistical profiling calculation that evaluates the heterogeneity of orientations within an image, generating novel parameters that yield a quantitative profile of an image. Using such parameters, we tested the algorithm's performance in discriminating different qualities of cellular images with three types of clinically important cell quality check (QC) models: remaining lifespan check (QC1), manipulation error check (QC2), and differentiation potential check (QC3). Our results show that our orientation analysis algorithm could predict with high accuracy the outcomes of all types of cellular quality checks (>84% average accuracy with cross-validation).

Despite the growing numbers of successful applications in regenerative medicine, biotechnologies for evaluating the quality of cells remain limited. To evaluate the cultured cells non-invasively, image-based cellular assessment method holds great promise. However, although there are various image-processing algorithms, very few studies have focused to prove the effectiveness of phase contrast images with risk assessment example that reflects actual difficulties in regenerative medicine products. In this study, we developed a simple image-processing method to recognize the number of dividing cells in time-course phase-contrast microscopic images, and applied this method to assess the irregular proliferation behavior in normal cells. Practically, as a model, rapid proliferating human fibrosarcoma cells were mixed in normal human fibroblasts in the same culture dish, and their sarcoma existence was evaluated. As a result, the existence of sarcoma population in normal cell sample could be feasibly detected within earliest period of cell culture by their irregular rise of accumulated counts of dividing cells. Our image-processing technique also illustrates the technical effectiveness of combining intra-frame and inter-frame image processing to accurately count only the dividing cells. Our concept of focused counting of dividing cells shows a successful example of image-based analysis to quickly and non-invasively monitor the regular state of regenerative medicine products.

We propose a novel computed tomography (CT) imaging method based on phase-contrast using a continuous wave (CW) THz source with a frequency of 0.54 THz. The system acquires phase-shift by phase modulation technique using Mach-Zehnder interferometer at each data point, and collects projections of the phase-shift from multiple directions over 360 degrees to finally reconstruct a spatial distribution of refractive index. We construct a preliminary system for proof of the concept, and perform an imaging experiment using a polystyrene foam phantom. It was shown that the THz-CT produces an artifact-free and quantitative reconstruction at a spatial resolution of a few mm.

We propose a pinhole-based fluorescent x-ray computed tomography (p-FXCT) system with a 2-D detector and volumetric beam that can suppress the quality deterioration caused by scatter components. In the corresponding p-FXCT technique, projections are acquired at individual incident energies just above and below the K-edge of the imaged trace element; then, reconstruction is performed based on the two sets of projections using a maximum likelihood expectation maximization algorithm that incorporates the scatter components. We constructed a p-FXCT imaging system and performed a preliminary experiment using a physical phantom and an I imaging agent. The proposed dual-energy p-FXCT improved the contrast-to-noise ratio by a factor of more than 2.5 compared to that attainable using mono-energetic p-FXCT for a 0.3 mg/ml I solution. We also imaged an excised rat’s liver infused with a Ba contrast agent to demonstrate the feasibility of imaging a biological sample.

Synchrotron-based XRD spectra from rat bone of different age groups (w, 56 w and 78w), lumber vertebra at early stages of bone formation, Calcium hydroxyapatite (HAp) [Ca10(PO4)6(OH)2] bone fill with varying composition (60% and 70%) and bone cream (35-48%), has been acquired with 15keV synchrotron X-rays. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15keV X-rays (λ=0.82666 A0). Diffraction data were quantitatively analyzed using the Rietveld refinement approach, which allowed us to characterize the structure of these samples in their early stages. Hydroxyapatite, received considerable attention in medical and materials sciences, since these materials are the hard tissues, such as bone and teeth. Higher bioactivity of these samples gained reasonable interest for biological application and for bone tissue repair in oral surgery and orthopedics. The results obtained from these samples, such as phase data, crystalline size of the phases, as well as the degree of crystallinity, confirm the apatite family crystallizing in a hexagonal system, space group P63/m with the lattice parameters of a=9.4328A and c=6.8842A (JCPDS card #09-0432). Synchrotron-based XRD patterns are relatively sharp and well resolved and can be attributed to the hexagonal crystal form of hydroxyapatite. All the samples were examined with scanning electron microscope at an accelerating voltage of 15kV. The presence of large globules of different sizes is observed, in small age groups of the rat bone (8w) and lumber vertebra (LV), as distinguished from, large age groups (56 and 78w) in all samples with different magnification, reflects an amorphous phase without significant traces of crystalline phases. Scanning electron microscopy (SEM) was used to characterize the morphology and crystalline properties of Hap, for all the samples, from 2 to 100μm resolution.

Purpose The assessment of retinal nerve fiber layer defects (RNFLDs) is a useful part of glaucoma care. Here, we obtained en-face images of retinal layers below the inner limiting membrane (ILM) with swept source-optical coherence tomography (SS-OCT), and measured RNFLD angle with new software. Methods This study included 105 eyes of 105 normal tension glaucoma (NTG) patients (age, 59.8 ± 13.2). Exclusion criteria were best-corrected visual acuity 28 mm, non-glaucoma ocular disease, and systemic disease affecting the visual field. We obtained 12 x 9 mm 3D volume scans centered on the macula with SS-OCT (DRI OCT-1, Topcon), and from these scans, created 3 averaged en-face images, each comprising 7 horizontal en-face images (total thickness: 18.2 μm). We labeled these averaged images, according to their depth below the ILM, as en-face images 1 (shallowest), 2 (middle) and 3 (deepest). In each image, a circle was drawn centered on the disc, with a radius of half the distance between the centers of the disc and macula. The investigator marked points where the edge of the RNFLD intersected this circle, and RNFLD angle (RNFLDA) was calculated with new software. Finally, we analyzed the association between RNFLDA, cpRNFLT, weighted RGC count (wrgc) and Humphrey field analyzer (HFA)-measured mean deviation (MD) and hemifield total deviation (TD), both overall and in each hemifield. Results En-face image 2 had the highest interclass reproducibility for measuring RNFLDA (intra-rater intraclass correlation coefficient (ICC): 0.988, inter-rater ICC: 0.962). The correlation coefficients with RNFLDA were: HFA MD, -0.60; superior TD, -0.73; inferior TD, -0.69; overall cpRNFLT, -0.27; superior hemifield cpRNFLT, -0.39; and inferior hemifield cpRNFLT, -0.53 (all p

Images of terrestrial and marine invertebrates (snails and bivalves) have been obtained by using an X-ray phase-contrast imaging technique, namely, synchrotron-based diffraction-enhanced imaging. Synchrotron X-rays of 20, 30 and 40 keV were used, which penetrate deep enough into animal soft tissues. The phase of X-ray photons shifts slightly as they traverse an object, such as animal soft tissue, and interact with its atoms. Biological features, such as shell morphology and animal physiology, have been visualized. The contrast of the images obtained at 40 keV is the best. This optimum energy provided a clear view of the internal structural organization of the soft tissue with better contrast. The contrast is higher at edges of internal soft-tissue structures. The image improvements achieved with the diffraction-enhanced imaging technique are due to extinction, i.e., elimination of ultra-small-angle scattering. They enabled us to identify a few embedded internal shell features, such as the origin of the apex, which is the firmly attached region of the soft tissue connecting the umbilicus to the external morphology. Diffraction-enhanced imaging can provide high-quality images of soft tissues valuable for biology.

Images of the cork used for wine and other bottles are visualized with the use of diffraction-enhanced imaging (DEI) technique. Present experimental studies allowed us to identify the cracks, holes, porosity, and importance of soft-matter (soft-material) and associated biology by visualization of the embedded internal complex features of the biological material such as cork and its microstructure. Highlighted the contrast mechanisms above and below the K-absorption edge of iodine and studied the attenuation through a combination of weakly and strongly attenuating materials.

Low crystalline B-type carbonate apatite (CO3Ap) block was fabricated by compositional transformation based on dissolution–precipitation reaction using microporous low crystalline calcite block as a precursor. In other words, microporous low crystalline calcite block prepared by carbonation of Ca(OH)2 compact was phosphoridated by exposing to 1 mol·dm−3 Na2HPO4 solutions at 60°C for 14 days. XRD, FT-IR and SEM analysis showed that calcite block completely transformed into B-type CO3Ap keeping its macroscopic morphology. Diametral tensile strength of the low-crystalline B-type CO3Ap block was approximately 5.4 MPa, and this value was much higher when compared with the low-crystalline calcite block, 0.73 MPa. Low crystalline B-type CO3Ap block fabricated in this method could be an ideal bone replacement due to its close similarity in its inorganic chemical composition and crystallinity to bone.

Synchrotron-based scattered radiation form low-contrast phantom materials prepared from polyethylene, polystyrene, nylon, and Plexiglas is used as test objects in X-ray CT was examined with 8, 10 and 12 keV X-rays. These phantom materials of medical interest will contains varying proportions of low atomic number elements. The assessment will allowed us to estimate the fluorescence to total scattered radiation. Detected the fluorescence spectra and the associated scattered radiation from calcium hydroxyapatite phantom with 8, 10 and 12 keV synchrotron X-rays. Samples with Bonefil (60% and 70% of calcium hydroxyapatite) and Bone cream (35 approximately 45% of calcium hydroxyapatite), were used. Utilized the X-ray micro-spectroscopy beamline facility, X27A, available at NSLS, BNL, USA. The primary beam with a spot size of the order of approximately 10 mum, has been used for focusing. With this spatial resolution and high flux throuput, the synchrotron-based scattered radiation from the phantom materials were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector.

In this study, synchrotron-based micro-beam was utilized for elemental mapping of a small animal shell. A thin X-ray spot of the order of approximately 10microm was focused on the sample. With this spatial resolution and high flux throughput, the X-ray fluorescent intensities for Ca, Mn, Fe, Ni, Zn, Cr and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive HpGe detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping and generated elemental maps at 8, 10 and 12keV. All images are of 10microm resolution and the measurement time was 1s per point. The accumulation of trace elements was investigated from the soft-tissue in small areas. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other trace elements.

Using X-ray fluorescent computed tomography (XFCT), the in vivo and ex vivo cerebral distribution of a stable-iodine-labeled cerebral perfusion agent, iodoamphetamine analog (127I-IMP), has been recorded in the brains of mice. In vivo cerebral perfusion in the cortex, hippocampus and thalamus was depicted at 0.5 mm in-plane spatial resolution. Ex vivo XFCT images at 0.25 mm in-plane spatial resolution allowed the visualisation of the detailed structures of these regions. The quality of the XFCT image of the hippocampus was comparable with the 125I-IMP autoradiogram. These results highlight the sensitivity of XFCT and its considerable potential to evaluate cerebral perfusion in small animals without using radioactive agents.

Hyoid bone fracture is very rare because the hyoid bone is anatomically movable and protected by the mandible, cervical vertebrae, and clavicle. We report a case of jaw fractures with a hyoid bone fracture. The patient was a 56-year-old man who was injured by a traffic accident. He was transported to the nearest emergencyhospital. Under the diagnosis of multiple fractures of facial bones and general contusion, he was hospitalized andreceived anti-inflammatory treatment. He was referred to our department for treatment of his intraoral wound.Intraoral examination revealed luxation of the mandibular anterior teeth and detition of the surrounding gingival. CT imaging showed fractures in the left great horn of the hyoid bone, maxilla, orbital floor, nasal bone, and alveolarbone of the mandible. As the patient had only slight swallowing pain, anti-inflammatory treatment was administeredduring hospitalization, without surgery. Half a year since the accident, CT imaging showed slight restorationof the hyoid bone, and the patient has had no symptoms.

Synchrotron-based high-resolution X-ray powder diffraction spectra from the body parts of a snail and bivalve (CaCO 3 ), have been recorded with Pilatus area detector. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15 keV X-rays (λ=0.82666 A). The external shell of these living organisms, is composed of calcium carbonate, which carries strong biological signal. It consists of some light elements, such as, Ca, C and O, which constitute part of the soft tissue and other trace elements. The knowledge of these diffraction patterns and hence the understanding of structures at molecular level are enormous. The application of synchrotron radiation to powder diffraction is well suited for samples of biological nature via changes in their patterns and also to investigate crystallographic phase composition. With the use of Rietveld refinement procedure, to the high-resolution diffraction spectra, we were able to extract the lattice parameters of orthorhombic polymorph of CaCO 3 , the most abundant mineral produced by these living organisms. The small size of the crystallite is a very important factor related to the biological structure. The natural model presents a combination of organic and inorganic phases with nanometer size. For the present study, we also used the scanning electron microscopy (SEM) to explore the associated morphology of the snail and bivalve.

application/pdf, Using a non-radioactive iodine-127 labeled cerebral perfusion agent (I-127 IMP), fluorescent X-ray computed tomography (FXCT) clearly revealed the cross-sectional distribution of I-127 IMP in normal mouse brain in-vivo. Cerebral perfusion of cortex and basal ganglion was depicted with 1 mm in-plane spatial resolution and 0.1 mm slice thickness. Degree of cerebral perfusion in basal ganglion was about 2-fold higher than that in cortical regions. This result suggests that in-vivo cerebral perfusion imaging is realized quantitatively by FXCT at high volumetric resolution.

application/pdf, Fluorescent X-ray CT (FXCT) to depict functional information and phase-contrast X-ray CT (PCCT) to demonstrate morphological information are being developed to analyze the disease model of small animal. To understand the detailed pathological state, integration of both functional and morphological image is very useful. The feasibility of image fusion between FXCT and PCCT were examined by using ex-vivo hearts injected fatty acid metabolic agent (127I-BMIPP) in normal and cardiomyopathic hamsters. Fusion images were reconstructed from each 3D image of FXCT and PCCT. 127I-BMIPP distribution within the heart was clearly demonstrated by FXCT with 0.25 mm spatial resolution. The detailed morphological image was obtained by PCCT at about 0.03 mm spatial resolution. Using image integration technique, metabolic abnormality of fatty acid in cardiomyopathic myocardium was easily recognized corresponding to anatomical structures. Our study suggests that image fusion provides important biomedical information even in FXCT and PCCT imaging.

Tissue response to apatite cement (AC) containing atelocollagen (AC (ate)) was evaluated using conventional AC (c-AC) as a control material. At one week, the only difference between AC (ate) and c-AC was found in the soft tissue response. With c-AC, a moderate inflammatory response was exhibited: small particles of c-AC were scattered in the cutaneous tissue and many foreign body giant cells were aggregated around the scattered c-AC, whereas AC (ate) showed only a slight inflammatory response with few foreign body giant cells. In terms of bone tissue response, difference between AC (ate) and c-AC was observed at four weeks. New bone formation was observed along the cement at the edge of the pre-existing cortical bone in both c-AC and AC (ate). However, in the case of AC (ate), more abundant and thicker new bone was formed along the cement in the bone marrow when compared with c-AC.

Introduction Amyloid positron‐emission tomography (PET) imaging with 11C‐Pittsburgh compound B (PiB) is an effective tool for assessing brain amyloid deposits. PET imaging, however, can suffer from the partial volume effect (PVE). PVE has been corrected using MRI (magnetic resonance imaging) image data. However, correction of the PVE of PET using MRI usually requires two separate procedures, imposing a burden on patients and leading to low throughput and inefficient diagnoses. The advent of PET/computed tomography (PET/CT) may potentially overcome these problems and offer higher throughput and reliable quantification of amyloid plaques and assessment of Alzheimer disease (AD). Methods We investigated the feasibility of correcting PVE in amyloid PET using CT, obtained by PET/CT, instead of MRI. We demonstrated the efficacy of partial volume correction (PVC) based on CT by comparing the results of CT‐based PVC and those of MRI‐based PVC using images acquired from AD patients and controls. Results Both methods were able to perform PVC. Slight but significant differences between standard uptake volume ratio (SUVR) values were noted between the two modalities; these were attenuated by constant multiplication. Conclusion CT will potentially replace MRI for PVC, allowing the use of a single PET/CT scanner for amyloid plaque quantitation.

This paper describes an algebraic reconstruction algorithm that uses total variation (TV) regularization for differential phase contrast computed tomography (DPC-CT) using a limited number of views. In order to overcome over-flattening inherent in TV regularization, a two-step reconstruction process is used: we first reconstruct tomographic images of gradient refractive index from differential projections with TV regularization; these images are then used to compute tomographic images of refractive index by solving the Poisson equation. We incorporate TV regularization in the reconstruction process because the distribution of gradient refractive index is much more flattened than the refractive index. Simulations of the proposed method demonstrate that it can achieve satisfactory image quality from a much smaller number of projections than is required by the Nyquist sampling theorem. We experimentally prove the feasibility of the proposed method using dark field imaging optics at PF-14C beamline at the Photon Factory, KEK. The differential phase contrast projection data was experimentally acquired from a biological sample and DPC-CT images were reconstructed. We show that far fewer projections are needed when the proposed algorithm is used.

X-ray phase-contrast tomography can significantly increase the contrast-resolution of conventional attenuation-contrast imaging, especially for soft-tissue structures that have very similar attenuation. Just as in attenuation-based tomography, phase contrast tomography requires a linear dependence of aggregate beam direction on the incremental direction alteration caused by individual voxels along the path of the X-ray beam. Dense objects such as calcifications in biological specimens violate this condition. There are extensive beam deflection artefacts in the vicinity of such structures because they result in large distortion of wave front due to the large difference of refractive index; for such large changes in beam direction, the transmittance of the silicon analyzer crystal saturates and is no longer linearly dependent on the angle of refraction. This paper describes a method by which these effects can be overcome and excellent soft-tissue contrast of phase tomography can be preserved in the vicinity of such artefact-producing structures.

Irradiation with parallel arrays of thin, planar slices of X-ray beams (microplanar beams, or microbeams) spares normal tissue, including the central nervous system (CNS), and preferentially damages tumors. The effects are mediated, at least in part, by the tissue’s microvasculature that seems to effectively repair itself in normal tissue but fails to do so in tumors. Consequently, the therapeutic index of single-fraction unidirectional microbeam irradiations has been shown to be larger than that of single-fraction unidirectional unsegmented beams in treating the intracranial rat 9L gliosarcoma tumor model (9LGS) and the subcutaneous murine mammary carcinoma EMT-6. This paper presents results demonstrating that individual microbeams, or arrays of parallel ones, can also be used for targeted, selective cell ablation in the CNS, and also to induce demyelination. The results highlight the value of the method as a powerful tool for studying the CNS through selective cell ablation, besides its potential as a treatment modality in clinical oncology.

Effects of functionally gradient calcium phosphate consisting of hydroxyapatite (HAP) and alpha-tricalcium phosphate (alpha-TCP) on proliferation and differentiation of osteoblasts were evaluated using MC3T3-E1 cells. There were no significant differences in the proliferation of MC3T3-E1 cells among HAP-alpha-TCP functionally gradient calcium phosphate, pure HAP, and cell culture plastic wells. mRNA expressions of type I collagen, alkaline phosphate, and osteocalcine were evaluated as indexes of initial; mid-stage, and late-stage osteoblastic differentiation. Basically, HAP-alpha-TCP functionally gradient calcium phosphate and pure HAP enhanced the expressions of the three markers when compared with that of cell culture plastic wells. For type I collagen and alkaline phosphate expressions, HAP-alpha-TCP functionally gradient calcium phosphate showed the same expression level as pure HAP. For osteocalcine expression, HAP-alpha-TCP functionally gradient calcium phosphate showed a higher level than pure HAP. We concluded, therefore, HAP-alpha-TCP functionally gradient calcium phosphate has good potential to be a bone filler material with high osteoconductivity.

Although apatite cement (AC) and sintered hydroxyapatite (s-HAP) are known to show good osteoconductivity, it is not clear whether or not the degree of their osteoconductivity is the same. In addition, it has not been clarified whether or not it is dependent on the type of AC; conventional AC (c-AC), fast-setting AC (fs-AC) or anti-washout AC (aw-AC). The aim of this study was to investigate the effects of ACs on cultured human osteoblasts, as they may provide a useful index of osteoconductivity. Human osteoblasts were cultured on the surfaces of ACs and s-HAP, and were evaluated with respect to cell attachment, proliferation, and differentiation. We found that ACs and s-HAP showed similar cell attachment. No significant difference between ACs and s-HAP was found with respect to the proliferation of osteoblasts. In contrast, we found that the differentiation of osteoblasts was enhanced on the surface of ACs compared with that of s-HAP. However, there was no difference among the types of AC. We therefore concluded that AC may show better osteoconductivity than s-HAP, and that osteoconductivity of AC may be similar, regardless of the type of AC.

We report a case of multiple oral cancer with aplastic anemia.The patient was 25-year-old man who was referred to our department for treatment of a mass in the right side of the maxillary gingiva in July 2001. He was given a diagnosis of aplastic anemia at 7 years of age. The maximum amount of mouth opening was 15mm, and a mass with an ulcer was present in the right upper molar region. Computed tomographic examination showed a mass and bone defect in the right maxillary sinus. A biopsy was performed, and the histopathological diagnosis was squamous cell carcinoma. After radiation therapy (external irradiation with 60Co-γ rays), we conducted operation. Red cell and platelet transfusions as well as granulocyte colony-stimulating factor (G-CSF) administration were performed before operation because of decreased numbers of blood cells, and the patient underwent a pertial maxillectomy.In October 2002, a tumorous lesion appeared in the left side of the mandibular gingiva, and a biopsy revealed squamous cell carcinoma. After the platelet transfusion, resection of the tumor was performed. There has been no evidence of recurrence or metastasis for more than 1 year after surgery.

Purpose. To determine the correlation of reduced retinal thickness in the central papillomacular bundle (CPB) to central visual function, including central retinal sensitivity and visual acuity, in glaucoma patients.Methods. This study enrolled 50 eyes of 50 patients with open-angle glaucoma who were carefully screened for comorbid conditions that can cause decreased central visual function, such as cataracts or macular diseases. We used a novel CPB analysis comprising a program for optical coherence tomography that measured RNFL thickness and GCC thickness in the CPB and divided lengthwise into three parts (upper, middle, and lower CPB). The relationship of these parameters, including conventional macular thickness, to visual field sensitivity in four central standard automated perimetry points (the central four thresholds) and BCVA was analyzed.Results. The two parameters most highly correlated with central four thresholds were macular GCCT and macular RNFLT. The two parameters most highly correlated with BCVA were middle CPB (mid-CPB) GCCT and mid-CPB RNFLT. A multiple regression analysis revealed that mid-CPB GCCT was an independent factor impacting central retinal thresholds and BCVA.Conclusions. Our results suggest that mid-CPB RNFLT and GCCT, parameters of a novel papillomacular bundle analysis, are candidate biomarkers of decreased central visual function in glaucomatous eyes.

Purpose Although the lamina cribrosa (LC) is the primary site of axonal damage in glaucoma, adequate methods to image and measure it are currently lacking. Here, we describe a noninvasive, in vivo method of evaluating the LC, based on swept-source optical coherence tomography (SS-OCT), and determine this method’s ability to quantify LC thickness. Methods This study comprised 54 eyes, including normal (n = 18), preperimetric glaucoma (PPG; n = 18), and normal tension glaucoma (NTG; n = 18) eyes. We used SS-OCT to obtain 3 x 3 mm cube scans of an area centered on the optic disc, and then synchronized reconstructed B- and en-face images from this data. We identified the LC in these B-scan images by marking the visible borders of the LC pores. We marked points on the anterior and posterior borders of the LC in 12 B-scan images in order to create a skeleton model of the LC. Finally, we used B-spline interpolation to form a 3D model of the LC, including only reliably measured scan areas. We calculated the average LC thickness (avgLCT) in this model and used Spearman's rank correlation coefficient to compare it with circumpapillary retinal nerve fiber layer thickness (cpRNFLT). Results We found that the correlation coefficient of avgLCT and cpRNFLT was 0.64 (p < 0.01). The coefficient of variation for avgLCT was 5.1%. AvgLCT differed significantly in the groups (normal: 282.6 ± 20.6 μm, PPG: 261.4 ± 15.8 μm, NTG: 232.6 ± 33.3 μm). The normal, PPG and NTG groups did not significantly differ in age, sex, refractive error or intraocular pressure (IOP), although the normal and NTG groups differed significantly in cpRNFLT and Humphrey field analyzer measurements of mean deviation. Conclusion Thus, our results indicate that the parameters of our newly developed method of measuring LC thickness with SS-OCT may provide useful and important data for glaucoma diagnosis and research.

The in vitro antibiotic release from anti-washout apatite cement using chitosan (aw-AC(chi)) was investigated in a preliminary evaluation. Flomoxef sodium was employed as the antibiotic and was incorporated into the powder phase aw-AC(chi) at up to 10%. The setting times were measured for aw-AC(chi) containing various amounts of flomoxef sodium. X-ray diffraction (XRD) analysis was also conducted for the identification of products. To evaluate the drug release profile, set aw-AC was immersed in saline and the released flomoxef sodium was determined at regular intervals. The setting time was prolonged slightly with the addition of flomoxef sodium. The difference at 10% flomoxef sodium (0% vs. 10%) was not significant (p>0.05), and can be negligible in clinic. The XRD analysis revealed that formation of hydroxyapatite (HAP) from aw-AC(chi) was reduced, even after 24 h, when the aw-AC(chi) contained flomoxef sodium at 8% or more. The flomoxef sodium release from aw-AC(chi) showed the typical profile observed in skeleton type drug delivery system (DDS). Changing the concentration of chitosan can control the rate of drug release from aw-AC. Therefore, we conclude that aw-AC(chi) is a good candidate for potential use as a DDS carrier that may be useful in surgical operations.

Recently, the effects of Zn2+ on osteogenesis stimulation have become major topics in the research fields of bone formation and organism essential elements. Based on the fundamental finding of Zn2+ with respect to osteogenesis stimulation, Ito et al. have prepared Zn doped beta-tricalcium phosphate (ZnTCP) and have reported that ZnTCP enhances the proliferation of MC3T3-E1 cells. In this investigation, we studied the effects of ZnTCP added to apatite cement (AC) with respect to its setting reaction and proliferation of human osteoblastic cells as an initial evaluation for the feasibility of AC containing ZnTCP. Compositional analysis using powder X-ray diffractometer revealed that ZnTCP shows no reactivity with the setting reaction of AC. As a result, the mechanical strength of set AC decreased increasing amounts of added ZnTCP as if ZnTCP acts as a pore in AC. The setting time of AC was not affected by addition of ZnTCP up to 10%. When AC containing ZnTCP was immersed in alpha-MEM containing 10% bovine serum, Zn2+ was released from AC. Larger amounts of Zn2+ were released from AC containing larger amounts of ZnTCP. When human osteoblastic cells were incubated on the surface of AC discs, proliferation of human osteoblastic cells was significantly increased on the surface of AC that contained 5% ZnTCP when compared with that containing no ZnTCP. In contrast, proliferation of human osteoblastic cells decreased on the surface of AC that contained 10% ZnTCP when compared with that free from ZnTCP; indicating cytotoxicity. We concluded therefore, that addition of ZnTCP to AC is useful to enhance the osteoconductivity of AC when release of Zn2+ can be carefully regulated.

Anti-washout-type fast-setting calcium phosphate cement using chitosan (aw-FSCPC(chi)), conventional CPC (c-CPC), CPC mixed with citric acid (CPC(citric)) and CPC mixed with polyacrylic acid (CPC(acrylic)) were implanted subcutaneously in rats immediately after mixing to shed some light on the understanding of the appearance of excellent tissue response to CPC. CPC(citric) and CPC(acrylic) set quickly, similar to aw-FSCPC(chi), but the former two stopped their transformation to apatitic minerals. The c-CPC, which required a long setting time, was found to be crumbled, but the other CPCs maintained the shape at implantation. The aw-FSCPC(chi) and CPC(citric) showed no inflammatory response whereas c-CPC and CPC(acrylic) showed an inflammatory response one week after implantation. A component of the aw-FSCPC(chi) and c-CPC was an apatitic mineral whereas CPC(citric) and CPC(acrylic) showed no transformation to apatite. We concluded that the non-crumbling property plays a more dominant role in the appearance of excellent tissue response to CPC than the transformation to apatite. Also, a non-crumbling property is not a sufficient condition, but a necessary condition for the appearance of the excellent tissue response to CPC.

The basic properties of calcium phosphate cement (CPC) containing atelocollagen, the main component of the organic substrate in bone, were studied in an initial evaluation for the fabrication of modified CPC. The setting time of conventional CPC (c-CPC) was prolonged to over 100 min when c-CPC contained 1% or more atelocollagen. The diametral tensile strength (DTS) of c-CPC decreased linearly with the collagen content, descending to below the detection limit when the c-CPC contained 3% or more atelocollagen. Therefore, use of c-CPC as the base cement seems inappropriate for the fabrication of atelocollagen-containing CPC. In contrast, the cement set at 9–34 min when fast-setting CPC (FSCPC) was used as the base cement and contained 1–5% atelocollagen, respectively. Although addition of atelocollagen resulted in the decrease of DTS of the set mass, the DTS was approximately the same, 6–8 MPa, at contents of atelocollagen between 1% and 5%. When atelocollagen was added to FSCPC, the handling property was improved significantly. The paste also became more adhesive with increase in atelocollagen content. These properties are desirable for its use in surgical procedures since, for example, bony defects can be filled easily and without a space interposed between the bone and cement paste. Although there are some disadvantages for the addition of atelocollagen to CPC, it can be accepted as long as FSCPC was used as the base cement. We conclude that further evaluations of the effects of atelocollagen, such as biocompatibility, bone synthesis, and bone replacement behaviour should be done, using FSCPC as the base cement.